July 12, 2021: -On Thursday, Pfizer and BioNTech announced they are developing a Covid-19 booster shot to target the delta variant as concerns increase about the highly transmissible strain that is already the dominant form of the disease in the United States.
Although they believe the third shot of their current two-dose vaccine can preserve the “highest levels” of protection against all present known variants, which include delta, they are “remaining vigilant” and developing an updated version of the vaccine.
“As seen in real-world evidence released from the Israel Ministry of Health, vaccine efficacy has declined six months after the vaccination, at the same time that the Delta variant becomes the dominate variant in the country,” the companies wrote.
“These findings are consistent with an ongoing analysis from the companies’ Phase 3 study,” they said.
“That is why we have said, and we continue to believe that it is likely, based on the totality of the data we have to date, that a third dose may be needed within 6 to 12 months after full vaccination,” they added.
Clinical studies could start by August, subject to regulatory approvals, said the companies.
The World Health Organization estimates delta to
be nearly 55% more transmissible than alpha, the variant first found in the U.K. that once dominated the U.S. While current evidence proves that Pfizer’s is highly effective against delta to prevent severe disease and death, it may not protect against mild disease and spreading the infection to others, said scientists.
On Monday, Israeli officials reported a decrease in the effectiveness of the Pfizer-BioNTech vaccine to prevent infections and symptomatic illness. Still, they said it was very effective in preventing severe disease.
In the U.S, health officials are urging all eligible Americans to get vaccinated as quickly as possible, especially before the fall season when delta is expected to cause another surge in new coronavirus cases in places with the lowest vaccination rates particularly.
About 1,000 counties in the U.S. have Covid vaccination coverage of less than 30%, primarily located in the Southeast and Midwest, CDC Director Dr. Rochelle Walensky recently said.
Pfizer and BioNTech are creating booster shots and are expected to shortly seek U.S. authorization for a third dose of its vaccine.
