CNN readers from around the world have asked more than 150,000 questions (and counting) about coronavirus. We’re reading as many as we can and answering some of the most popular questions here.
For parents who are fully vaccinated, “our risk of both getting sick and transmitting it to our children is low,” US Surgeon General Dr. Vivek Murthy said.
“But if you’re in an area where there’s a lot of infection, or if you’re worried about that risk of transmission, then wearing a mask — especially in indoor settings when you go out — is the right thing to do. That’s what I do,” said Murthy, the father of two toddlers.
“I want to take every possible measure to protect my child — even though the risk is low — given that I live in an area where there’s a lot of virus being transmitted.”
And with the dominance of the Delta variant, “it bears being cautious because this is being transmitted at a far higher rate than other versions of Covid-19,” the surgeon general said.
For parents who are not vaccinated, the risk of spreading coronavirus to young children is much higher. Murthy said those who are not fully vaccinated “are at great risk” of getting the Delta variant and should wear masks and avoid indoor gatherings until they are fully vaccinated.
The vaccines require an immune system response to work, so millions of Americans who are immunocompromised or take drugs that suppress the immune system might not get as much protection from a vaccine as others do.
That’s why many Americans are counting on fellow Americans to get vaccinated to help protect them, said Dr. Francis Collins, director of the National Institutes of Health.
People who are immunocompromised should be counseled about the potential for reduced immune responses to Covid-19 vaccines and follow prevention measures (including wearing a mask, staying 6 feet apart from others they don’t live with, and avoiding crowds and poorly ventilated indoor spaces) to protect themselves against Covid-19 until advised otherwise by their healthcare provider, the US Centers for Disease Control and Prevention said in a July 16 update.
In that update, the CDC did not say whether immunocompromised people should get an extra dose of vaccine, but said “the safety, efficacy and benefit of additional doses for COVID-19 vaccines in immunocompromised persons continues to be evaluated.”
Some immunocompromised people have decided to get an extra dose of vaccine on their own. For some, antibodies increased; for others, they didn’t.
In June, researchers from Johns Hopkins University suggested that an extra shot may help increase Covid-19 antibody levels for some organ transplant recipients who did not have a full response to their original vaccinations.
“Americans who have been fully vaccinated do not need a booster shot at this time,” said a July 8 joint statement from the US Centers for Disease Control and Prevention and the US Food and Drug Administration.
“We continue to review any new data as it becomes available and will keep the public informed,” the CDC and FDA said. “We are prepared for booster doses if and when the science demonstrates that they are needed.”
The Israeli government said the Pfizer/BioNTech vaccine was about 95.3% effective against coronavirus infections in May. But in June, after the highly contagious Delta variant spread more widely, that number dropped to 64%, the Israeli government said in a brief statement July 5.
The vaccine was still 93% effective in preventing severe disease and Covid-19 hospitalizations, the Israeli government said, compared to 97% reported in the medical journal The Lancet in May.
Pfizer said it’s working to develop a booster dose that will protect people from variants.
So while fully vaccinated people are still well protected, Pfizer and BioNTech are preparing for the possible need for a booster shot down the road, said Dr. Jerome Adams, former US Surgeon General under the Trump administration.
“The companies are thinking about where the hockey puck is going,” Adams said. “The government — FDA, CDC — are looking at where the hockey puck is right now. And they want to reassure Americans your best protection still is a vaccine, and you still have great protection – better than for the flu shot in any given year – even in the face of variants and waning immunity.”
As of April, research showed the Pfizer/BioNTech and Moderna vaccines stayed highly effective for at least six months (and counting).
In July, Johnson & Johnson said research showed its vaccine is effective for at least eight months (and counting).
“Obviously, the people that were in the (vaccine trial) studies that started in October or so, they’re being followed on a regular basis” to help determine how long vaccine immunity lasts, board-certified internist Dr. Jorge Rodriguez said.
“But understand, vaccinations are your best bet right now,” Adams said. “They’re still incredibly effective. And if we have to get a booster, we just have to get a booster. We do that for the flu every single year, so people shouldn’t get too worked up about that.”
“Delay travel until you are fully vaccinated,” the CDC says. Fully vaccinated means at least 2 weeks have passed since your last dose of Covid-19 vaccine.
For those traveling within the US, you “do NOT need to get tested or self-quarantine if you are fully vaccinated or have recovered from COVID-19 in the past 3 months. You should still follow all other travel recommendations,” the CDC says.
Americans traveling internationally should learn about the Covid-19 restrictions at their destination. Those flying back home to the US must provide proof that they have recently tested negative for coronavirus or recently recovered from Covid-19. They should also get a viral test 3 to 5 days after coming home, the CDC says.
For those who aren’t fully vaccinated but must travel, the guidelines are much tougher. The CDC says it’s important to wear a mask; get tested within three days before traveling; maintain physical distance from anyone not traveling with you; and quarantine for 10 days after you return home. (That quarantine period can be reduced to 7 days if you get tested 3 to 5 days after coming home.)
Health experts have varying stances on this.
The US Centers for Disease Control and Prevention has not changed its mask guidance since the highly contagious Delta variant was found in all 50 states and Washington, DC.
“If you are fully vaccinated, you can resume activities that you did prior to the pandemic,” the CDC says. “You can resume activities without wearing a mask or staying 6 feet apart” – except in places where masks are required, such as on public transportation or in some workplaces.
For those ages 2 and up who aren’t fully vaccinated, “you should wear a mask in indoor public places,” the CDC says. Masks are also a good idea for unvaccinated people in crowded outdoor settings or in close contact with other people who aren’t fully vaccinated — especially in areas where coronavirus is rapidly spreading.
