JOHNSON & JOHNSON announced on Friday that its one-dose coronavirus vaccine provided strong protection against Covid-19, potentially offering the United States a third powerful tool in a desperate race against a worldwide rise in virus mutations.
But the results came with a significant cautionary note: The vaccine’s efficacy rate dropped from 72 per cent in the United States to 57 per cent in South Africa, where a highly contagious variant is driving most cases.
Studies suggest that this variant also blunts the effectiveness of Covid vaccines made by Pfizer-BioNTech, Moderna and Novavax. The variant has spread to at least 31 countries, including the United States, where two cases were documented this week.
Johnson & Johnson said that it planned to apply for emergency authorization of the vaccine from the Food and Drug Administration as soon as next week, putting it on track to receive clearance later in February.
“This is the pandemic vaccine that can make a difference with a single dose,” said Dr. Paul Stoffels, the chief scientific officer of Johnson & Johnson.
The company’s announcement comes as the Biden administration is pushing to immunize Americans faster even with a tight vaccine supply.
White House officials have been counting on Johnson & Johnson’s vaccine to ease the shortfall. But the company may only have about seven million doses ready when the F.D.A. decides whether to authorize it, according to federal health officials familiar with its production, and about 30 million doses by early April.
The variant from South Africa, known as B.1.351, could make things even worse for the vaccine push. Given the speed at which the variant swept through that country, it is conceivable that by April it could make up a large fraction of infections in the United States. That would undermine the effectiveness of available vaccines.
The fact that four vaccines backed by the federal government seem to be less effective against the B.1.351 variant has unsettled federal officials and vaccine experts alike. Facing this uncertainty, many researchers said it was imperative to get as many people vaccinated as possible — quickly. Lowering the rate of infection could thwart the contagious variants while they are still rare, and prevent other viruses from gaining new mutations that could cause more trouble.
“If ever there was reason to vaccinate as many people as expeditiously as we possibly can with the vaccine that we have right now, now is the time,” Dr. Anthony S. Fauci, the government’s top infectious disease expert, said in an interview. “Because the less people that get infected, the less chance you’re going to give this particular mutant a chance to become dominant.”
As the United States scrambles to get enough vaccines, the country is turning into something of an evolutionary experiment. The B.1.351 variant is one of several that have arrived in the country or originated here, all with the ability to spread faster than other variants.
“The pandemic is a lot more complicated now than it was a couple months ago,” said Dr. Dan Barouch, a virologist at Beth Israel Medical Center in Boston.
Vaughan Cooper, an evolutionary biologist at the University of Pittsburgh, said that all the new variants were likely evolving quietly for months before bursting on the scene. “I think we’re going to see many stories like this,” he said.
Federal regulators are also still waiting on data from Johnson & Johnson’s new manufacturing facility in Baltimore that prove it can mass-produce the vaccine. The company is counting on that factory to help reach its contractual pledge to the federal government of 100 million doses by the end of June.
If Johnson & Johnson can deliver vaccines quickly enough to the United States, it might be able to help drive down cases before variants make things worse. Since the vaccine requires only a single shot — unlike the Moderna and Pfizer-BioNTech vaccines, which require two — that delivery would translate into full coverage for 100 million people.
Johnson & Johnson’s vaccine has another advantage that might help speed up the rollout. It can stay viable in a refrigerator for three months, while the two authorized vaccines have to be kept frozen. That gives the company an edge not just in reaching more isolated parts of the United States, but in getting the vaccine to remote areas of the world that could otherwise seed more aggressive mutants.
“If you talk about the potential impact on the developing world, I believe it’s much more relevant than here,” Dr. Fauci said.
But vaccine makers also have to prepare for the B.1.351 variant or another one surging to dominance and demanding new vaccines. “You’ve got to be nimble enough to be able to adapt by upgrading our vaccines that match the dominant strain,” Dr. Fauci said.
Exactly when to make that switch will be a difficult decision, because the viruses are spreading unpredictably, and manufacturing new doses will be a huge undertaking, the New York Times reports.
“The implications of that are big. You would not take that choice lightly,” said John D. Grabenstein, an epidemiologist with the Immunization Action Coalition, a nonprofit organization that disseminates information about vaccines. “It’s not doomsday. It’s just that we are going to need a bigger boat.”
Johnson & Johnson’s announcement came one day after Novavax said an early analysis of its 15,000-person trial in Britain had revealed that the two-dose vaccine had an efficacy rate of nearly 90 percent there. But in a small trial in South Africa, the efficacy rate dropped to just under 50 percent.
Johnson & Johnson presented only a summary of findings of its clinical trial. The vaccine was 85 percent effective in preventing severe disease in all three regions where the trial was run: the United States, Latin America and South Africa. After 28 days, none of the vaccinated participants who developed Covid-19 had to be hospitalized.
The company reported that the vaccine’s protective effect seems to increase with time. But without long-term data on immunity, scientists and regulators do not yet know whether the vaccine’s efficacy peaks at some point before dropping.
– The New York Times
