Source: The Mail Online
The risk of covid-19 infection more than doubles 90 days after the second dose of the Pfizer vaccine according to an Israeli study.
The study involved 80,000 adults who had been vaccinated with the Pfizer-BioNTech vaccine.
Researchers from the Leumit Health Services in Israel and the U.S. National Institutes of Health (NIH) found that the virus risk more than doubled and continued to increase as far as six months out.
They now say that booster shots are needed in order to sustain long-term protection from covid.
The Mail Online reports: What’s more,the percentage of tests coming back positive for COVID-19 quadrupled from 2.4 percent at least 90 days later to 10.6 percent at least 150 days later.
The finding add more evidence that, while the Pfizer vaccines provides strong protection in the initial weeks, booster shots are likely needed to sustain long-term protection from Covid.
Israel was one of the first countries to roll out use of Pfizer’s Covid vaccine in December 2020 and the U.S. was not far behind.
The Middle Eastern country experienced a resurgence in cases in September while infections are creeping up now in the U.S.
This has led many experts to fear that immunity from the standard two-dose regimen wanes over time.
Researchers say determining the risk of infection as more time elapses since dose two can lead to important information about the optimal timing of a third dose.
For the study, published in The BMJ, the team looked at the electronic health records of 80,057 adults in Israel.
All of the adults were fully vaccinated with the Pfizer shot and had no history of a prior COVID-19 infection.