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Pfizer Says COVID Shot 85% Effective After 1 Dose; May Not Require Deep Freeze

FRIDAY, Feb. 19, 2021 (HealthDay News) -- There was a double dose of good news Friday from COVID vaccine maker Pfizer: The company said just one dose may provide 85% protection against SARS-CoV-2, and vials of the vaccine might not require ultra-cold storage after all.

The latter finding could be a game-changer for vaccine distribution, because the need for refrigerators capable of storing vaccines at temperatures down to -112 degrees Fahrenheit has been a major roadblock at centers across the United States. The U.S. government is set to distribute hundreds of millions of doses of the two-dose Pfizer vaccine to Americans over the coming months.

Now, based on results from ongoing vaccine "stability studies," Pfizer now believes that its vaccine could be safely stored for up to two weeks at standard freezer temperatures of just -13°F to 5°F.

As reported by CBS News, Pfizer CEO Albert Bourla said the company will now request that the U.S. Food and Drug Administration change its guidance on the storage of the vaccine, which was developed along with its German partner, BioNTech.

"We appreciate our ongoing collaboration with the FDA and CDC as we work to ensure our vaccine can be shipped and stored under increasingly flexible conditions," Bourla said. "If approved, this new storage option would offer pharmacies and vaccination centers greater flexibility in how they manage their vaccine supply."

Not only is storage and distribution of the Pfizer vaccine perhaps made easier, but there's also new data suggesting that strong protection against the new coronavirus sets in after just one dose.

According to research published in The Lancet medical journal, the first dose of the shot gave health care workers at Israel's largest hospital 85% protection.

The Sheba hospital near Tel Aviv began vaccinating its workers as far back as Dec.19, CBS News reported. Over 9,000 people are employed at the hospital; about 7,000 received the first dose of the Pfizer vaccine and the others weren't inoculated.

Tracking down hospital staff who'd either gone on to develop COVID-19 symptoms or had been in contact with people known to be infected, the Israeli researchers found 170 cases of COVID-19.

Comparing rates of infection between those who'd gotten the first dose of the the vaccine versus those who hadn't been inoculated, they calculate that protection reached 47% between day 1 and day 14 post-vaccination, and 85% between day 15 to day 28.

"What we see is a really high effectiveness already right after two weeks, between two weeks to four weeks after vaccine," study co-author Gili Regev-Yochay told a small group of journalists, CBS News reported.

The findings build on prior Israeli findings, which found the Pfizer vaccine to be 95% effective one week after a second dose.

Does all this mean that vaccinated people can't transmit SARS-CoV-2 to other people?

"That is the big, big, question. We are working on it. This is not on this paper and I hope we will have some good news soon," Regev-Yochay said.

More information

Find out more about COVID-19 vaccines at the U.S. Centers for Disease Control and Prevention.


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