This is how acquired immunity from Pfizer vaccine weakens over time.

A new study on the effectiveness of the COVID-19 vaccine from Pfizer / Biontech found that protection against the virus generated by the vaccine drops to about 84% four to six months after receiving the second dose.

The survey, funded by the company itself, found that the vaccine’s effectiveness was 96.2% higher one to two months after receiving the second dose.

The study also showed that the efficacy decreased by an average of 6% every two months, and the vaccine was tested on more than 44,000 volunteers, and it appeared that after four months, the efficacy decreased to 83.7% in most fully vaccinated individuals. .

The funding for the study comes at a time when Pfizer is pushing for approval to give a third dose of its vaccine to boost protection against the virus, something U.S. health officials have opposed. As it stands, the Centers for Disease Control and Prevention (CDC) as well as the Food and Drug Administration (FDA) do not recommend booster doses for fully vaccinated people.

“Fully vaccinated Americans do not need a booster dose at this time,” the Department of Health and Human Services (HHS) said in a press release. She explained that the Food and Drug Administration, the Centers for Disease Control and Prevention and the National Institutes of Health are involved in a rigorous scientific process to determine if and when a booster dose is necessary, according to the American chain FOX.

According to the data, if the vaccine’s efficacy continues to decline at a rate of 6%, the protection against the virus will be 50% around 18 months after the full vaccination.

The study also showed that despite the reduction, the vaccine was 97% effective against severe symptoms for at least six months.