For weeks, New Yorkers have witnessed the alarming rise of a homegrown variant of the coronavirus that has kept the number of cases stubbornly high in the city. City officials have repeatedly warned that the variant could be more contagious and could dodge the immune response.
On that second point, at least, they can now breathe easier: Both Pfizer-BioNTech and Moderna vaccines will effectively prevent serious illness and death from the variant, two independent studies suggest.
Both studies found that the antibodies stimulated by these vaccines are only slightly less potent in controlling the variant than the original form of the virus.
“We don’t see big differences,” said Michel Nussenzweig, an immunologist at Rockefeller University in New York and a member of the team that published one of the studies on Thursday.
The bottom line? “Get vaccinated,” he said.
The findings are based on laboratory experiments with blood samples from a small number of vaccinated people and have not yet been peer reviewed. However, they are consistent with what is known about similar variants, several experts said, and add to a growing body of research suggesting that the two leading vaccines in the United States are protective against all variants identified so far.
“The take-home message is that the vaccines will work against the New York variant and the South African and British variant,” said Nathan Landau, a virologist at NYU’s Grossman School of Medicine who led the study.
Vaccines stimulate the body to develop an expansive immune response, with thousands of types of antibodies and different types of immune cells. A subset of these immune fighters, called neutralizing antibodies, are essential to prevent infection. But even when neutralizing antibodies are scarce or absent, the rest of the immune system can deploy sufficient defense to ward off serious illness and death.
In both new studies, the neutralizing antibodies of vaccinated people were more effective at fighting the virus than those of people who developed antibodies for being sick with Covid-19. Direct comparison of the two antibody sets offered a possible explanation: the antibodies from vaccinated people are distributed across a wider range of parts of the virus, so no single mutation has a large impact on their effectiveness, making vaccines a better bet against. the variants with respect to immunity from natural infection.
The variant first identified in New York, known to scientists as B.1.526, made its way through the city after its initial discovery in November. It represented one in four cases diagnosed in November and nearly half of the cases as of April 13. The variant that brought Britain to a standstill, B.1.1.7, is also circulating widely in New York. Together, the two account for more than 70% of coronavirus cases in the city.
Concern for the variant identified in New York has centered on one form of it, which contains a mutation that scientists refer to as Eek. The Eek mutation subtly alters the shape of the virus, making it difficult for antibodies to target the virus and, consequently, undermining vaccines.
In the second study, Dr Landau’s team found that Pfizer and Moderna vaccines are only marginally less protective against the variant that devastated Britain and against forms of the variant discovered in New York that do not contain the Eek mutation.
Several laboratory studies have shown that the antibodies induced by Pfizer and Moderna vaccines are slightly less potent against a third variant, the one identified in South Africa, which also contains Eek. Other vaccines fared worse. South Africa suspended the use of the AstraZeneca vaccine after clinical studies showed that the vaccine does not prevent mild or moderate disease from the variant circulating there.
“It has already started as a lower level in terms of the immunity it generated,” said Dr Nussenzweig of the AstraZeneca vaccine. Referring to the shots from Pfizer and Moderna, he said: “We are so lucky in this country to have these vaccines compared to the rest of the world.”
Florian Krammer, an immunologist at the Mount Sinai Icahn School of Medicine who wasn’t involved in any of the new studies, said he was more concerned about other countries’ vaccination programs than the variants themselves.
“I’m less worried about the variants than I was two months ago,” he said, but added, “I’m worried about countries that don’t have enough vaccines and that don’t have the vaccine launch. I’m no longer worried about the United States. honestly. “
Dr Landau’s team also tested monoclonal antibodies used to treat Covid-19 against the variants. They found that Regeneron’s cocktail of monoclonal antibodies also worked against the variant discovered in New York and the original virus.
The studies are reassuring, but they indicate that the Eek mutation is worth watching, said Jesse Bloom, an evolutionary biologist at the Fred Hutchinson Cancer Research Center in Seattle.
“This could certainly be a step towards the virus becoming a little more resistant to infections and vaccine-mediated immunity,” said Dr. Bloom. “I don’t think it’s something people need to be alarmed about immediately, but it certainly strikes us as important.”
Dr. Bloom conducted the analysis by comparing the vaccine-induced antibodies with those produced by natural infection. He found that the strongest antibodies bind to multiple sites in a key part of the virus. Even if a mutation affects binding at one site in this region, antibodies targeting the remaining sites would still be protective.
Vaccine-induced antibodies cover many more sites in this region than those from natural infection, and therefore are less likely to be affected by a mutation at any site.
The study only looked at antibodies stimulated by the Moderna vaccine, but the results are likely to be the same for the Pfizer-BioNTech vaccine, he added.
“This could potentially be a good thing as the virus is creating mutations,” said Dr. Bloom.