Does a lack of vaccine side effects correlate with reduced BNT162b2 mRNA vaccine response among healthcare workers and nursing home residents?

Aging Clin Exp Res. 2021 Nov;33(11):3151-3160. doi: 10.1007/s40520-021-01987-9. Epub 2021 Oct 15.


Background: The BNT162b2 SARS-CoV-2 mRNA vaccination has mitigated the burden of COVID-19 among residents of long-term care facilities considerably, despite being excluded from the vaccine trials. Data on reactogenicity (vaccine side effects) in this population are limited.

Aims: To assess reactogenicity among nursing home (NH) residents. To provide a plausible proxy for predicting vaccine response among this population.

Methods: We enrolled and sampled NH residents and community-dwelling healthcare workers who received the BNT162b2 mRNA vaccine, to assess local or systemic reactogenicity and antibody levels (immunogenicity).

Results: NH residents reported reactions at a much lower frequency and lesser severity than the community-dwelling healthcare workers. These reactions were mild and transient with all subjects experiencing more local than systemic reactions. Based on our reactogenicity and immunogenicity data, we developed a linear regression model predicting log-transformed anti-spike, anti-receptor-binding domain (RBD), and neutralizing titers, with a dichotomous variable indicating the presence or absence of reported reactions which revealed a statistically significant effect, with estimated shifts in log-transformed titers ranging from 0.32 to 0.37 (all p < 0.01) indicating greater immunogenicity in subjects with one or more reported reactions of varying severity.

Discussion: With a significantly lower incidence of post-vaccination reactions among NH residents as reported in this study, the BNT162b2 mRNA vaccine appears to be well-tolerated among this vulnerable population. If validated in larger populations, absence of reactogenicity could help guide clinicians in prioritizing vaccine boosters.

Conclusions: Reactogenicity is significantly mild among nursing home residents and overall, subjects who reported post-vaccination reactions developed higher antibody titers.

Keywords: COVID-19; Immunogenicity; Nursing homes; Reactogenicity; Vaccination.

MeSH terms

  • BNT162 Vaccine
  • COVID-19 Vaccines
  • COVID-19*
  • Health Personnel
  • Humans
  • Nursing Homes
  • RNA, Messenger / genetics
  • SARS-CoV-2
  • Vaccines*


  • COVID-19 Vaccines
  • RNA, Messenger
  • Vaccines
  • BNT162 Vaccine