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Study Finds Gradual Increase In COVID Infection Risk After Second Pfizer Vaccine

MIAMI (CBSMiami) -- Protection from the Pfizer COVID-19 vaccine wanes over time, according to a new study published in the British Medical Journal.

Researchers analyzed data from more than 80,000 adults in Israel who had no previous evidence of infection and who had received a PCR test at least three weeks after their second shot of the two-dose Pfizer vaccine.

The research found that while the Pfizer vaccine does offer strong protection in the initial weeks after vaccination, there is also a gradual increase in the risk of COVID-19 infection starting 90 days after receiving a second dose, meaning breakthrough infections are more likely three months after the shot.

This gradual loss of vaccine-induced immunity leads study authors to believe a booster shot may be necessary to prevent infection and spread of the virus.

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