After 6 months, the efficacy of the Pfizer COVID-19 vaccine drops to 84 percent, but a booster is effective for Delta.
According to Pfizer CEO Albert Bourla, the COVID-19 vaccine produced by Pfizer-BioNTech loses potency four to six months after the second injection.
Bourla highlighted a new company-funded study that demonstrated Pfizer’s vaccine had 96.2 percent effectiveness within two months of the second dose during an interview on CNBC’s “The Exchange.” Every two months, the efficacy rate reduces by 6%, and four to six months after the second dose, the efficacy rate is only around 84 percent.
The paper has yet to be peer-reviewed after being published on the preprint server medRxiv. It involves more than 44,000 people in the United States and other nations, and it comes as Pfizer and US health officials argue over whether a booster shot is needed to strengthen COVID-19 protection.
According to CNBC, Bourla added, “The good news is that we are very, very sure that a third treatment, a booster, would push up the immune response to levels that will be enough to defend against the delta variety.”
In the United States, the highly contagious form now accounts for more than 80% of COVID-19 infections.
The company’s data will be formally submitted to US regulators by mid-August, according to the CEO, in order to make a case for the benefits of a third dose.
Pfizer revealed earlier this month that it intends to apply to the US Food and Drug Administration for approval of a third vaccination dose, citing recent findings from Israel that indicated diminishing protection six months after the second dose.
According to Reuters, Pfizer’s chief scientific officer Mikael Dolsten said at the time, “It’s a small data set, but I think the trend is accurate: Six months out, given that Delta is the most contagious version we’ve seen, it can cause infections and moderate illness.”
The FDA and the CDC then released a joint statement denying the necessity for a third dose.
“At this moment, Americans who have been completely vaccinated do not require a booster dose. The FDA, CDC, and NIH are working together on a science-based, rigorous approach to determine whether or not a booster is necessary, according to the joint statement.
Dr. Kate O’Brien, the World Health Organization’s director of immunization, contradicted the FDA and CDC’s positions on booster vaccines on Wednesday, saying that a third dosage is not recommended at this time.