States with below-average vaccination rates have, on average, almost triple the rate of new Covid-19 cases compared to states with above-average vaccination rates, according to recent data from Johns Hopkins University.
In places of high Covid-19 spread, people who are fully vaccinated should still take precautions, such as wearing masks, a World Health Organization official said.
“People need to continue to use masks consistently, being in ventilated spaces, hand hygiene, respiratory etiquette – everything … even if you are vaccinated, when you have community transmission ongoing,” WHO Assistant Director-General Dr. Mariangela Simao said June 25.
And because the vaccines are highly effective but not perfect, some health experts said they would keep wearing masks in certain places despite being fully vaccinated.
“If you’re in a low-infection, high-vaccination area, you don’t need to be wearing a mask indoors if you’re fully vaccinated,” said Dr. Ashish Jha, dean of the Brown University School of Public Health.
But the Delta variant is surging in parts of the US, including southwest Missouri — where Covid-19 patients are filling up hospital beds and getting transferred to other hospitals.
“If I were in southwest Missouri right now, I’m fully vaccinated, but I would be wearing a mask indoors,” Jha said July 5.
One vaccine is already available for children ages 12 and up, and clinical trials are underway for younger children.
Pfizer/BioNTech’s vaccine is the only one currently authorized for people ages 12 and up. The vaccine is now being tested in children between 6 months and 11 years old. If all goes well, Pfizer said, it plans to ask the US Food and Drug Administration in September to authorize the vaccine for children ages 2 to 11 years.
Moderna’s vaccine is currently authorized for adults 18 and older. In May, the company said early trial data showed the vaccine is safe and appears to be effective in 12- to 17-year-olds. In June, Moderna said it has asked the FDA to authorize its vaccine for the 12-to-17 age group.
Moderna is also testing various doses of its vaccine in younger children between ages 6 months through 11 years. If all goes well, Moderna said, children under age 12 could be eligible for the vaccine this winter or in early 2022.
Johnson & Johnson said it plans to start testing its Covid-19 vaccine in adolescents starting this fall. Its single-dose vaccine is currently authorized for adults ages 18 and up.
J&J said it’s planning four late-stage vaccine trials for children. This first trial will focus on 12- to 17-year-olds, and the others will expand to include younger children. In total, J&J plans to enroll a minimum of 4,500 pediatric participants up to age 17.
“To keep children safe, and ultimately to achieve herd immunity, it is imperative that COVID-19 vaccine clinical trials continue to move forward in this population,” J&J said in a July 1 email to CNN.
Children can be more reluctant because they’re more sensitive to new things than adults are, said Christopher Willard, a psychiatry lecturer at Harvard Medical School.
“There’s also the weird psychological aspect of not being able to see their own face or other people’s faces and facial expressions,” which can hinder their feelings of comfort or safety, he said.
To ease your child’s mask hesitancy, try buying or making masks with fun designs on them. Or have your child customize his or her own masks by drawing on them with markers.
You can also order children’s face masks with superheroes on them or show your kids photos of their favorite celebrities wearing masks.
It’s also a good idea to set an example by wearing a mask yourself. Show your children your own mask, and let them know that by wearing one, they’ll be just like Mom or Dad.
Yes, research suggests – as long as you’re fully vaccinated and don’t skip a dose.
Two doses of the Pfizer/BioNTech vaccine offered 88% protection against symptomatic Covid-19 caused by the Delta variant, Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said in late June.
But those who got only one dose of the Pfizer/BioNTech vaccine had just 33% protection against the Delta variant, US Surgeon General Dr. Vivek Murthy said.
“The key is: Get vaccinated. Get both doses,” Murthy said.
Moderna’s two-dose vaccine was found in lab experiments to work against new variants such as the Delta strain, the company said. Scientists used serum samples from eight participants taken a week after they received their second dose of the Moderna vaccine.
And researchers say the single-dose Johnson & Johnson vaccine also appears to work against the Delta variant. The researchers studied blood taken from eight vaccinated volunteers and tested it against an engineered version of the spike protein of the Delta variant.
“A single dose of the Johnson & Johnson COVID-19 vaccine generated neutralizing antibodies against a range of SARS-CoV-2 variants of concern, which increased over time, including against the increasingly prevalent and more transmissible Delta (B.1.617.2) variant,” Johnson & Johnson said on July 1.
But the Delta variant is more contagious than both the original strain of novel coronavirus and the Alpha (B.1.1.7) strain, the surgeon general said.
“It’s yet another reason to get vaccinated quickly,” Murthy said.
The Delta Plus variant (B.1.617.2.1) is a new and slightly changed offshoot of the highly contagious Delta variant (B.1.617.2).
All variants carry clusters of mutations. Delta Plus is different from Delta because it has an extra mutation called K417N. That mutation affects the spike protein – the part of the virus that attaches to human cells it infects.
The Indian government’s Covid-19 genome sequencing body said the Delta Plus variant exhibits several worrying traits such as increased transmissibility, stronger binding to receptors of lung cells, and a potential reduction in antibody response.
It’s not yet clear what effect the mutation may have on vaccine efficacy. But it could give the variant “significant vaccine escape properties,” warned Julian Tang, professor of respiratory sciences at the University of Leicester.
Most of the coronavirus vaccines are designed to train the body to recognize the spike protein, or parts of it – which is where Delta Plus’ extra mutation is.
But there isn’t enough evidence to determine anything conclusively yet. The World Health Organization is tracking Delta Plus to determine its transmissibility and severity, said Maria Van Kerkhove, WHO’s technical lead on Covid-19.
The US is among at least 11 countries that have reported cases of the emerging Delta Plus variant. But Delta Plus has not made up a significant share of sequenced Covid-19 cases in the US, according to June data from the CDC.
