mRNA and Protein Subunit COVID-19 Vaccine Reactogenicity and Their Relationship to Productivity for Healthcare Workers and First Responders

Objectives: To compare the percentage of participants that experienced any solicited reactogenicity symptom after 1 dose of the updated 2024-2025 adjuvanted protein-based Novavax (NVX; JN.1) or Pfizer-BioNTech mRNA (PFZ; KP.2) COVID-19 vaccine within 2 and 7 days post-vaccination and examine its impact on daily life. Methods: In this prospective, interventional, real-world study (SHIELD/NCT06633835), previously vaccinated healthcare workers (HCWs) and first responders (FRs) from Salt Lake City, Utah, United States, and surrounding areas self-selected to receive NVX or PFZ. At 2 and 7 days post-vaccination, participants self-reported on 11 vaccine-related reactogenicity symptoms and functional impairment using a 5-item modified Sheehan Disability Scale. Results: Five hundred eighty-eight participants completed the day 2 questionnaire (NVX, n =219; PFZ, n =369); 583 completed the day 7 questionnaire (NVX, n =217; PFZ, n =366). Two days post-vaccination, NVX recipients were less likely to report a systemic (OR =0.40; 95% CI, .21-.75) or local (OR =0.10; 95% CI, .03-.33) reactogenicity symptom and lost 50% fewer work hours (0.7 vs 1.4 hours) and 66% fewer productive hours (0.8 vs 2.4 hours) than PFZ recipients. There was little to no difference between vaccines at 7 days post-vaccination. Conclusions: Fewer reactogenicity symptoms following COVID-19 vaccination suggest use of the 2024-2025 adjuvanted protein-based NVX vaccine as an immunization option with a lower impact on daily life. These findings may inform policymakers, clinicians, and hospital systems regarding vaccine tolerability, which may influence HCW and FR behavior regarding COVID-19 vaccines.