What is the clinical evidence from this study?

Study design: Cohort. Population: COVID-19 vaccination reactogenicity (n=588). Intervention: Novavax (NVX; JN.1) COVID-19 vaccine vs. Pfizer-BioNTech mRNA (PFZ; KP.2) COVID-19 vaccine. Primary outcome: Systemic reactogenicity symptom at 2 days post-vaccination (OR 0.40, 95% CI 0.21-0.75).

What question did this study set out to answer?

The aim is to compare reactogenicity symptoms after vaccination with NVX and PFZ COVID-19 vaccines and their impact on productivity.

April 13, 2026Open Access

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

Key Result

The Novavax COVID-19 vaccine was associated with lower odds of systemic (OR 0.40; 95% CI 0.21-0.75) and local reactogenicity symptoms at 2 days post-vaccination compared to the Pfizer-BioNTech vaccine.

Key Points

The aim is to compare reactogenicity symptoms after vaccination with NVX and PFZ COVID-19 vaccines and their impact on productivity.
Prospective interventional study involving healthcare workers and first responders.
Participants self-selected to receive either NVX (protein-based) or PFZ (mRNA) vaccines.
Self-reported reactogenicity symptoms and functional impairment were collected at 2 and 7 days post-vaccination.
NVX recipients reported fewer systemic (OR=0.40) and local (OR=0.10) reactogenicity symptoms than PFZ recipients.
NVX recipients lost fewer work hours (0.7 vs 1.4 hours) and productive hours (0.8 vs 2.4 hours) compared to PFZ.
At 7 days post-vaccination, no significant differences in reactogenicity were observed between the two vaccines.

Study Design

Type

Cohort (n=588)

Structured PICO

Does the Novavax COVID-19 vaccine reduce reactogenicity symptoms and functional impairment compared to the Pfizer-BioNTech mRNA vaccine in healthcare workers and first responders?

Population

588 previously vaccinated healthcare workers (HCWs) and first responders (FRs) from Salt Lake City, Utah, United States, and surrounding areas

Intervention

1 dose of the updated 2024-2025 adjuvanted protein-based Novavax (NVX; JN.1) COVID-19 vaccine

Comparator

1 dose of the updated 2024-2025 Pfizer-BioNTech mRNA (PFZ; KP.2) COVID-19 vaccine

Outcome

백신 접종 후 2일 및 7일 이내에 요청된 반응성 증상을 경험한 참가자의 비율patient reported

The adjuvanted protein-based Novavax COVID-19 vaccine demonstrated lower early reactogenicity and less impact on productivity compared to the Pfizer-BioNTech mRNA vaccine.

Main Result

Effect estimate: OR 0.40 (95% CI 0.21-0.75)

Abstract

Abstract 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.