In late June, the genetic sequencing company Helix said it has seen some intermittent cases of the Delta Plus variant in the US.
The more people who get infected with a virus, the more chances the virus has to evolve through mutation.
Viruses mutate all the time as they replicate in people who are infected. Some mutations aren’t very important. But if the mutations are significant, they can lead to more contagious or more dangerous new variants of a virus.
“Think of a virus as a necklace full of different-colored beads,” board-certified internist Dr. Jorge Rodriguez said.
“And in position No. 1, you need a red bead. Position No. 2 is a green bead. That’s the genetic code – that sequence of bead colors,” he said.
“When a virus replicates, it is supposed to make an exact replica of those bead colors. But every once in a while, maybe a green bead gets into where a red bead is supposed to be.”
When mutations give the virus an advantage — such as the ability to replicate faster, or to hide from the immune system – that version will outcompete others.
The only way to get rid of variants is to lower the number of infections, said Penny Moore, an expert in viruses at South Africa’s National Institute for Communicable Diseases.
That’s a big reason why doctors urge people to get vaccinated as soon as they can. Those who don’t get vaccinated aren’t just risking their own health — they’re also jeopardizing the health of others, infectious disease specialists say.
“Unvaccinated people are potential variant factories,” said Dr. William Schaffner, a professor in the Division of Infectious Diseases at Vanderbilt University Medical Center.
“The more unvaccinated people there are, the more opportunities for the virus to multiply.”
“It is a normal human reaction to be afraid,” pediatrician Dr. Edith Bracho-Sanchez said. “They’re having a normal reaction, and perhaps they haven’t been able to sit down with their physician.”
She suggests finding a time to have a calm, rational conversation — when neither person is angry or likely to start a fight.
“The first thing I would say is ‘I get it. I totally get where you’re coming from and I understand that you’re concerned about this,’” Bracho-Sanchez said.
It’s also important to cite scientific data — like the truth about side effects, the safety of Covid-19 vaccines and why it’s important for young, healthy people to get vaccinated.
Research is still evolving, but a recent study examining antibodies suggests you could be immune for months after infection.
“Although this cannot provide conclusive evidence that these antibody responses protect from reinfection, we believe it is very likely that they will decrease the odds ratio of reinfection,” researchers from Mount Sinai wrote.
“It is still unclear if infection with SARS-CoV-2 [the scientific name for the novel coronavirus] in humans protects from reinfection and for how long.”
There have been some reports of people getting infected twice within several months. Doctors said a 25-year-old Nevada man appeared to be the first documented case of Covid-19 reinfection in the US. He was first diagnosed in April 2020, then recovered and tested negative twice. About a month later, he tested positive again.
A separate team of researchers said a 33-year-old man living in Hong Kong had Covid-19 twice, in March and August of 2020.
Last year, an 89-year-old Dutch woman – who also had a rare white blood cell cancer – died after catching Covid-19 twice, experts said. She became the first known person to die after getting reinfected.
“Yes, you should be vaccinated regardless of whether you already had COVID-19,” the CDC says.
“That’s because experts do not yet know how long you are protected from getting sick again after recovering from COVID-19.”
“There are actually six other coronaviruses – MERS and SARS and four other viruses that create the common cold. They don’t seem to do very well at creating long-term immunity,” epidemiologist Dr. Larry Brilliant said.
“Many of the vaccines that we’ve made in history are actually stronger than the virus is itself at creating immunity.”
Both the Pfizer/BioNTech and Moderna vaccines have been shown to give about 95% protection against symptomatic Covid-19, and both are virtually 100% effective against severe Covid-19 illness. In their clinical trials, no one who was vaccinated died from Covid-19.
The Johnson & Johnson vaccine was 72% effective against Covid-19 among US trial participants and 85% effective against severe Covid-19. Like the other two vaccines, no one who was vaccinated during the clinical trial died from Covid-19.
But Johnson & Johnson’s vaccine was tested later – when coronavirus cases were surging and new variant strains were spreading more widely.
And unlike the Moderna and Pfizer/BioNTech vaccines, which require two doses, the Johnson & Johnson vaccine requires only one dose.
Dr. Anthony Fauci said he does not foresee a nationwide Covid-19 vaccine mandate.
But if only half of all Americans are willing to get vaccinated, Covid-19 could stick around for years, said Dr. Francis Collins, director of the National Institutes of Health.
Health experts say if you don’t get a vaccine, the consequences will extend far beyond yourself — even if you’re young and healthy now. Not only would you be more vulnerable to getting severely sick with Covid-19 or “long Covid” — it will also be harder to achieve herd immunity through vaccination.
In other words: Getting a vaccine is critical for slowing or possibly ending this pandemic. And that will help everyone get back to normal, faster.
“It’s all free. The government is paying for this,” said Dr. Paul Offit, director of the Vaccine Education Center at the Children’s Hospital in Philadelphia.
Some people have reported feeling temporary, flu-like symptoms. Don’t freak out if this happens to you, health experts say.
“These are immune responses, so if you feel something after vaccination, you should expect to feel that,” said Patricia Stinchfield of Children’s Hospitals and Clinics of Minnesota.
“And when you do, it’s normal that you have some arm soreness or some fatigue or some body aches or even some fever,” Stinchfield said.
Read more about what to do if you do get side effects and why side effects are often a good sign.
The Pfizer/BioNTech vaccine has shown no serious safety concerns, Pfizer said. Pfizer has said side effects “such as fever, fatigue and chills” have been “generally mild to moderate” and lasted one to two days.
Moderna said its vaccine did not have any serious side effects. It said a small percentage of trial participants had symptoms such as body aches and headaches.
