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After more than two months of sharp decline, coronavirus infections are on the rise again nationwide – along with COVID-19 hospitalizations in many countries.
Over the past seven days, the United States has reported an average of just over 65,000 new cases a day, up 20 percent from two weeks earlier. Many states have seen even more dramatic growth, reaching 125% in Michigan, according to an NPR analysis of data from Johns Hopkins University.
And hospitalizations have increased for seven consecutive days in more than a dozen states, mostly in the Midwest and Northeast, according to the University of Minnesota Hospitalization Tracking Project COVID-19.
All of these signs point to a growing threat of another significant jump in COVID-19 cases, experts say.
But there is cautious optimism that it is unlikely to be as devastating as the previous wave, which saw 200,000 or more confirmed cases a day for most of December and early January, according to data tracked by Johns Hopkins University.
“Thanks to the rapid release of vaccines, I don’t think we’re going to have a jump like we’ve seen before,” said Jennifer Nutzo, an epidemiologist and senior scientist at the John Hopkins Center for Health Security. “However, any additional deaths at this time are a tragedy, given that we have vaccines on hand that could prevent them.”
What stimulates the growth of infections?
Another leap is inevitable, says epidemiologist Bill Hanaj of Chan’s Harvard School of Public Health. But he added that “it may not be national, not all at once, and the consequences will vary depending on how many people are vaccinated when it starts.”
In fact, the increase in cases so far has not been consistent across the country. The Midwest has seen a 58% increase in new cases in the last 14 days, while the number of cases in the Northeast has increased by 30%. Cases in the West have risen by 5%, while in the South there is a slight decline.
In total, 33 states and the District of Columbia have an increasing number of cases, with seven states (plus Puerto Rico) increasing by more than 50%.
A number of factors fuel the revival. States are easing restrictions, while pandemic fatigue has led to less vigilance over precautions such as wearing masks, social distancing and hand washing.
Perhaps the biggest unknown is how the rapid spread of a coronavirus strain can develop.
The highly contagious variant B.1.1.7 represents a growing proportion of cases in the United States and is likely to lead to the current increase, Hanaj said. The strain, which appeared in the United Kingdom, is up to 50% more contagious and new research shows that it is more likely to cause serious illness and death.
Hospitalizations are another sign of how the rise in waves is increasing. Growth in the last week or so is the first time since the winter tide that hospitalizations appear to be increasing: 10 countries have had jumps of 10% or more; four states – Michigan, South Dakota, Connecticut and Maryland – have increased by about 15% or more, according to a project to track hospitalization at the University of Minnesota.
“A matter of choice”
So far, there are still plenty of reasons for hope. The vaccine is spreading rapidly, albeit unevenly. So far, about 17% of adults in the United States have been fully vaccinated.
And vaccines appear to be effective in preventing serious disease and death from all currently circulating strains, including option B.1.1.7, Hanage told NPR’s All Things Considered. So this is a race to vaccinate people before the rapidly spreading option takes power.
There are two other positive factors to consider: warming weather and existing immunity to previous infections, says Natalie Dean, a biostatistician at the University of Florida.
The fact that many people have been infected naturally – during the last tide and even earlier – “will help eliminate some of what could potentially happen in the future,” she explains. “And the fact that we’re coming out of the winter months into the spring, all of these things work in our favor.”
However, Harvard epidemiologist Harnage notes that it is important to pay attention to high-risk groups that may not be vaccinated so quickly.
“It does not take a large number of infections in the most vulnerable groups to cause serious problems,” he told NPR.
NPR researchers spoke to anyone who warned that American public policy and behavior could still make a huge difference in how bad the next wave would be.
Alessandro Vespignani, a disease modeler at Northeastern University in Boston, warns that relaxing measures such as social distancing can now turn this into a bigger surge. Instead, he says, we need more time to run the vaccination campaign.
“We really have to keep fighting for a few weeks,” he said. “We see this light at the end of the tunnel and it’s a matter of holding things back for a few more weeks. It’s a matter of choice at this point.”
How long will this jump last?
Ashish Ja, dean of Brown University’s School of Public Health, says he is concerned about the next four to six weeks, but expects that “once we move to May, things will stabilize and start to improve.”
The COVID-19 prediction team at the Children’s Hospital of Philadelphia’s PolicyLab says they see signs that the new jump will not be as long as the winter one. In a forecast update this week, they predict that cases in several Michigan cities may soon reach a spring peak and predict that the New York region may also stabilize.
Other experts say the tide could last until June and is likely to be quite severe.
Nicholas Reich, an epidemiologist at the University of Massachusetts, Amhurst, said he would “be surprised but not shocked” if the surge actually rose to levels seen in the winter. At the moment, he says, Michigan is at least “moving in that direction at an alarming rate.”
Although this revival of COVID-19 is not usually expected to be as bad as the winter wave, experts have repeatedly insisted that now is not the time to relax.
Earlier this week, CDC Director Dr Rochelle Valensky said that despite the positive momentum, she described the feeling of “impending doom” as the number of cases rose.
“It will be crucial for people to commit to masking and keeping meetings small to protect communities in the coming weeks,” said Lauren Wells, director of strategic operations and communications at Children’s Hospital of Philadelphia, PolicyLab.
Melissa Nolan, a professor of epidemiology at the Arnold School of Public Health at the University of South Carolina, says the current boom could actually be followed by another flare-up this summer.
“Our models offer June as another peak, approximately a quarter of the size of last summer,” she says, resulting in adults and children remaining unvaccinated.
In fact, the trajectory and duration of the wave will depend a lot on how quickly people get vaccinated and what Americans do – and their states and local governments in the meantime.