The company funded the study, and the EMA continues to see no need for a fourth vaccination for everyone.
The initially high level of protection against hospitalizations and emergency room visits in Omicron decreases after only a few months following booster vaccination with the Biontech/Pfizer vaccine. New study data from Southern California published in The Lancet Respiratory Medicine shows this.
“Covid-19 booster vaccinations with Pfizer/Biontech significantly improve protection against omicron, although this protection appears to wane after three months against emergency department visits and even hospitalizations,” summarized the study’s lead author epidemiologist Sara Y. Tartof of the Kaiser Permanente Health Consortium. However, some effectiveness remained even then.
Researchers analyzed 11,123 hospitalizations and emergency department visits that did not result in hospitalization for an acute respiratory infection. Both the Delta and Omikron variants were in circulation during the study period, December 2021 to February 2022.
Protection is down to 55 percent after three months
The Pfizer-funded study found that after three doses, the effectiveness of Biontech-Pfizer’s vaccine against hospitalizations for Omikron was 85 percent in less than three months. But it dropped to 55 percent at three months or longer.
Regarding emergency department admissions, the efficacy of three doses at less than three months against Omicron was 77 percent but dropped to 53 percent at three months or longer.
EMA: Fourth dose not needed for all at this time
For the delta variant, trends were generally similar in the decline in efficacy against Sars-CoV-2, but efficacy was estimated to be higher than for the omicron variant at each time point. The effectiveness of the Biontech/Pfizer vaccine against Omicron was significantly higher on average after three doses than after two doses.
The EU Medicines Agency (EMA) had stated that the fourth dose for all citizens was not currently necessary. However, it could be helpful for people aged 80 and older, given the higher risk of severe covid disease.
- source: kurier.at/picture: pixabay.com
This post has already been read 511 times!