Pfizer covid vaccine booster shot - Booster Shots and Additional Doses for COVID

But the effectiveness against Omicron-related hospitalization started to wane at about the three-month mark.

William Schaffner, a professor of preventative medicine at Vanderbilt University, told UK health site.

He also noted that the vaccine efficacy of 53 percent at three months or longer is similar to the protection a flu shot might provide.

As per the CDC bulletin, the third or booster dose will be available for people who are considered mildly or severely immunocompromised.