With the Johnson & Johnson vaccine, the most common side effects were pain at the injection site, headache, fatigue and muscle pain. While the CDC recommends the Johnson & Johnson vaccine, “women younger than 50 years old especially should be aware of the rare but increased risk of thrombosis with thrombocytopenia syndrome (TTS),” the agency says. “TTS is a serious condition that involves blood clots with low platelets. There are other COVID-19 vaccine options available for which this risk has not been seen.”
Aerosolized spread is the potential for coronavirus to spread not just by respiratory droplets, but by even smaller particles called aerosols that can float in the air longer than droplets and can spread farther than 6 feet.
Respiratory aerosols and droplets are released when someone talks, breaths, sings, sneezes or coughs. But the main difference is size.
“If you have droplets that come out of a person, they generally go down within 6 feet,” said Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases.
But aerosols (aka droplet nuclei) are smaller – less than 5 microns in diameter, according to the World Health Organization.
“Aerosol means the droplets don’t drop immediately,” Fauci said. “They hang around for a period of time.”
This becomes “very relevant” when you are indoors and there is poor ventilation, he said.
Multiple case studies suggest coronavirus can spread well beyond 6 feet through airborne transmission, such as during choir practices, said Dr. Amy Compton-Phillips, chief clinical officer of Providence Health System.
In Washington state, for example, 53 members of a choir fell sick and two people died after one member attended rehearsals and later tested positive for Covid-19.
Last July, 239 scientists backed a letter urging public health agencies to recognize the potential for aerosolized spread.
“There is significant potential for inhalation exposure to viruses in microscopic respiratory droplets (microdroplets) at short to medium distances (up to several meters, or room scale), and we are advocating for the use of preventive measures to mitigate this route of airborne transmission,” the letter said.
The Crisis Text Line is available texting to 741741. Trained volunteers and crisis counselors are staffed 24/7, and the service is free.
The Substance Abuse and Mental Health Services Administration Disaster Distress Helpline provides 24/7, 365-day-a-year crisis counseling and support to people experiencing emotional distress related to disasters. Call 1-800-985-5990 or text TalkWithUs to 66746 to connect with a trained crisis counselor.
For health care professionals and essential workers, For the Frontlines offers free 24/7 crisis counseling and support for workers dealing with stress, anxiety, fear or isolation related to coronavirus.
For more resources, check out CNN’s guide to giving and getting help during the pandemic.
More than 40% of US adults have at least one underlying condition that can put them at higher risk of severe complications, according to the CDC.
Those conditions include obesity, chronic obstructive pulmonary disease, heart disease, diabetes, and chronic kidney disease, according to the CDC.
People who have cancer, an organ transplant, sickle cell anemia, poorly controlled HIV or any autoimmune disorder are also at higher risk.
Covid-19 patients with pre-existing conditions — regardless of their age — are 6 times more likely to hospitalized and 12 times more likely to die from the disease than those who had no pre-existing conditions, CNN Chief Medical Correspondent Dr. Sanjay Gupta said.
While young, healthy people are less likely to die from Covid-19, many are suffering long-term effects from the disease.
Unvaccinated people from different households in a car should wear face masks, said Dr. Aaron Hamilton of the Cleveland Clinic.
“You should also wear one if you’re rolling down your window to interact with someone at a drive-thru or curbside pickup location,” Hamilton said.
It’s also smart to keep the windows open to help ventilate the car and add another layer of safety, said Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases.
If there are tissues nearby, you can take your mask off and sneeze into the tissue before putting your mask back on, CNN Chief Medical Correspondent Dr. Sanjay Gupta said.
For kids in school — or anyone else who might have to wear a mask all day — keep a backup mask in a baggie in case the first mask gets dirty. You can put the dirty mask in the baggie.
It’s also a good idea to keep backup masks in your car in case of any mask accidents.
Yes, that’s a good idea because cell phones are basically “petri dishes in our pockets” when you think about how many surfaces you touch before touching your phone.
You should regularly disinfect your mobile phone anyway, with or without a coronavirus pandemic.
“There’s probably quite a lot of microorganisms on there, because you’re holding them against your skin, you are handling them all the time, and also you’re speaking into them,” said Mark Fielder, a professor of medical microbiology at Kingston University.
“And speaking does release droplets of water just in normal speech. So it’s likely that a range of microbes – including Covid-19, should you happen to be infected with that virus – might end up on your phone.”
Watch the best ways to disinfect your cell phone here.
There are certainly risks if you’re not vaccinated.
Coronavirus often spreads more easily indoors rather than outdoors — especially if you’re indoors for an extended period of time.
Researchers have also found that heavy breathing and singing can propel aerosolized viral particles farther and increase the risk of transmission.
During one fitness instructor workshop, about 30 participants with no symptoms trained intensely for four hours, according to research published by the CDC. Eight participants later tested positive, and more than 100 new cases of coronavirus were traced back to that fitness workshop.
To help mitigate the risk, many gyms are limiting capacity or requiring masks.
And while health experts have recommended staying 6 feet away from others, it’s smart to keep even more distance than that at the gym.
“With all the heavy breathing, you may even want to double the usual 6 feet to 12 feet, just to be safe,” CNN Chief Medical Correspondent Dr. Sanjay Gupta said.
Doctors say wearing eye protection (in addition to face masks) could help some people, but it’s not necessary for everyone.
Teachers who have younger students in the classroom are “likely to be in environments where children might pull down their masks, or not be very compliant with them,” epidemiologist Saskia Popescu said. “There is concern that you could get respiratory droplets in the eyes.”
If you’re a health care worker or taking care of someone at home who has coronavirus, it’s smart to wear eye protection, said Dr. Thomas Steinemann, clinical spokesperson for the American Academy of Ophthalmology.
(Note: Regular glasses or sunglasses aren’t enough, because they leave too many gaps around the eyes.)
