Correlation of adverse effects and antibody responses following homologous and heterologous COVID19 prime-boost vaccinations.

BACKGROUND

Studies correlating reactogenicity and immunogenicity of COVID-19 vaccines are limited to BNT162b2, with inconsistent results. We investigated whether adverse reactions after other COVID-19 vaccines reliably predict humoral responses.

METHODS

Adult volunteers were recruited for homologous or heterologous prime-boost vaccinations with adenoviral (ChAdOx1, AstraZeneca) and/or mRNA (mRNA-1273, Moderna) vaccines administered either 4 or 8 weeks apart. Adverse effects were routinely solicited and recorded by subjects in a standard diary card for up to 84 days post booster vaccination. Anti-SARS-CoV-2 IgG titers were measured pre- (visit 1), and post-booster dose at days 14 (visit 2) and 28 (visit 3).

RESULTS

A total of 399 participants (75% women) with a median age of 41 (interquartile range, 33-48 IQR) years were included. Vaccine-induced antibody titers at days 14 and 28 were significantly higher among subjects who reported local erythema, swelling, pain, as well as systemic fever, chills, headache, myalgia, arthralgia, fatigue compared to those who did not experience local or systemic reactogenicity. Post-vaccination humoral responses did not correlate with the occurrence of skin rash and correlated weakly with gastrointestinal symptoms. A significant correlation between post-vaccination peak body temperature and anti-SARS-CoV-2 spike IgG at Day 14, independent of vaccine type and schedule, was found.

CONCLUSION

Specific symptoms of reactogenicity such as post-vaccination injection site pain, swelling, erythema and fever, myalgia and fatigue are significantly predictive of the magnitude of the anti-SARS-CoV-2 antibody response.