Impact of age, gender, ethnicity and prior disease status on immunogenicity following administration of a single dose of the BNT162b2 mRNA Covid-19 Vaccine: real-world evidence from Israeli healthcare workers, December-January 2020

The Pfizer Covid-19 vaccine showed high efficacy in clinical trials but observational data from populations not included in trials are needed. We described immunogenicity 21 days post-dose 1 among 514 Israeli healthcare workers by age, gender, ethnicity and prior COVID19 infection. Immunogenicity was similar by gender and ethnicity but decreased with age. Those with prior infection had antibody titres one magnitude order higher than naive individuals regardless of the presence of detectable IgG antibodies pre-vaccination.