Study shows Pfizer booster shot has similar side effects to second dose

A preliminary study conducted in Israel found that the Pfizer-BioNTech booster shot causes similar side effects to the second dose, such as soreness at the injection site.

Israel began administering booster shots to fully vaccinated individuals over the age of 60 last month as part of its effort to stop the spread of COVID-19, especially as the highly infectious delta variant continues to take hold in the country as the dominant strain.

Israel’s largest health care provider, Clalit, announced on Sunday that more than 240,000 people have received a third dose of the Pfizer-BioNTech vaccine, according to Reuters.

Of those recipients, roughly 4,500 people participated in a survey about the booster shot, which they all received between July 30 and Aug. 1, Reuters reported.

Eighty-eight percent of participants said they felt “similar or better” compared to how they felt after receiving their second dose.

Thirty-one percent reported having side effects, the most common symptom being soreness at the spot where the shot was administered.

Roughly 0.4 percent of respondents said they had trouble breathing, and 1 percent said they received medical treatment because of one or more side effects.

Ran Balicer, Clalit’s chief innovation officer, said that although the survey results are “initial and self-reported,” they create a juxtaposition between the side effects from the second dose and booster shot which show that “in most cases they are similar or less in the booster.”

He said the survey results further bolster the benefits to getting inoculated.

“Although we do not yet have long-term research on the efficacy and safety of the third booster dose, for the personal risk management of any person aged 60 plus, these findings continue to point to the benefit of immunization now, along with careful behavior among adults and avoiding gathering in closed spaces,” Balicer said, according to Reuters.

The world is watching as Israel starts administering booster shots, with other countries weighing the decision of whether a third dose will be necessary to protect individuals against the delta variant or future strains that could potentially be more virulent or spread more easily.

Anthony Fauci, President Biden’s chief medical adviser, said Sunday that it is likely that some people will need booster shots to give them continued protection against the virus, especially as preliminary data show protection in fully vaccinated individuals decreasing over time.

Data released last month showed that the effectiveness of the Pfizer vaccine fell from 96 percent to 84 percent over six months.

Fauci said booster shots would likely be given to the elderly and immunocompromised first, as the initial vaccine rollout was, noting that it would happen “as soon as the data gets to us.”