Until this study, little was known regarding the durability of protection following this 3rd dose of mRNA vaccine, especially during these later periods of Delta or Omicron dominance. However, some recent epidemiological studies have shown the increasing incidence of ” breakthrough infections or breakthrough infections -occurring following vaccination, other studies have pointed to the strong immune escape capability of the Omicron variant (therefore in particular with regard to vaccine immunity).
Efficacy nevertheless confirmed once morest severe forms
“mRNA vaccines, including the booster, are very effective, but their effectiveness decreases over time. Our results suggest that additional doses may be needed to maintain protection once morest COVID-19, particularly for higher risk population groups.”said study co-author Brian Dixon of the Regenstrief Institute, director of public health informatics at the Indiana University School of Public Health.
- More vulnerable minority communities (in the United States): researchers have thus observed that Hispanic or Afro-American communities are half as likely to have this 3rd dose, which therefore makes them more vulnerable to the complications of the disease.
Effective in particular once morest hospitalization: Overall, the analysis finds that people who received the 2nd and 3rd doses of an mRNA vaccine developed better protection once morest hospitalizations but not once morest visits to the emergency room/urgent care (or severe but potentially severe symptoms). not require hospitalization).
The efficacy of the vaccine turns out to be lower overall during the Omicron period than during the Delta period.
Variable vaccine efficacy depending on the variants:
- the efficacy of the vaccine once morest visits to the emergency room or the management of the sheaves thus goes from 97% during the first 2 months following the 3rd dose to 89% efficacy 4 months or more during the period of delta predominance ( summer/early fall 2021);
- the effectiveness of the vaccine once morest visits to the emergency room or management in the sheaves thus goes from 87% during the first 2 months following the 3rd dose to 66% effectiveness 4 months or more during the period of Omicron predominance (late fall 2021/winter 2021-22);
- vaccine efficacy once morest hospitalization thus increases from 96% in the first 2 months following the 3rd dose to 76% efficacy 4 months or more during the delta-predominant period (summer/early fall 2021 );
- the efficacy of the vaccine once morest hospitalization thus increases from 91% during the first 2 months following the 3rd dose to 78% efficacy 4 months or more during the Omicron-dominant period (late fall 2021/ winter 2021-22);
Thus, the study confirms the importance of receiving a 3rd dose of the COVID-19 mRNA vaccine to prevent moderate to severe forms of the disease, however the researchers clearly specify:
“especially in people with comorbidities.”
But the study also warns of the rapid decline in vaccine immunity, just a few months following the 3rd dose.
