Boosters Increase Protection Against Hospitalization and Death from COVID-19
February 7, 2022
Dayna Fischer, MS
Why do we need to get a booster shot for COVID-19? In a recent study published on February 4, 2022 by The Lancet, researchers studied COVID vaccine effectiveness in a group of 842,974 vaccinated people in Sweden. After receiving the first two doses of a mRNA vaccine, the study found that vaccine effectiveness declined in the four to six months after vaccination, specifically against the Delta variant. However, additional studies show that receiving a booster dose significantly increases protection against COVID and the Omicron variant.
The study previously mentioned took place in Sweden. The 842,974 vaccinated participants in the study were vaccinated with two doses of either the Pfizer-BioNTech, Moderna, or AstraZeneca vaccines between December 2020 to October 2021. The study found that the effectiveness of the Pfizer BioNTech vaccine fell from 92 percent to 47 percent 121–180 days from the time of vaccination. The effectiveness of the Moderna vaccine declined from 96 percent to 59 percent 181 days after vaccination. The effectiveness of the AstraZeneca vaccine waned from 89 percent to 66 percent after 121 days.
The majority of the effectiveness of the vaccines dropped between day 30 to day 100+ after vaccination. However, with a third dose (booster), vaccine effectiveness has shown to significantly increase. In a pre-print study published on January 14, 2022 by nature.com, research found that among participants in England, effectiveness of the Pfizer-BioNTech and Moderna booster dose improved protection from 85 to 90 percent against Delta, after two initial doses of the Pfizer-BionNTech or AstraZeneca vaccines.
Another study (pre-print) published by medrxiv.org, looked at vaccine effectiveness against Omicron in a group of participants in England. Vaccine effectiveness increased to 71.4 percent with an AstraZeneca booster dose. With the PfizerBioNTech booster dose, vaccine effectiveness increased to 75.5 percent two weeks after boosters were given. In a chart provided by Dr. Eric Topol on Twitter, data shows that a booster dose provided more than 70 percent protection against hospitalization and death for Omicron for people in all age groups in England.
Vaccine effectiveness is continuously being studied. What is known is that new variants are inevitable, according to the World Health Organization. However, vaccinations plus a booster provide significant protection against severe disease, hospitalization, and death from COVID-19. Even if a more serious variant emerges, people who are vaccinated and boosted will be well protected.
In good health. MT
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