Variants Spreading in U.S. Fan the Need to ‘Crush’ Covid Quickly
A Covid-19 mutation that likely confers partial resistance to the antibodies produced by vaccines is now in the U.S., spurring scientists to probe new ways to battle a disease that’s constantly changing and could remain active for years.
The South African variant has already spread quickly across the African continent and has been seen in at least 24 countries outside of Africa. It was reported in South Carolina on Jan. 28 and in Maryland two days later. If that looks like just a beachhead, note that a U.K. mutation first seen in Colorado on Dec. 29 has been detected in 29 U.S. states in less than a month. Both variants are considered more contagious than the original strain.
Late-stage trials released last week on vaccines developed by Johnson & Johnson and Novavax Inc. showed their shots to be generally potent against early forms of Covid-19. But results from studies done in South Africa told a less impressive tale. The J&J shot was found to be 72% effective in the U.S., but that fell to 57% in South Africa. Novavax’s shot, 89% effective in the U.K., was only 49% effective in South Africa.
The results are “sobering,” said Eric Topol, director of the Scripps Research Translational Institute in San Diego. “We see an unequivocal drop-off in efficacy.”
That means that vaccine makers must now divert attention to work on either booster shots or a new, adjusted vaccine that can work better against the South African mutation, known scientifically as B.1.351, even as the world is ramping up injections of the first shots put into use, he said.
“We are having enough of a struggle getting the first round of vaccines in,” Topol said.
Before the J&J and Novavax results were made public, lab tests looking at the number of antibodies induced by vaccines from Pfizer Inc. and Moderna Inc. already in use suggest that while they may be less potent against the South African variant, they still had enough punch to hold it off.
But what that meant in terms of illness in the real world was unclear. The latest outcomes offer a more precise indication, said Anthony Fauci, the top U.S. infectious disease expert, on a conference call on Friday.
“It’s really a wake up call for us to be nimble, and to be able to adjust as this virus will continue for certain to evolve and to mutate,” he said. “Now we have the real-world clinical consequences, and we can see that we are going to be challenged.”
In statements at the New York Press Club on Friday, Fauci said it was “concerning that you need to stay ahead of these mutants, and essentially crush this outbreak so there’s no more replication. And when there’s no more replication, you’re not going to have any mutations.”
In laboratory results reported before the new Novavax and J&J trial data was in, scientists from the Aaron Diamond AIDS Research Center at Columbia University found that the Pfizer and Moderna vaccines were 6.5 to 8.6-fold less potent against the South African mutation.
100 Million Chances
“Looking at our results you cannot say this would doom the vaccine. That would be wrong,” said David Ho, who leads the lab. “But I think it is equally wrong to say everything is rosy.”
The world has “allowed the virus to infect 100 million people already,” he said. “So that is 100 million chances for mutation.”
The late-stage trials reported last week by J&J and Novavax could potentially pave the way for them to be authorized for use. J&J’s vaccine offers users a single shot regimen, as opposed to the two-dose versions authorized for Pfizer and Moderna. The drug giant plans to file this week with the U.S. Food and Drug Administration for an emergency-use authorization, company officials said. J&J’s top scientist said this month he expects clearance in March.
The Novavax shot, meanwhile, is likely to get its first approval in the U.K., and the company is discussing with U.S. regulators whether trial data from other countries could be part of the shot’s review, Chief Executive Officer Stan Erck said. Novavax is still recruiting patients for a trial in the U.S. and Mexico, Erck said in an interview on Bloomberg Television.
Still, Pfizer, Moderna and J&J have all said they’re starting work on developing booster shots or other approaches to buttress their vaccines. It remains unclear how long the shots will immunize people against Covid-19, and new mutations may require changes in their makeup.
For the U.S., the first important step is to know when mutations are around. In another Friday briefing, Centers for Disease Control and Prevention Director Rochelle Walensky said the U.S. has now asked each state to send at least 750 samples a week to be sequenced to determine what variants may be here and how widely they may be spreading.
She warned that the existing U.S. system to detect different mutations is too slow for public health interventions to contain them.
“By the time someone has symptoms, gets a test, has a positive result and we get the sequence, our opportunity for doing real case control and contact tracing is largely gone,” Walensky said. “We should be treating every case as if it’s a variant during this pandemic right now.”
While nations worldwide, including the U.S., are seeking to contain the spread of the variants with travel restrictions, history suggests that’s a near impossibility.
Meanwhile, Peter Marks, director of the FDA’s Center for Biologics Evaluation and Research, said the agency is seeking to finalize a playbook with the industry to address mutations.
If the agency feels the virus has drifted enough to require a different sequence, it will require small trials to make sure the vaccines produce an immune response, he said. The first few studies may have to go through an advisory committee, according to Marks, but the agency is looking to streamline the process as much as possible and may require less data over time.
“We would intend to be pretty nimble with this,” Marks said on an American Medical Association webinar, “so we get these variants covered as quickly as possible because it is clear they can spread pretty quickly.”
The bottom line from scientists: This is a fight that could go for a long time.
Vaccines that work well now may fade in the future unless strong booster shots are devised. And it could be that Covid-19 morphs into something akin to influenza, requiring periodic booster shots over the years to keep it at bay.
“The implications are really worrisome,” said Peter Hotez, the dean of the National School of Tropical Medicine at Baylor College of Medicine, in an interview Thursday after the Novavax results were announced. “All the vaccine makers now have to make decisions” on how to proceed.
In the meantime, it’s now a race to vaccinate the U.S. and Europe before the South Africa variant becomes more common or, worse yet, new mutations develop that make the virus more resistant.
In his New York Press Club comments, Fauci was asked what keeps him up at night. His answer: “A mutant, where it really escapes everything.”
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