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At least 21 states have recorded at least a 10% rise in daily average positive cases of Covid-19, according to Johns Hopkins University data Thursday, demonstrating that the fight against the pandemic is far from over.

In Michigan, hospitals are increasingly overwhelmed and reaching full capacities in part due to the influx of new coronavirus cases. State and local officials across the country are attempting to avoid a similar situation and are pushing to increase vaccination levels among adults, which shows continuing signs of improvement.

More than 30% of US adults have been fully vaccinated, according to the most recent data from the Centers for Disease Control and Prevention (CDC), and a CNN analysis has some states being able to vaccinate all willing adults by June.

However, between varying rates of vaccine hesitancy and the pace of vaccinations, the timeline for vaccinating all willing adults varies greatly among states – a growing concern because, for some locations, a new surge may have arrived.

“We have knocked down this virus already three times, but we have to knock it down a fourth time,” Washington Gov. Jay Inslee said Thursday, as the state’s infection numbers have turned upwards again.

Modelers predict little improvement in fight to slow pandemic

An influential team that makes regular forecasts about the course of the pandemic sees little progress this week in preventing future deaths.

The Institute for Health Metrics and Evaluation at the University of Washington warns that declining vaccine confidence combined with eased restrictions could give the virus the opportunity to surge again.

“In our reference scenario, which represents what we think is most likely to happen, our model projects 618,000 cumulative deaths on August 1, 2021. This represents 58,000 additional deaths from April 12 to August 1,” the IHME said in its latest forecast. That’s almost the same as last week’s forecast.

“If universal mask coverage (95%) were attained in the next week, our model projects 13,000 fewer cumulative deaths,” they added.

But the model instead foresees people dropping mask use. “The trend toward mandate easing continues, and it appears quite possible there will be a huge behavioral rebound,” the IHME said.

The IHME says although cases are up, deaths are down.

“The slow national increase in cases and hospitalizations and decline in deaths despite widespread B.1.1.7 circulation may be due to three factors: higher past levels of infection in the US compared to Europe, higher vaccination rates on average than in Europe, and the arrival of B.1.1.7 after the peak of winter seasonality,” the IHME said.

Under a worst-case scenario, 679,000 people will have died by August 1 if more people stop wearing masks and start moving around and gathering more, they say.

Measures to prevent new surge

In order to prevent a new surge as well as Covid-19 variants that may be more infectious, health experts continue to recommend mask-wearing, social distancing, and above all else, vaccination.

“The vaccines have saved thousands of lives already,” Emory University executive associate dean of medicine Dr. Carlos del Rio told CNN. “We’ve seen mortality in the US decline despite cases going up, and that’s because we’re vaccinating people.”

Dr. Kawsar Talaat, an infectious disease physician and assistant professor at Johns Hopkins Bloomberg School of Public Health, told CNN on Thursday that while CDC data has shown that vaccines cannot fully prevent all Covid-19 infections, such “breakout” cases are rare. Widespread vaccination means that less virus is circulating and there is less opportunity for exposure.

“That’s the whole point of getting to herd immunity,” Talaat said. “Because once we get to a point where enough people in the community are vaccinated, then if somebody develops Covid in that community, the people around them are protected and it’s much harder for that person to spread the virus to somebody else, and therefore the transmission stops.”

While more than 78% of those ages 75 and up have received at least one dose of vaccine, the percentage of those vaccinated ages 18-29 is at roughly 25%, CDC data shows. And young and relatively healthy people who have had Covid-19 before should still get a vaccine to prevent reinfection, according to research published Thursday in the journal Lancet Respiratory Medicine.

The effect of rising infection rates is being felt on a local level. Ohio Gov. Mike DeWine said Thursday that although more than 36% of residents have received at least one dose of vaccine, hospitalizations are increasing.

“It’s a lagging indicator, so not a direction that we want to be going,” DeWine said.

