Daily coronavirus cases have dropped to pre-Thanksgiving levels, but U.S. officials are terrified of variants that swamped British hospitals and might weaken available weapons against the disease, turning the vaccine effort into a frantic dash to keep the virus from replicating and mutating further.
The country is counting fewer than 150,000 cases per day, on average, a level not seen since mid-November, but scientists say any let-up in the effort will give the virus enough space to evolve in ways that make the pandemic fight steeper and longer.
“Thousands of Americans continue to die each day from COVID-19, while new, more contagious strains are emerging in the United States. We are now in a race to keep vaccines ahead of new virus variants — and the stakes could not be higher,” House Energy and Commerce Chairman Frank Pallone Jr., New Jersey Democrat, said Tuesday.
The U.S. has delivered more than 32 million vaccine doses into arms and is administering 1.3 million doses per day, on average, though a rising share of doses will be given to people as second-round shots instead of increasing the number of people receiving first-round protection. Experts and critics of President Biden say the Trump administration handed him a program that was at or near his early goal of 1 million doses per day, so Washington should find a way to scale up to 3 million doses per day.
The White House announced incremental progress Tuesday. The weekly allocation of vaccines will increase 5% in the coming week, to 10.5 million from 10 million, because of increased production from makers Pfizer-BioNTech and Moderna.
It’s the second increase from the White House in as many weeks, but other plans should have a bigger impact, from regulatory review and approval of Johnson & Johnson’s one-dose vaccine to a push by Moderna to put 15 doses in each of its vials instead of 10. It is discussing the plan with the Food and Drug Administration.
They’re racing against a fast-moving “U.K. strain” that has reached at least 32 states, making it the most prevalent of new, powerful strains circulating across the globe. It could become the dominant version in the U.S. within weeks, federal officials say.
The strain is up to 40% more transmissible and might be deadlier, studies show, though the vaccines appear to work pretty well against it. That’s a bright spot, though British scientists recently detected 11 instances of a “E484K mutation” that could diminish the vaccines’ power.
Calum Semple, an adviser to the British government, told BBC radio that E484K was the “mutation of most concern” and had “occurred spontaneously.”
The mutation is similar to ones on variants first detected in Brazil and South Africa, sparking fears the virus will find ways to evade vaccines and antibody treatments.
Scientists are trying to find out why the mutation occurs, though it could be the result of the virus finding new ways to burn through societies.
“It appears the E484 is arising in situations where possibly there are enough individuals immune from prior infection to put a Darwinian selection pressure on the virus,” said Amesh Adalja, a senior scholar at the Johns Hopkins Center for Health Security. “This mutation may be what results. It will be important to actually confirm this by sequencing viruses and studying the epidemiology and clinical history from those possibly reinfected in South Africa and in Brazil.”
The South Africa strain has been detected in two states — three cases in Maryland and two in South Carolina. A single case of the P.1 variant, or “Brazil” strain, has been detected in Minnesota.
Nearly 500 cases of the U.K. strain have been found, though the U.S. government hasn’t been sequencing enough samples to see how prevalent it is. Federal disease-trackers are trying to increase their surveillance, as the Biden administration extends travel restrictions on places such as Brazil, South Africa and much of Europe to try to keep new cases out.
“They will be in place as long as our health or medical experts believe they’re necessary, or essential, in order to keep the public safe,” White House press secretary Jen Psaki said Tuesday.
The Pfizer and Moderna vaccines appear to provide an adequate “cushion” of protection against the worrisome strains, but the South Africa one diminished the level of certain antibodies, prompting the companies to explore booster shots tailored to the strain.
Johnson & Johnson said its one-dose vaccine staved off serious disease in South Africa but its shot was less effective in stiff-arming moderate-to-severe disease than in other trial locations, at 57% compared to 72% in the U.S.
Scientists caution that vaccines produce a variety of antibodies and the emerging strains have multiple features, such as the “N501Y” mutation in addition to E484K, so more study is needed.
“It is reasonable to think [E484K] might diminish efficacy by a bit, but that’s not a ‘vaccine escape mutation’ by any stretch of the imagination,” said William Hanage, an associate professor of epidemiology at the Harvard T.H. Chan School of Public Health.
Yet scientists fear that over time, the emerging strains will mutate in ways that make them even stronger, complicating the pandemic fight that upended normal life and economies over the past year.
Dr. Anthony Fauci and other scientists have characterized the mutations as a “wake-up call” for the world as government officials and health professionals seek ways to vaccine people faster and control the virus.
“Each infection is an opportunity for the virus to mutate,” Dr. Hanage said. “And while the vast majority of mutations don’t matter, if you allow a huge number of infections, it increases the chance of a mutation which does matter.”