mRNA-1273 shows greater COVID-19 protection than NVX-CoV2705 in retrospective US cohort study
This retrospective matched cohort study analyzed data from a large US claims database, comparing COVID-19 outcomes in 69,140 mRNA-1273 recipients and 34,570 NVX-CoV2705 recipients who were matched on demographic and clinical factors. The population consisted of US insured adults aged 18 years or older, with follow-up from day 7 after vaccination through up to 180 days.
For the primary outcome of medically-attended COVID-19, mRNA-1273 showed an adjusted comparative vaccine effectiveness (cVE) of 31.7% (95% CI 23.4% to 39.1%) compared to NVX-CoV2705, with 706 events (1.02%) in mRNA-1273 recipients versus 512 events (1.48%) in NVX-CoV2705 recipients. For hospitalization with COVID-19, the adjusted cVE was 40.7% (95% CI 13.5% to 59.4%), with 61 events (0.09%) in mRNA-1273 recipients and 49 events (0.14%) in NVX-CoV2705 recipients. In recipients aged 65 years or older, adjusted cVE was 25.7% for medically-attended COVID-19 and 41.7% for hospitalization.
Safety and tolerability data were not reported in this analysis. Key limitations include the observational design, which cannot establish causality, potential residual confounding despite matching, reliance on claims data for outcome ascertainment, and lack of information on prior infection status or variant exposure. The study was conducted in a US insured population, which may limit generalizability.
For clinical practice, these findings suggest a potential effectiveness difference between these vaccine platforms in real-world use, but the retrospective nature and absence of safety data warrant cautious interpretation. The results may inform vaccine selection discussions while awaiting prospective comparative data.