The effectiveness of the Biontech/Pfizer COVID-19 vaccine decreases significantly just a few months after a booster shot, according to a study by Kaiser Permanente. The study found that protection against severe COVID-19 and hospitalization decreases after a booster shot, particularly with the Omikron variant. However, the vaccine still provides some level of protection for a longer period. Epidemiologist Sara Y. Tartof explains that “COVID-19 booster shots with Pfizer/Biontech significantly improve protection against Omikron, although this protection seems to decrease after three months against emergency room visits and even hospitalizations.” The study, published in The Lancet Respiratory Medicine, analyzed data from 11,123 severe COVID-19 cases treated in hospitals between December 2021 and February 2022, during which both the Delta and Omikron variants were present.
The study, which was funded by Pfizer, found that after three doses of the Biontech/Pfizer vaccine, the vaccine prevented hospitalization from Omikron infection by 85% in the first three months, but this protection decreased to 55% after three months. The vaccine also prevented emergency room visits by 77% in the first three months, but this protection decreased to 53% after three months. The study also found that the vaccine’s effectiveness against the Delta variant decreased similarly. However, the vaccine’s effectiveness against the Delta variant was consistently higher than against the Omikron variant. The study also showed that the vaccine’s protection against the Omikron variant was significantly higher after three doses than after two doses.
In Germany, the Standing Committee on Vaccination (STIKO) of the Robert Koch Institute recommends a second booster shot for seniors over 70 years old and people with underlying health conditions due to the rapidly decreasing effectiveness of the vaccine. Health Minister Karl Lauterbach recently called for a second booster shot for people over 60 years old. In contrast, the European Medicines Agency (EMA) suggested in early April that a fourth vaccine dose may be beneficial for people over 80 years old. The study’s findings highlight the need for continued monitoring of vaccine effectiveness and the potential need for additional booster shots to maintain protection against COVID-19.
