As Covid-19 cases begin surging again, drugmakers are racing to develop next-generation vaccines, which, according to White House Covid-19 coordinator Ashish Jha, "are going to provide a much, much higher degree of protection against the virus that we will encounter in the fall and winter."

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Covid-19 cases surge

Covid-19 cases have started rising across the United States, with CDC reporting 98,000 new cases last Tuesday. But experts say the true number of new Covid-19 cases is likely higher than reported, given the rise of at-home Covid-19 tests, the results of which often aren't reported to health officials.

"There's so much less visibility about what's happening," said Rick Bright, a virologist and CEO of the Rockefeller Foundation's Pandemic Prevention Institute.

"Our ability to detect [coronavirus variants] is being substantially hindered because testing rates have plummeted, and in doing so, our sequencing rates have plummeted as well," said Maria Van Kerkhove, technical lead for Covid-19 at the World Health Organization.

Hospitalizations are also rising, increasing 20% over the past two weeks, according to CDC.

"The reality is that things are really not going well at the moment," said Jacob Lemieux, an infectious disease doctor at Massachusetts General Hospital. "We all thought that we were in for a reprieve after the devastating omicron wave. And that was clearly the case until a few weeks ago."

However, David Dowdy, an epidemiologist at Johns Hopkins' Bloomberg School of Public Health, said he believes that even if cases continue to rise, hospitalization and death rates will remain relatively low.

"In some ways, this is encouraging, in that we're starting to see a divergence between the number of cases and the number of hospitalizations and deaths," he said. "But it's also a little bit discouraging that we've been through all this and we're still seeing a flat line and an uptick in the number of people getting admitted to the hospital and in people dying."

The rise in cases is largely driven by reinfections, data shows. The Colorado State Health Department has reported 44,000 reinfections during the pandemic, 82% of which have occurred since December when omicron became the dominant variant. Similarly, Indiana has reported that 12% of its total cases in the first quarter of 2022 have been reinfections while 18.5% of total cases in Idaho during that same period have been reinfections.

Research has found that Covid-19 reinfection is more likely with omicron, and that the variant shortens how long previous infection protects a person from the coronavirus. Another study, which has not been peer-reviewed, found that the BA.2.12.1, BA.4, and BA.5 omicron subvariants are able to evade the immunity defenses provided by infection with BA.1, a different omicron subvariant.

"It feels like the first time in two years that no matter if someone is really careful and does everything right, it won't be surprising if they end up getting Covid," said Bob Wachter, chief of medicine at the University of California, San Francisco. "We're unquestionably in a surge."

Drugmakers start developing a vaccine for the fall

As cases rise across the United States, Peter Marks, director of FDA's Center of Biologics Evaluation and Research, acknowledged there is a "very compressed time frame" in which experts will need to determine what a new Covid-19 vaccine for the fall will look like, likely by the end of June.

Similarly, Jha said that this fall, Americans are going to be much more vulnerable to Covid-19 and will need a new vaccine.

"As we get to the fall, we are all going to have a lot more vulnerability to a virus that has a lot more immune escape than even it does today and certainly than it did six months ago," he said. "That leaves a lot of us vulnerable."

Jha added that he believes the next generation of vaccines—which are likely to be based on the omicron variant—"are going to provide a much, much higher degree of protection against the virus that we will encounter in the fall and winter."

But according to Allie Greaney, who studies the dynamic between viruses and the immune system at the University of Washington and the Fred Hutchinson Cancer Center, whatever version of the coronavirus drugmakers use for the next set of vaccines is "probably going to be the wrong one" because of how quickly the virus changes.

In order to create the upcoming season's flu shot, "we do surveillance; we figure out what to be prepared for," said Adam Lauring, a virologist at the University of Michigan. But with the coronavirus, "the dynamics are still so wacky." Surges rise and fall in different areas of the world every few months and new variants and subvariants continue to arrive quickly.

Even still, a new vaccine based on omicron is likely to provide better defenses than previous doses of the vaccine, said Marion Pepper, an immunologist at the University of Washington.

"Boosting with Omicron will almost certainly provide more immunity against currently circulating strains," said Taia Wang, an immunologist at Stanford University.

Regardless of how the next Covid-19 vaccine is designed, many experts agreed that doing nothing would be the worst possible decision. "We're always playing catch-up," said Karthik Gangavarapu, a computational biologist at the University of California, Los Angeles. "But if we don't do anything, we're for sure not going to be able to win the race." (Muller, Bloomberg, 5/13; Joseph, STAT News, 5/12; Wu, The Atlantic, 5/13; Miller, Associated Press, 5/12)