A third and fourth dose of COVID-19 vaccine provided substantial protection among adults with healthy immune systems who were eligible to receive them during the evolution of the Omicron variant in early 2022, according to a new MMWR. published today. The results of this study, along with recently published data showing that people infected with BA.2 may also have antibodies that can protect against disease with BA.5, suggest that currently available vaccines may provide protection against serious disease. caused by BA. .5 variant.
To evaluate the efficacy of 2, 3, and 4 doses of COVID-19 mRNA vaccines (Pfizer-BioNTech or Moderna) among adults with healthy immune systems, the experts examined data from the VISION network at more than 214,000 home visits. ’emergency / emergency care and more than 58,000. hospitalizations with a diagnosis of COVID-19-like disease in 10 U.S. states from mid-December 2021 to mid-June 2022. The results of the study show:
- When BA.1 was the predominant variant, vaccine (VE) effectiveness was 61% for two doses against COVID-19-associated hospitalizations; EV increased between 85% and 92% after receiving a third dose / booster.
- When BA.2 / BA.2.12.1 became predominant, the efficacy of the two-dose vaccine was 24% against hospitalizations associated with COVID-19 and increased to 52% -69% thereafter. of a third / booster dose.
- Patterns were similar for emergencies and urgent care meetings, with a lower EV during BA.2 / BA.2.12.1 predominance and a higher EV with 3 or 4 doses compared to EV with 2 doses.
- Among adults 50 years of age or older during BA.2 / BA.2.12.1, the effectiveness of the COVID-19-associated hospitalization vaccine was 55% more than 4 months after a booster dose. / third and increased to 80% more than a week later. the fourth dose
COVID-19 vaccines remain our most important tool for protecting people from serious illness, hospitalization, and death. Getting vaccinated now will not stop you from getting a specific variant vaccine authorized in the fall or winter when you are recommended. Given the recent increases in deaths and hospitalizations associated with variant BA.5, everyone should be up to date on recommended COVID-19 vaccines, including additional booster doses for those with moderate immunodeficiency. severe and adults over 50 years of age.