People Who Received Older Pfizer COVID Vaccines Had Similar Outcomes as Unvaccinated: Study

Pfizer-funded study finds no benefit for all vaccines except for the newest version.

A man receives a dose of Comirnaty Omicron XBB 1.5 Pfizer vaccine in a file image. Pascal Pochard-Casabianca/AFP via Getty Images

People who received any version of Pfizer’s COVID-19 vaccine except for the newest one were no better off than the unvaccinated, according to a new paper.

“Compared to the unvaccinated, those who had received only older versions of COVID-19 vaccines did not show significantly reduced risk of COVID-19 outcomes, including hospital admission,” Sara Tartof of Kaiser Permanente and her co-authors wrote.