Johnson & Johnson, the only major drugmaker developing a single-dose vaccine for covid-19, announced Friday that its shot provided strong protection, potentially offering another powerful tool in a desperate race against a worldwide rise in virus mutations.
But the results hold a significant cautionary note: The vaccine's efficacy rate dropped from 72% in the United States to 57% in South Africa, where a highly contagious variant is driving most cases.
Studies suggest that this variant also blunts the effectiveness of the 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.
With these results, Johnson & Johnson became the fifth company supported by the U.S. government to develop an effective vaccine in less than a year, and the only one that doesn't need two doses -- a big advantage when most countries are struggling to get shots in arms more quickly.
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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 U.S.-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 also in getting the vaccine to remote areas of the world that could otherwise seed more aggressive mutants.
"Frankly, simple is beautiful," said Dr. Matt Hepburn, the U.S. government's covid-19 vaccine response leader.
"Now it's going to be incumbent on us ... to figure out how this great tool in the toolbox can be used ... so that we ultimately cover the American population and ultimately stop this pandemic," Hepburn said.
The Johnson & Johnson vaccine was extremely effective in preventing severe cases of covid -- including serious illness caused by the variant, the company said. Though less effective than the Moderna and Pfizer vaccines now authorized in the United States, the new one is still considered a strong vaccine by scientists. Annual flu vaccines, for example, are typically 40% to 60% effective.
'GOOD ENOUGH'
Data is mixed on how well other vaccines being used around the world work, but the Pfizer and Moderna shots were 95% protective in large U.S. studies compared with Johnson & Johnson's 72%.
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It's not fair, however, to compare studies done before the record surges of recent months and the discovery of mutants; they might not turn out the same today, cautioned Dr. Jesse Goodman of Georgetown University, a former FDA vaccine chief.
The Johnson & Johnson protection is "good enough to help attack a pandemic," Goodman said. "The advantage of having more vaccine, in a single shot, would be significant."
"Gambling on one dose was certainly worthwhile," said Dr. Mathai Mammen, global research chief for Johnson & Johnson's Janssen Pharmaceutical unit.
"This is a really great result," agreed Akiko Iwasaki, immunologist at Yale University. "I hope this vaccine gets approved as soon as possible to reduce disease burden around the world."
The one-shot vaccine could be a "game changer," said Jonathan Temte, a vaccine expert at the University of Wisconsin School of Medicine and Public Health -- streamlining the vaccination effort and freeing mass vaccination clinics from the need to recall people for boosters and the logistical complications.
"Back in July and August, I was hoping we would see a vaccine that was 60% effective -- in my mind, that would be great. And now we have had two that have hit the ball out of the park and set expectations spectacularly high, and that's not fair, because we don't need a home run all the times we're up to bat," Temte said.
A solution to the pandemic, he said, isn't a perfectly effective vaccine, but a vaccination campaign that can reach large portions of the population as quickly as possible -- comparing it to a baseball team that wins with steady base hits and bunts, not just home runs.
Jose Romero, health secretary of Arkansas and chairman of an advisory committee to the Centers for Disease Control and Prevention, said vaccines of different efficacy might end up targeted to different populations. He laid out a hypothetical scenario in which one vaccine was 90% effective and another was 60 to 70%.
"I'd want to use the vaccine with higher efficacy in my most vulnerable population," Romero said. "I'd think about 60[%] to 70% efficacy in a younger population where we know that the secondary morbidity and mortality is much lower."
COLD VIRUS CARRIER
The new vaccine uses a different technology from the two U.S.-authorized vaccines, broadening the suite of tools to block the virus. The Johnson & Johnson vaccine employs a harmless cold virus to deliver a gene that carries the blueprint for the spiky protein found on the surface of the coronavirus. The virus infects cells, which then follow the genetic instructions to construct a replica of the coronavirus spike.
In contrast, the Pfizer and Moderna vaccines use a strip of genetic material called messenger RNA to instruct cells to build the spiky protein found on the surface of the coronavirus.
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In both cases, the immune system learns to recognize the real virus by mustering an immune response to the spike.
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. The shot could be authorized and available to the public by March.
"This is the pandemic vaccine that can make a difference with a single dose," said Dr. Paul Stoffels, chief scientific officer of Johnson & Johnson.
The company's announcement was made 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 have only about 7 million doses ready at the outset, according to federal health officials familiar with its production, and about 30 million doses by early April.
The variant from South Africa 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.
The fact that at least four vaccines backed by the federal government seem to be less effective against the South Africa 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," said Dr. Anthony Fauci, the government's top infectious-disease expert. "Because the less people that get infected, the less chance you're going to give this particular mutant a chance to become dominant."
'MORE COMPLICATED'
As the United States scrambles to get enough vaccines, the country is turning into something of an evolutionary experiment. The South Africa variant is one of several that have arrived in the country or originated here, all with the ability to spread faster.
"The pandemic is a lot more complicated now than it was a couple months ago," said Dr. Dan Barouch, a virus expert at Beth Israel Medical Center in Boston.
Vaughan Cooper, an evolutionary biologist at the University of Pittsburgh, said all the new variants were probably 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 still waiting on data from Johnson & Johnson's new manufacturing facility in Baltimore. 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 -- for $1.5 billion.
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, that delivery would translate into full coverage for 100 million people.
The company expects to supply 1 billion doses globally by year's end.
Still, Johnson & Johnson and other vaccine-makers must prepare for the South Africa 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," 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.
EU OKS ASTRAZENECA
Also Friday, regulators authorized AstraZeneca's coronavirus vaccine for use in adults throughout the European Union, after criticism that the bloc is not moving quickly enough to vaccinate its population.
The European Medicines Agency's expert committee unanimously recommended the vaccine for people 18 and older, although concerns had been raised that there is not enough data to prove it works in older people, and some countries indicated they may not give it to the elderly.
The shot is the third vaccine given the green light by the European Medicines Agency and the European Commission after shots by Pfizer and Moderna.
"I expect the company to deliver the 400 million doses as agreed. We will keep on doing all we can to secure vaccines for Europeans, our neighbours & partners worldwide," tweeted EU Commission President Ursula von der Leyen.
With trials showing about 60% efficacy, the vaccine appears to offer less protection than the ones already authorized, but experts have said any vaccine with an efficacy rate of over 50% could help stop outbreaks.
The agency recommended the vaccine's use by older people, despite limited data regarding its efficacy in people older than 55, citing the immune responses seen and experience with other vaccines.
"At least some protection is expected," Bruno Sepodes of the agency's expert committee said at a briefing. He acknowledged that "the exact level of protection cannot be estimated for the time being."
Many countries on the continent have been struggling to vaccinate people as quickly as Britain, Israel, the U.S. and others, and it was long hoped that the AstraZeneca shot would help speed things up at a time when countries face surging cases in a pandemic that has taken the lives of more than 400,000 people in the bloc.
The EU bet heavily on the shot, which is cheaper and easier to handle than some other vaccines, with orders for 300 million doses to be delivered after authorization and options for another 100 million doses.
"None of them is a magic wand on its own, but together they provide tools and options to prevent different aspects of the disease," said Emer Cooke, head of the medicines agency.
Information for this article was contributed by Carl Zimmer, Noah Weiland and Sharon LaFraniere of The New York Times; by Lauran Neergaard, Linda A. Johnson, Frank Jordans, Maria Cheng, Samuel Petrequin, Raf Caser, Nicole Winfield, Danica Kirka, Angela Charlton, Alex Turnbull and Jan M. Olsen of The Associated Press; and by Carolyn Y. Johnson of The Washington Post.
