04/25/2022 09:47 (act 04/25/2022 14:02)
The effectiveness of Pfizer’s booster against Omikron significantly diminishes after just three months. ©Photo by Robyn Beck / AFP
One study shows that Omicron protection wears off after just three months after a booster vaccination with the Biontech/Pfizer vaccine.
After a booster vaccination with the Biontech/Pfizer vaccine, Omikron’s initially high level of protection from inpatient treatment wanes after just a few months, according to new study data. That’s according to a Southern California study published in The Lancet Respiratory Medicine.
Omicron protection after booster is already after three months
“Covid-19 booster injections with Pfizer/Biontech significantly improve protection against omicrons, although after three months this protection appears to diminish against emergency department visits and even hospitalizations,” summarized the study’s lead author, epidemiologist Sara Y. Tartof of the Health Consortium Kaiser Permanente, according to the statement. Even so, however, a certain effectiveness remained.
For the study, researchers analyzed 11,123 hospital admissions and emergency room visits that did not result in hospitalization for an acute respiratory infection. In the investigation period from December 2021 to February 2022, both the delta variant and the omicron variant were in circulation.
Pfizer study: omicron protection decreased to 55%
Results of the Pfizer-funded study: After three doses, the effectiveness of the Biontech/Pfizer vaccine against omicron hospitalizations was 85% in the first three months. But it dropped to 55% after three months or so. In terms of alerting an emergency room, the effectiveness of three doses in less than three months versus Omicron was 77%, but dropped to 53% after three months or more.
Greater vaccine effectiveness at Delta
For the delta variant, trends in decreasing efficacy against SARS-CoV-2 were generally similar, however, efficacy was estimated to be greater than for the omicron variant at each time point. On average, the effect of the Biontech/Pfizer vaccine against Omicron was significantly greater after three doses than after two doses.
Fourth corona vaccination recommended for risk groups
In Austria, the National Vaccination Committee (NIG) recommends a fourth vaccination for risk groups only. This applies to people over 80 in general and to people over 65 with previous illnesses. They should be immunized again within the first four months, ideally six months after the third bite. However, everyone else should not be denied vaccination either. In early April, the EU medicines agency EMA stated that a fourth dose is currently not required for all citizens. However, it may make sense for people over 80, given the higher risk of serious illness from Covid.