Study shows single dose of Pfizer vaccine 85% effective, Fauci says two doses still needed

Just a single dose of Pfizer’s mRNA coronavirus vaccine was shown to be 85% effective in a new study out of Israel, but Dr. Anthony Fauci said it’s crucial we stick to the two-dose regimen.

“Even though you can get a fair degree of quote ‘protection’ after a single dose, it clearly is not durable, we know that,” said Fauci, the nation’s top infectious disease doctor in a Friday press briefing.

The Israeli study of more than 7,000 vaccinated health care workers published Thursday in The Lancet shows a single shot of the Pfizer vaccine is 85% effective in preventing symptomatic disease 15 to 28 days after being given.

The shot was 47% effective in the first two weeks after administration, according to the research.

The authors wrote, “Early reductions of COVID-19 rates provide support of delaying the second dose in countries facing vaccine shortages and scarce resources.”

They added, “Longer follow-up to assess long-term effectiveness of a single dose is needed to inform a second dose delay policy.”

In addition to the issue of durability with just one shot, Fauci said the second vaccine dose induces 10 times the neutralizing antibodies when compared to the first dose, which is key in staying within the range of protection against variants.

“When you’re dealing with variants, you want enough of a height of a response that even if you diminish it, you don’t diminish it so much to get out of the realm of protection,” Fauci said.

If a patient has a less optimal response to a vaccine due to a single dose, immunological pressure on the virus could also, in theory, induce more variants, said Fauci.

Andy Slavitt, senior adviser to the White House COVID-19 Response Team, said there won’t be any changes in vaccine administration guidance, “We’re not going to be persuaded by one study that happens to grab headlines.”

In other news from Pfizer, the company submitted data to the Food and Drug Administration that could allow vaccine doses to be stored at temperatures more commonly found in pharmaceutical freezers and refrigerators.

As of now, the vaccines need to be kept in ultra-cold freezers at temperatures of -112 degrees to ‑76 degrees which many rural areas and developing nations don’t have. Updated guidance would allow storage of -13 degrees to 5 degrees.

“We have been continuously performing stability studies to support the production of the vaccine at commercial scale, with the goal of making the vaccine as accessible as possible for health-care providers and people across the U.S. and around the world,” said Albert Bourla, chairman and CEO of Pfizer.

As more stability data become available, Pfizer anticipates the shelf life and expiration date could be extended, too, the company said.

from Boston Herald https://ift.tt/3aCFwJc