Reactogenicity Differences between Adjuvanted, Protein-Based and Messenger Ribonucleic Acid (mRNA)-Based COVID-19...

Area of Science:

• Immunology
• Vaccinology
• Public Health

Background:

• COVID-19 vaccine reactogenicity can cause hesitancy towards updated vaccinations.
• Real-world data on reactogenicity after primary series completion is crucial for informed vaccine choices.

Purpose of the Study:

• To compare the reactogenicity of a protein-based vaccine (NVX-CoV2373) versus mRNA vaccines (BNT162b2 or mRNA-1273) in a real-world setting.
• To assess solicited local and systemic adverse events within 48 hours post-booster vaccination.

Main Methods:

• Observational, post hoc analysis of the 2019nCoV-406 study.
• Included 1130 participants receiving a booster dose of NVX-CoV2373 (n=303) or mRNA vaccine (n=827).
• Propensity score adjustments were used to control for confounding factors.

Main Results:

• Lower adjusted rates of systemic reactogenicity events (60.5% vs. 84.3%) and local events (73.4% vs. 91.7%) were observed with NVX-CoV2373 compared to mRNA vaccines.
• Fewer mean systemic symptoms (1.8 vs. 3.2) and local symptoms (1.5 vs. 2.4) were reported for NVX-CoV2373 recipients.
• A significantly lower incidence of ≥3 systemic reactogenicity symptoms was seen with NVX-CoV2373 (33.9% vs. 61.4%).

Conclusions:

• The adjuvanted protein-based NVX-CoV2373 vaccine demonstrated significantly lower systemic and local reactogenicity compared to mRNA vaccines.
• These findings support NVX-CoV2373 as a viable immunization option with a potentially more favorable side effect profile.
• Reduced reactogenicity may help alleviate vaccine hesitancy and improve uptake of updated COVID-19 vaccines.