But if you’re vaccinated or not in a high-risk situation, wearing goggles isn’t necessary.
While it’s still possible to get Covid-19 through the eyes, that scenario is less likely than getting it through your nose or mouth, Steinemann said.
He said if a significant number of people were getting coronavirus through their eyes, doctors would probably see more Covid-19 patients with conjunctivitis, also known as pink eye (though having pink eye doesn’t necessarily mean you have coronavirus).
The CDC does not recommend using plastic face shields for everyday activities or as a substitute for face masks. There are a few exceptions, such as for those who are hearing-impaired and rely on lip-reading or those who have physical or mental health conditions that would be exacerbated by wearing a cloth face mask.
“Cloth face coverings are a critical preventive measure and are most essential in times when social distancing is difficult,” the CDC says.
Clinical and laboratory studies show cloth face coverings reduce the spray of droplets when worn over the nose and mouth – what the CDC refers to as “source control.” And many people are contagious even when they don’t have any symptoms and don’t know they’re infected.
Face shields worn in addition to masks can provide an added layer of protection and can also help people stop touching their faces. Workers who are around people for long periods of time, such as grocery store workers or hospital personnel, may want to wear face shields in addition to masks, to increase their protection.
If someone must use a face shield without a mask, the CDC says the shield “should wrap around the sides of the wearer’s face and extend to below the chin. Disposable face shields should only be worn for a single use. Reusable face shields should be cleaned and disinfected after each use.”
First, make sure the top of your mask fits snugly against your skin (to minimize vapor from your breath from going up toward your eyes). Then put your glasses over the snug-fitting top portion of your mask.
If that doesn’t do the trick, soap and water can create a barrier that prevents glasses from fogging up. Here’s how.
Yes. And the increased risk applies to cancer patients of all ages, the CDC says.
“Having cancer currently increases your risk of severe illness from COVID-19,” the CDC says. “At this time, it is not known whether having a history of cancer increases your risk.”
Researchers found that patients whose cancer was getting worse or spreading were more than five times more likely to die in a month if they caught Covid-19.
But there are steps cancer patients can take to stay as healthy as possible:
Technically, it can, but HVAC (heating/ventilation/air conditioning) systems are not thought to be a significant factor in the spread of coronavirus.
Many modern air conditioning systems will either filter out or dilute the virus. Ventilation systems with highly effective filters are a key way to eliminate droplets from the air, said Harvard environmental health researcher Joseph Gardner Allen.
Filters are rated by a MERV system – their “minimum efficiency reporting value” that specifies their ability to trap tiny particles. The MERV ratings go from 1 to 20. The higher the number, the better the filtration.
HEPA filters have the highest MERV ratings, between 17 and 20. HEPA filters are used by hospitals to create sterile rooms for surgeries and to control infectious diseases. They’re able to remove 99.97% of dust, pollen, mold, bacteria and other airborne particles as small as 0.3 microns.
For context, this coronavirus is thought to be between 0.06 to 1.4 microns in size.
But “HEPA filtration is not always going to be feasible or practical,” Allen said. “But there are other filters that can do the job. What is recommended now by the standard setting body for HVAC is a MERV 13 filter.”
High-efficiency filters in the 13-to-16 MERV range are often used in hospitals, nursing homes, research labs and other places where filtration is important.
“If you’re an owner of a home, building or mall, you want to have someone to assess your system and install the largest MERV number filter the system can reliably handle without dropping the volume of air that runs through it,” advised Erin Bromage, an associate professor of biology at the University of Massachusetts Dartmouth.
“In addition, virtually all modern air conditioning systems in commercial buildings have a process called makeup air where they bring in air from outside and condition it and bring it inside,” Bromage said. “It’s worse in regards to energy, but the more outside air we bring in, the more dilution of the virus we have and then the safer you are.”
Asymptomatic describes a person who is infected but does not have symptoms. With Covid-19, asymptomatic carriers can still easily infect others without knowing it. So if you’re infected but don’t feel sick, you could still get others very sick.
Some medical professionals differentiate between truly asymptomatic carriers – those who don’t currently have and will never have symptoms – from “pre-symptomatic” carriers – those who don’t have symptoms now, but will get them later. But the general public often uses the term “asymptomatic” to describe both categories of infected people.
Regardless of which term you use, researchers have found that about half of coronavirus transmissions happen between people who don’t have any symptoms. And in some cases, people are more contagious before they start showing symptoms.
An N95 respirator provides the best protection. But throughout the pandemic, N95s have been in high demand and short supply.
As for other masks, different types have different levels of effectiveness, according to researchers at Florida Atlantic University.
They compared four types of face masks commonly used by the public: a stitched mask with two layers of fabric, a commercial cone mask, a folded handkerchief, and a bandana. Researchers tested each to see which would likely offer the most protection if someone coughed or sneezed.
— The stitched mask with two layers of fabric performed the best, with droplets traveling only 2.5 inches.
— With a cone-style mask, the droplets traveled about 8 inches.
— A folded handkerchief performed worse, with droplets traveling 1 foot, 3 inches.
— The bandana gave the least amount of protection of the cloth masks tested, with droplets traveling 3 feet.
— Still, any kind of cloth mask is better than none, the researchers found. Without any covering, droplets were able to travel 8 feet.
“People need to know that wearing masks can reduce transmission of the virus by as much as 50%, and those who refuse are putting their lives, their families, their friends, and their communities at risk,” said Dr. Christopher Murray, director of the University of Washington’s Institute for Health Metrics and Evaluation.
The odds of transmitting coronavirus through sex hasn’t been thoroughly studied, though it has been found to exist in men’s semen.
But we do know Covid-19 is a highly contagious respiratory illness that can spread via saliva, coughs, sneezes, talking or breathing — with or without symptoms of illness.
