Pfizer Vaccine's Immunity Falls After 90 Days Of Administration, Booster Dose Can Prevent This: Study

Pfizer Vaccine: Studies reveal that immunity developed against COVID-19 due to administration of Pfizer's vaccine reduces over time.

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Pfizer Vaccine: According to a study, immunity against COVID-19 developed after taking Pfizer's vaccine reduces over time. This study also showed that the risk of infection increases 90 days after taking the second dose of Pfizer's vaccine. A study by Leumit Health Services, an Israeli Research Institute, found that vaccine immunity decreases over time. Emphasis has also been laid on the need for a booster dose of the vaccine. Israel's vaccination drive began in December 2020, but since June 2021, positive COVID-19 case numbers have begun increasing since June 2021.

Massive COVID-19 vaccination campaigns are being carried out by countries worldwide in an attempt to control the spread of COVID-19, but scientists believe that even in countries with high vaccination rates, infection rates can increase as vaccine's immunity reduces over time. 

The researchers reviewed 'Electronic Health Records' for 80,057 adults with an average age of 44, who underwent a PCR test at least three weeks after taking their second dose and had no evidence of them infected with COVID-19. Of these 80,057 participants, 7,973 participants (9.6%) were found to be infected. Their report was then compared with the report of people from the same age and ethnic group that was examined the same week who were not found infected.

After looking at other potentially effective factors, the researchers found an increased risk of infection among people who have had more time passed after being administered with the second dose. Compared to the initial 90 days after being given the second dose, the risk of infection in all age groups was 2.37 times higher after the passage of 90-119 days, 2.66 times higher after the passage of 120-149 days, 2.82 times more after the passage of 150-179 days and 2.82 times higher after the passage of 180 days or more.