Randomized clinical trials of COVID-19 vaccines: Do adenovirus-vector vaccines have beneficial non-specific effects?
Christine S. Benn,
Frederik Schaltz-Buchholzer,
Sebastian Nielsen,
Mihai G. Netea,
Peter Aaby
Affiliations
Christine S. Benn
Bandim Health Project, Indepth Network, Apartado 861, Bissau, Guinea-Bissau; OPEN, Odense Patient Data Explorative Network, Institute of Clinical Research Odense University Hospital/ University of Southern Denmark, Odense, Denmark; Danish Institute of Advanced Science, University of Southern Denmark, Odense, Denmark; Corresponding author
Frederik Schaltz-Buchholzer
Bandim Health Project, Indepth Network, Apartado 861, Bissau, Guinea-Bissau; OPEN, Odense Patient Data Explorative Network, Institute of Clinical Research Odense University Hospital/ University of Southern Denmark, Odense, Denmark
Sebastian Nielsen
Bandim Health Project, Indepth Network, Apartado 861, Bissau, Guinea-Bissau; OPEN, Odense Patient Data Explorative Network, Institute of Clinical Research Odense University Hospital/ University of Southern Denmark, Odense, Denmark
Mihai G. Netea
Department of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, the Netherlands; Department of Immunology and Metabolism, Life and Medical Science Institute, University of Bonn, Bonn, Germany
Peter Aaby
Bandim Health Project, Indepth Network, Apartado 861, Bissau, Guinea-Bissau; OPEN, Odense Patient Data Explorative Network, Institute of Clinical Research Odense University Hospital/ University of Southern Denmark, Odense, Denmark
Summary: We examined the possible non-specific effects of novel mRNA- and adenovirus-vector COVID-19 vaccines by reviewing the randomized control trials (RCTs) of mRNA and adenovirus-vector COVID-19 vaccines. We calculated mortality risk ratios (RRs) for mRNA COVID-19 vaccines vs. placebo recipients and compared them with the RR for adenovirus-vector COVID-19 vaccine recipients vs. controls. The RR for overall mortality of mRNA vaccines vs. placebo was 1.03 (95% confidence interval [CI]: 0.63–1.71). In the adenovirus-vector vaccine RCTs, the RR for overall mortality was 0.37 (0.19–0.70). The two vaccine types differed significantly with respect to impact on overall mortality (p = 0.015). The RCTs of COVID-19 vaccines were unblinded rapidly, and controls were vaccinated. The results may therefore not be representative of the long-term effects. However, the data argue for performing RCTs of mRNA and adenovirus-vector vaccines head-to-head comparing long-term effects on overall mortality.
