During the early spread of omicron variants in the first quarter of 2022, national data compiled by the CDC show the Janssen/Johnson & Johnson Ad26.COV2.S vaccine plus mRNA doses were as effective as 3 doses of mRNA vaccines and better than 2 doses of Ad26.COV2.S. “Vaccination continues to be an important preventive measure for reducing the public health impact of COVID-19,” the authors conclude.
Deidentified datasets from medical and pharmacy insurance claims and COVID-19 vaccination data from community pharmacies were linked using privacy-preserving record linkage. Among 18.9 million adults, relative vaccine effectiveness (rVE) was determined for 3 recipient cohorts: (1) primary Ad26.COV2.S vaccine and Ad26.COV2.S booster (two Ad26.COV2.S), (2) primary Ad26.COV2.S vaccine and mRNA booster (Ad26.COV2.S+mRNA), (3) two doses of primary mRNA vaccine and mRNA booster (three mRNA). The results showed: “Compared with two Ad26.COV2.S doses, Ad26.COV2.S + mRNA and three mRNA doses were more effective against all COVID-19 outcomes, including 57% (95% CI: 52–62) and 62% (95% CI: 58–65) rVE against an [emergency department] visit; 44% (95% CI: 34–52) and 54% (95% CI: 48–59) rVE against hospitalization; and 48% (95% CI: 22–66) and 66% (95% CI: 53–75) rVE against ICU admission, respectively.”