So three Harvard physicians examined the likelihood of getting or giving Covid-19 during sex and made several recommendations.
For partners who haven’t been isolating together, they should wear masks and avoid kissing, the authors write.
In addition to wearing masks, people who have sex with partners outside of their home should also shower before and after; avoid sex acts that involve the oral transmission of bodily fluids; clean up the area afterward with soap or alcohol wipes to reduce their likelihood of infection.
Earlier in this pandemic, scientists didn’t know how easily this new virus spreads between people without symptoms, nor did they know how long infectious particles could linger in the air. There was also a shortage of N95 respirators and face masks among health care workers who were quickly overwhelmed with Covid-19 patients.
But since then, the CDC, the US Surgeon General and other doctors have changed their recommendations and are now urging the widespread use of face masks.
The CDC now says the public needs to “cover your mouth and nose with a cloth face cover when around others.”
“Everyone should wear a cloth face cover when they have to go out in public, for example to the grocery store or to pick up other necessities,” the CDC said.
Scientists have made many recent discoveries about the new coronavirus, including:
In other words, it’s not just people who are sneezing and coughing who can spread coronavirus. It’s often people who look completely normal and don’t have a fever. And that could include you.
Doctors say getting vaccinated is the best way to prevent coronavirus infection.
If you’re not vaccinated, it’s best to take the stairs if you can. But if you can’t, emergency room physician Dr. Leana Wen offers several tips:
For those not fully vaccinated, try to avoid public restrooms if you can, said microbiologist Ali Nouri, president of the Federation of American Scientists. But he acknowledged that’s not always possible: “Sometimes when you gotta go, you gotta go.”
Close contact with others is the most significant risk in a public restroom, Nouri said. So if there’s a single-person bathroom available that doesn’t have multiple stalls, using that might be best.
If you do use a multi-stall public restroom, Nouri offers the following tips:
“It’s probably safe if you’re not at home,” said Dr. Leana Wen, an emergency room physician. She suggested leaving the windows open to improve ventilation and asking the cleaners to use your own cleaning supplies so they don’t bring items that have been in other people’s houses.
That’s “not a great idea,” said Dr. Joseph Vinetz, a professor of infectious diseases at Yale School of Medicine. “We have no evidence about that.”
“If there’s a metal piece in an N95 or surgical mask and even staples, you can’t microwave them,” he said. “It’ll blow up.”
Vinetz said cloth masks can be washed and reused, and even disposable masks can be reused if you let them sit for several days.
To disinfect masks that you can’t wash, Vinetz recommends leaving them in a clean, safe place in your home for a few days. After that, it should no longer be infectious, as this coronavirus is known to survive on hard surfaces for only up to three days.
Doctors strongly recommend performing CPR when someone needs it.
You could be hundreds of times more likely to save that dying person’s life than you are to die from Covid-19 if you contract it after performing CPR, according to a report published by a group of Seattle emergency room physicians in the journal Circulation.
But it’s important to act quickly for CPR to be effective.
“The chance of survival goes down by 10% for every minute without CPR,” said Dr. Comilla Sasson, vice president for science and innovation in emergency cardiovascular care at the American Heart Association. “It’s a 10-minute window to death in many cases.”
If you’re not certified in CPR, performing chest compressions could also buy more time until help arrives. Bystanders should “provide high-quality chest compressions by pushing hard and fast in the middle of the victim’s chest, with minimal interruptions,” the American Heart Association said.
If you’re not sure how “fast” to do to those chest compressions, singing any of these popular songs will help you get the right rhythm.
Randomly spraying open places is largely a waste of time, health experts say.
It can actually do more harm than good. “Spraying disinfectants can result in risks to the eyes, respiratory or skin irritation,” the World Health Organization said.
“Spraying or fumigation of outdoor spaces, such as streets or marketplaces, is also not recommended to kill the COVID-19 virus or other pathogens because disinfectant is inactivated by dirt and debris, and it is not feasible to manually clean and remove all organic matter from such spaces,” the WHO said.
“Moreover, spraying porous surfaces, such as sidewalks and unpaved walkways, would be even less effective.” Besides, the ground isn’t typically a source of infection, the WHO said.
And once the disinfectant wears off, an infected person could easily contaminate the surface again.
And when people are “shouting and cheering loudly, that does produce a lot of droplets and aerosolization that can spread the virus to people,” said Dr. James Phillips, a physician and assistant professor at George Washington University Hospital.
So doctors and officials say its important to get vaccinated or wear a face mask and try to keep your distance from others as much as possible.
No. The US Food and Drug Administration says you don’t need to wash fresh produce with soap and water, but you should rinse it with plain water.
But it’s still important to wash your hands with soap and water frequently because we often touch our faces without realizing it. And that’s a way coronavirus can spread.
You don’t have to worry about getting coronavirus by “eating” it, though. Even if coronavirus does get into your food, your stomach acid would kill it, said Dr. Angela Rasmussen, a virologist at Columbia University.
This “Contact tracing 101” article explains how contact tracing works, how it quashed previous outbreaks, who can get hired, and why tracing is critical to helping reopen economies.
But the US hasn’t been doing nearly enough contact tracing, experts say. Here’s why.
Hot water is best for killing bacteria and viruses in your laundry. But you don’t want to use that kind of scalding hot water on your skin.
Warm water is perfectly fine for washing your hands — as long as you wash them thoroughly (like this) and for at least 20 seconds. (To time yourself, you can hum the “Happy Birthday” song twice or sing a couple of verses from any of these hit songs from the past several decades.)
