04:07 - Source: CNN
Scientist explains how they're creating a universal Covid vaccine
CNN  — 

The much-awaited summer lull in coronavirus cases doesn’t appear to be happening as Covid-19 infections continue to increase in much of the United States.

An earlier rise in cases this year was driven by the BA.2 Omicron subvariant. Now, the US Centers for Disease Control and Prevention reports that two other subvariants, BA.4 and BA.5, constitute more than 70% of new infections in the country. These subvariants may partially escape the immunity produced by the vaccine and by prior infection, though vaccination still likely protects against severe illness.

These developments are occurring as more people resume travel and other pre-pandemic activities. How should people think about their risk from Covid-19 right now? If they are vaccinated and boosted, are they safe? What about those who recently had Covid-19? What kind of precautions should people take if they still want to avoid Covid-19? And if someone tests positive for the coronavirus, should this person still isolate?

To help with these questions, I spoke with CNN Medical Analyst Dr. Leana Wen, an emergency physician and professor of health policy and management at the George Washington University Milken Institute School of Public Health. She is also author of “Lifelines: A Doctor’s Journey in the Fight for Public Health.

CNN: Do current Covid-19 trends indicate that there is another surge of cases in the United States?

Dr. Leana Wen: I’m not sure this would be called another surge because the numbers didn’t really come down from the previous rise. In the winter, from December 2021 to about February 2022, we saw a huge surge in cases from the original Omicron subvariant, BA.1. There was a small lull; then BA.2 came along with that rise in cases. Now, BA.4 and BA.5 are displacing previous Omicron subvariants and are causing most of the infections in the US. Many places are seeing an increase in infections from a high baseline of cases.

We also have to keep in mind that the number of reported cases is much lower than the actual number of cases. I think we could have anywhere from five to 10 times as many cases as are reported, considering how many cases are diagnosed by home antigen tests and are not reported to public health authorities.

The good news is that these recent surges have not been accompanied by hospitals being overwhelmed, which illustrates the powerful effect of the vaccines in mostly decoupling infection from severe illness.

CNN: With these kinds of numbers, how should people think about their Covid-19 risk? Does that mean people should cancel travel and bring back restrictions?

Wen: I don’t think that most people should have to change their daily activities, but I do think people need to be aware of their risk of contracting Covid-19 if they don’t take additional precautions.

The good news is that the vaccines and boosters continue to provide excellent protection against severe disease. However, we also know that immunity wanes over time, and there does appear to be some immune (evasion) with BA.4 and BA.5 in particular. That means people who are vaccinated and boosted are unlikely to become severely ill if they contract Covid-19, but they could still become infected.

Some commuters don masks in New York's Times Square subway station last week.

The question people should ask is this: How much do they want to continue to avoid infection? There is so much virus around us, and the variants are so contagious. That means avoiding infection requires additional consideration. Many people may not want to plan their lives around Covid-19 precautions anymore, especially if they are generally healthy and well-protected from severe illness.

On the other hand, many people may still prioritize not contracting Covid-19 because of the risk of long-haul symptoms. They may also have underlying medical conditions that predispose to more severe outcomes themselves, or they may live with others who are more vulnerable and want to reduce their risk to those around them.

CNN: For people who want to be cautious, what do you recommend?

Wen: For individuals who want to prioritize reducing their risk of Covid-19 infection, I’d advise first that they follow the CDC guidance and stay up to date on their boosters. Everyone ages 5 and older can receive a first booster. Those 50 and older can receive a second booster for a total of four shots.

Certain individuals (who are moderately or severely immunocompromised) can receive five shots. (These individuals should also find out if they are eligible for Evusheld, the preventive antibody that can further aid in reducing the progression to severe illness.)

I’d also urge that they wear a high-quality N95 mask or equivalent in indoor, crowded settings. Mask mandates being lifted does not mean that people shouldn’t wear masks. A lot of people don’t find masks to be inconvenient. If that’s the case, I’d continue to wear masks in all indoor public settings. For those who find masks uncomfortable, I’d encourage mask-wearing in the highest-risk settings – for example, mask while in a crowded security line at the airport and during boarding and deplaning.

Of course, remember that outdoor gatherings continue to be much lower risk than indoors. People who want to be very cautious should try to go to outdoor gatherings if possible and then go to indoor gatherings only if others all have negative tests that day.

CNN: A lot of people are sick of hearing about these precautions. What if they just want to live their lives but don’t want to infect vulnerable people?

Wen: I certainly understand this sentiment. It’s very hard for society to impose restrictions on individuals and ask people to forever put gatherings like weddings and birthday parties on hold or to forgo going to activities they love like indoor restaurants and gyms. My best advice here is to recognize that if you go to indoor settings, you could contract Covid-19. Be aware of your risk and take precautions accordingly.

For example, perhaps you can go about living your life as you wish, but before you visit grandma in a nursing home, take a rapid test that day. If you go to a crowded indoor wedding, take a test a few days after to make sure you didn’t contract the coronavirus. And if you have symptoms at any point, immediately test and do not expose others around you.

CNN: Are you safe if you recently had Covid-19?

Wen: Recent infection produces some protection that probably lasts for about three months. Reinfection can certainly happen though, and some studies suggest that getting the original Omicron BA.1 does not protect against the newer variants. Vaccination in addition to recent recovery conveys better protection, so make sure you are up to date with your vaccines and boosters, even if you’ve had Covid-19.

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CNN: And what if you do test positive – should you still isolate?

Wen: Yes, because you don’t want to spread Covid-19 to others. The CDC guidance is that you isolate for five days and then wear a mask around others for an additional five days after that if symptoms are improving. I think a testing policy is even better than this because people remain infected for different lengths of time. I’d encourage people to take home tests daily from day four and to end isolation once their home rapid antigen test is negative. Now is the time to make sure you have plenty of home tests!