“We just have to keep going,” DeWine said. “We know how to get out of this. You know, this is not five months ago, four months ago, we know how to get out of this, and we have the tool to get out of it. We just have to use the tool and we’ve got to use it every day. And that is vaccinate.”

States push to get ahead of rising infections

Nationwide, states are racing to inoculate as many residents as possible.

“We know that these vaccines are really responsible primarily for the 90% reduction in deaths we’ve seen over the first 13 weeks of 2021,” Dr. Clay Marsh, West Virginia’s Covid-19 czar, said Thursday.

Aware that transportation can be a barrier for some, Rhode Island announced that free public transit trips to and from vaccination appointments will be available starting Monday.

“This is a big win for Rhode Island’s vaccination efforts,” said Governor Dan McKee. “I hope that no-cost trips will enable everyone who wants to get to a vaccine clinic to get there easily.”

News coming out of several states was cautiously optimistic, as Pennsylvania, Kentucky, Connecticut and Georgia all highlighted increases in vaccination numbers.

New York reported its lowest number of hospitalizations since December 1 and that more than half of New York adults had received at least one dose of a vaccine, according to Gov. Andrew Cuomo’s office.

Citing a 95% drop in the daily average of deaths in the state, New Hampshire Gov. Chris Sununu announced that a mask mandate set to expire Friday will not be renewed.

“The lifting of the mandate does not diminish the importance of wearing a face mask,” Sununu said, noting that numbers remain high across the state. “We ask that people continue to take steps to protect their own health, the health of their family and friends, and the health of their community.”

Johnson & Johnson vaccine side effects are investigated

As vaccine distribution continues, the Johnson & Johnson vaccine remains paused.

A severe form of blood clot in the brain known as cerebral venous sinus thrombosis (CVST) may be linked to the vaccine, yet the occurrence rate is rare. So far, only six cases have been reported in the US out of the approximately 7 million doses administered to date. One person died and another is in critical condition, an FDA official said Tuesday.

One of the six cases involved a 26-year-old Pennsylvania woman, according to the state’s department of health, who recovered after receiving treatment at a hospital. The state, which is pausing J&J distribution until April 24, said that federal oversight of vaccine safety is functioning as intended.

“The safety procedures built into the vaccination process are working and should instill confidence in the safety and effectiveness of the available Covid-19 vaccines,” Pennsylvania Acting Secretary of Health Alison Beam said. “I urge individuals who have appointments scheduled to receive a Pfizer or Moderna vaccination to keep those appointments.”

After the CDC and the US Food and Drug Administration recommended a pause on Tuesday, the CDC’s Advisory Committee on Immunization Practices met Wednesday without voting on taking any further action, stating that more information is needed, and vaccine advisers to the CDC have scheduled a meeting for April 23 to determine whether additional intervention is required.

“Hopefully, we’ll get a decision quite soon as to whether or not we can get back on track with this very effective vaccine,” Dr. Anthony Fauci told a Congressional hearing Thursday.

ER technicians test patients for Covid-19 outside of the emergency entrance of Beaumont Hospital in Grosse Pointe, Michigan, on Thursday.

In response, Johnson & Johnson decided to pause vaccinations in all of its clinical trials while the company updates “guidance for investigators and participants,” according to a news release posted Tuesday afternoon.

Recipients of the vaccine who develop severe headache, abdominal pain, leg pain, or shortness of breath within three weeks after vaccination should contact their health care provider, the CDC and FDA said.

For those that received the J&J vaccine more than a month ago, the risk is “very low,” said CDC principal deputy director Dr. Anne Schuchat during a virtual briefing on Tuesday.

CNN’s Ben Tinker, Maggie Fox, Deidre McPhillips, Naomi Thomas, Amanda Sealy, Sandee LaMotte, Jen Christensen, Kristina Sgueglia, Juliana Battaglia, Rebekah Riess, Andy Rose, Jacqueline Howard, Virginia Langmaid, Melissa Alonso, Lauren Mascarenhas and Nadia Kounang contributed to this report.