Cold water will also work, “but you have to make sure you work really vigorously to get a lather and get everything soapy and bubbly,” said chemist Bill Wuest, an associate professor at Emory University. To do that, you might need to sing “Happy Birthday” three times instead of twice.
“Warm water with soap gets a much better lather – more bubbles,” Wuest said. “It’s an indication that the soap is … trying to encapsulate the dirt and the bacteria and the viruses in them.”
Yes you can, said Dr. Joseph Vinetz, an infectious diseases professor at Yale School of Medicine.
To disinfect masks that you can’t wash, Vinetz recommends leaving them in a clean, safe place in your home for a few days. After that, it should no longer be infectious, as this coronavirus is known to survive on hard surfaces for only up to three days.
You can reuse cloth masks, too. Just launder them between each use on a high-heat setting.
Learn more about which masks you shouldn’t buy and how you can make your own (without having to sew) here.
Not necessarily. Antibodies are a body’s response to bacteria or viruses. But this novel coronavirus is so new, it’s still not clear whether having antibodies to it means you have long-term protection from getting reinfected.
“The thing we don’t know yet is what is the relationship between the level of antibody and the degree of your protection,” Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, told Snapchat’s “Good Luck America” show.
“So you may be positive for an antibody, but not enough to protect you.”
There’s also a risk that some antibody tests might confuse the novel coronavirus with other coronaviruses, like the ones that cause the common cold.
Please don’t. The CDC advises using hand sanitizer that contains at least 60% alcohol.
Vodka typically contains between 35% and 46% percent alcohol.
If the stores are out of hand sanitizer and you want to make your own, the Nebraska Medical Center offers this recipe:
What you’ll need:
In a mixing bowl, stir isopropyl alcohol and aloe vera gel together until well blended.
Add 8-10 drops of scented essential oil (optional, but nice). Stir.
Pour the homemade hand sanitizer into an empty container and seal. Write “hand sanitizer” on a piece of masking tape and attach to the bottle.
This is not a good time to be vaping or smoking anything, including weed.
“Vaping affects your lungs at every level. It affects the immune function in your nasal cavity by affecting cilia, which push foreign things out,” said Prof. Stanton Glantz, director of the Center for Tobacco Research Control and Education at University of California San Francisco.
When you vape, “the ability of your upper airways to clear viruses is compromised,” Glantz said.
Tobacco smokers are at especially high risk. In a study from China, where the first Covid-19 outbreak occurred, smokers were 14 times more likely to develop severe complications than non-smokers.
Even occasionally smoking marijuana can put you at greater risk.
“What happens to your airways when you smoke cannabis is that it causes some degree of inflammation, very similar to bronchitis, very similar to the type of inflammation that cigarette smoking can cause,” said pulmonologist Dr. Albert Rizzo, chief medical officer for the American Lung Association.
“Now you have some airway inflammation, and you get an infection on top of it. So yes, your chance of getting more complications is there.”
Coronavirus isn’t just infecting young people. It’s killing young, healthy people as well.
Dimitri Mitchell, 18, admits he had a “false sense of security.” But he was later hospitalized with coronavirus and now wants everyone to take it seriously.
“I just want to make sure everybody knows that no matter what their age is, it can seriously affect them. And it can seriously mess them up, like it messed me up,” the Iowa teen said.
“Four days in, the really bad symptoms started coming along. I started having really bad outbreaks, like sweating, and my eyes were really watery. I was getting warmer and warmer, and I was super fatigued. … I would start experiencing the worst headaches I’ve ever felt in my life. They were absolutely horrible.”
Eventually, the teen had to be hospitalized. His mother said she worried he might “fall asleep and never wake up.”
Mitchell is now recovering, but has suffered from long-term effects.
“I just hope everybody’s responsible, because it’s nothing to joke about,” he said. “It’s a real problem, and I want everybody to make sure they’re following social distancing guidelines and the group limits. And just listen to all the rules and precautions and stay up to date with the news and make sure they’re informed.”
No. That’s just a hoax going around the internet.
“The theory that 5G might compromise the immune system and thus enable people to get sick from corona is based on nothing,” said Eric van Rongen, chairman of the International Commission on Non-Ionizing Radiation Protection (ICNIRP).
Learn more about how 5G really works and why this hoax makes no sense.
Ideally, you should limit your children’s potential exposures to coronavirus and work out the safest plan possible with your ex.
The problem: Some state and county family courts might be closed, or open only for emergencies involving abuse or endangerment. So it might be difficult to formally modify pre-existing custody agreements.
But some states may be offering some flexibility during the pandemic. And there may be creative solutions, such as spending more time with one parent now in exchange for extra time with the other parent after the pandemic ends.
For unvaccinated people, the CDC “recommends wearing cloth face coverings in public settings where other social distancing measures are difficult to maintain (e.g., grocery stores and pharmacies).”
There are several key points:
Most coronavirus patients don’t need to be hospitalized. “The vast majority of people – about 80% – will do well without any specific intervention,” said Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases.
Those patients should get plenty of rest, hydrate frequently and take fever-reducing medication.
“The current guidance – and this may change – is that if you have symptoms that are similar to the cold and the flu and these are mild symptoms to moderate symptoms, stay at home and try to manage them,” said Dr. Patrice Harris, president of the American Medical Association.
But about 20% of coronavirus patients get advanced disease. “Older patients and individuals who have underlying medical conditions or are immunocompromised should contact their physician early in the course of even mild illness,” the CDC says.
The CDC also says you should get immediate help if you have:
“This list is not all inclusive,” the CDC says. “Please consult your medical provider for any other symptoms that are severe or concerning.”
No, the water supply is not at risk.
“The COVID-19 virus has not been detected in drinking water,” the CDC says. “Conventional water treatment methods that use filtration and disinfection, such as those in most municipal drinking water systems, should remove or inactivate the virus that causes COVID-19.”
