Three Studies, One Result: Vaccines Point the Way Out of the Pandemic
New scientific research underscores the effectiveness of vaccines and their versatility in the fight against the coronavirus.
By Apoorva Mandavilli, Carl Zimmer and Rebecca Robbins
Three scientific studies released on Monday offered fresh evidence that widely used vaccines will continue to protect people against the coronavirus for long periods, possibly for years, and can be adapted to fortify the immune system still further if needed.
Most people immunized with the mRNA vaccines may not need boosters, one study found, so long as the virus and its variants do not evolve much beyond their current forms — which is not guaranteed. Mix-and-match vaccination shows promise, a second study found, and booster shots of one widely used vaccine, if they are required, greatly enhance immunity, according to a third report.
Scientists had worried that the immunity conferred by vaccines might quickly wane or that they might somehow be outrun by a rapidly evolving virus. Together, the findings renew optimism that the tools needed to end the pandemic are already at hand, despite the rise of contagious new variants now setting off surges around the globe.
“It’s nice to see that the vaccines are recapitulating what we’ve also seen with natural infection,” said Marion Pepper, an immunologist at the University of Washington in Seattle.
Deepta Bhattacharya, an immunologist at the University of Arizona, said, “Remember all that stuff at the beginning where people were panicking over antibodies vanishing?” With all the good news now, he said, “it’s hard for me to see how and why we would need boosters of the same thing every six to nine months.”
The coronavirus may be evolving, but so are the body’s defenders. In a study published in the journal Nature, researchers discovered that the vaccines made by Pfizer-BioNTech and Moderna set off a persistent immune reaction in the body that may protect against the coronavirus for years, in part because important immune cells continue to develop for longer than thought.
Ali Ellebedy, an immunologist at Washington University in St. Louis, and his colleagues reported last month that immunity might last for years, possibly a lifetime, in people who were infected with the coronavirus and later vaccinated.
But it was unclear whether vaccination alone might have a similarly long-lasting effect.
In the new study, his team found that 15 weeks after the first vaccination, immune cells in the body were still organizing — becoming increasingly sophisticated and learning to recognize a growing set of viral genetic sequences.
The longer these cells have to practice, the more likely they are to thwart variants of the coronavirus that may emerge. The results suggest that the vast majority of vaccinated people will be protected over the long term — at least, against the existing coronavirus variants.
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