Data presented at the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) Global Congress in April 2026 indicates that Sanofi's protein-based Nuvaxovid COVID-19 vaccine demonstrated a better tolerability profile than its investigational mRNA-based vaccine candidate, mNEXSPIKE, in a head-to-head comparative study. The study, which compared the two vaccine platforms, found that Nuvaxovid was associated with fewer and less severe solicited adverse events.
The research, led by Sanofi, involved participants receiving either the Nuvaxovid vaccine or the mNEXSPIKE candidate. According to the presented results, the rate of local and systemic reactions was lower in the Nuvaxovid group. This suggests that for individuals concerned about reactogenicity, the protein-based vaccine may offer a favorable alternative.
Both vaccines in the study were designed to target the Omicron XBB.1.5 variant. The findings highlight ongoing industry efforts to refine COVID-19 vaccine options, balancing efficacy, safety, and tolerability. The data was shared as part of the scientific program at the ESCMID congress, a key forum for infectious disease research.
It is important to note that this study focused primarily on tolerability and reactogenicity. Broader assessments of immunogenicity and real-world effectiveness against circulating variants were not the primary endpoints of this specific comparative analysis. Public health recommendations continue to advise vaccination with available authorized options.