So there’s no need to hoard drinking water, said Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases. Fauci said he and his wife are still drinking tap water.
It may be difficult to know whether your loved one has coronavirus or another illness. So it’s critical to play it safe and not infect yourself and, in turn, others. The CDC suggests:
Fatigue, fever, dry cough, difficulty breathing and the loss of taste or smell are some of the symptoms of Covid-19.
Symptoms can appear anywhere from 2 days to 2 weeks after exposure, the CDC says. But some people get no symptoms at all and can infect others without knowing it.
The illness varies in its severity. And while many people can recover at home just fine, some people — including young, previously healthy adults — are suffering long-term symptoms.
Yes, you can make both at home.
“Unexpired household bleach will be effective against coronaviruses when properly diluted” if you’re trying to kill coronavirus on a non-porous surface, the US Centers for Disease Control and Prevention said.
The CDC’s recipe calls for diluting 5 tablespoons (or ⅓ cup) of bleach per gallon of water, or 4 teaspoons of bleach per quart of water.
What you’ll need:
In a mixing bowl, stir isopropyl alcohol and aloe vera gel together until well blended.
Add 8-10 drops of scented essential oil (optional, but nice). Stir.
Pour the homemade hand sanitizer into an empty container and seal.
Write “hand sanitizer” on a piece of masking tape and attach to the bottle.
But there are exceptions. Employers who make workers with Covid-19 come in may be violating Occupational Safety and Health Administration [OSHA] regulations, said Donna Ballman, who heads an employee advocacy law firm in Florida.
But there is no federal mandate that requires companies to offer paid sick leave, and almost a quarter of all US workers don’t get it, according to 2019 government data. Some state and local governments have passed laws that require companies to offer paid sick leave.
The Family and Medical Leave Act (FMLA) can sometimes protect a worker’s job in the event they get sick, but it won’t guarantee they get paid while they’re out.
Employee advocates urge businesses to consider the special circumstances of the Covid-19, and some already have
The Society for Human Resource Management recommends companies “actively encourage sick employees to stay home, send symptomatic employees home until they are able to return to work safely, and require employees returning from high-risk areas to telework during the incubation period (of 14 days).”
If a manager feels an employee’s illness poses a direct threat to colleagues’ safety, the manager may be able to insist the employee be evaluated by a doctor, said Alka Ramchandani-Raj, an attorney specializing in workplace safety.
Since Covid-19 is a respiratory disease, some airlines are now requiring passengers to wear face masks during the flight, except for while eating or drinking.
Health experts suggest eating, drinking and using the restroom before getting on the plane, to eliminate the need to take off your mask or go into a cramped lavatory on board.
And always be mindful of where your hands have been, travel medicine specialist Dr. Richard Dawood said.
Airport handrails, door handles and airplane lavatory levers are notoriously dirty.
“It is OK to touch these things as long as you then wash or sanitize your hands before contaminating your face, touching or handling food,” Dawood said.
“Hand sanitizers are great. So are antiseptic hand wipes, which you can also use to wipe down armrests, remote controls at your seat and your tray table.”
Stay home. Call your doctor to talk about your symptoms and let them know you’re coming for an appointment so they can prepare for your visit, the CDC says.
Only a Covid-19 test can diagnose you with coronavirus, but if you suspect you have it, isolate yourself at home.
Many patients with coronavirus are able to recover at home. If you’ve been diagnosed and your illness is worsening, seek medical attention promptly. You may need to be monitored in a hospital.
No. Those products work on surfaces but can be dangerous to your body.
There are some chemical disinfectants, including bleach, 75% ethanol, peracetic acid and chloroform, that may kill the virus on surfaces.
But if the virus is already in your body, putting those substances on your skin or under your nose won’t kill it, the World Health Organization says. And those chemicals can harm you.
There’s no evidence from the outbreak that eating garlic, sipping water every 15 minutes or taking vitamin C will protect people from the new coronavirus. Same goes for using essential oils or colloidal silver.
Some people with coronavirus have mild or no symptoms. And in some cases, symptoms don’t appear until up to 14 days after infection.
During that incubation period, it’s possible to get coronavirus from someone with no symptoms. It’s also possible you may have coronavirus without feeling sick and are accidentally infecting others.
Experts said cuts in federal funding for public health and problems with early testing forced the US to play catch-up.
Problems with public health infrastructure: Two years ago, the CDC stopped funding epidemic prevention activities in 39 countries, including China. This happened because the Trump administration refused to allocate money to a program that started during the 2014 Ebola outbreak.
Former CDC director Dr. Tom Frieden warned that move “would significantly increase the chance an epidemic will spread without our knowledge and endanger lives in our country and around the world.”
Problems with the testing: Malfunctions, shortages and delays in availability have all contributed to the slowdown.
In the first few weeks of the outbreak in the US, the CDC was the only facility in the country that could confirm test results — even though a World Health Organization test became available around the same time.
Some test kits that were sent around the country were flawed — a move that put the US behind about “four to five weeks,” says Dr. Rob Davidson, executive director of the Committee to Protect Medicare.
No. There are some interesting coincidences in the 1981 fiction novel, which says “a severe pneumonia-like illness will spread around the globe” around the year 2020. Modern editions of the book call the biological strain “Wuhan-400,” and the current coronavirus outbreak started in Wuhan, China.
But there are important differences between the book and reality. The original version of the book called the strain the “Gorki-400,” in reference to a Russian locality, before it was later changed to the “Wuhan-400.” In the book, the virus was man-made, while scientists believe the novel coronavirus started in animals and jumped to humans. And in the book, the virus had a 100% mortality rate. Early estimates of the mortality rate for this coronavirus outbreak range from 2-4%.