A Yale study shows Pfizer and Moderna vaccines offer strong protection against Delta
Researchers took blood samples from healthcare workers in the Yale-New Haven Health System and exposed them to 16 different strains of the virus that can be found in Connecticut. They found workers who’d gotten the Pfizer or Moderna vaccine had strong immune system responses to most of the variants.
Yale epidemiologist Nathan Grubaugh, one of the study’s authors, said the peer-reviewed study shows the vaccines even work well against the now-common Delta variant.
“The vaccine breakthroughs that we are seeing happening doesn’t necessarily have as much to do with its ability to escape our antibodies,” he said. “Has more to do with the fact that a lot of us are several months post-vaccination and your immunity can wane.”
Another finding: people who were infected with COVID-19 before they were vaccinated had even more protection against the variants.
“People who have had two doses, it’s almost like they’ve had three,” he said. “Now, of course, we’d much rather have people get the vaccine than get their immunity through infection because then you reduce the risk for severe outcomes.”
The study is different from randomized FDA clinical trials that determine efficacy, like ones that determined the Pfizer vaccine is 95% effective against hospitalization from the original strain of COVID-19.
Grubagh said it’s hard to predict from the study if the vaccines could work against future variants because people’s immune system responses are just too varied. Next, he said he would like to expand the study to children to see if the vaccines offer them just as much protection.