Single Dose Vaccination in Healthcare Workers Previously Infected with SARS-CoV-2

Saadat, S.; Rikhtegaran-Tehrani, Z.; Logue, J.; Newman, M.; Frieman, M. B.; Harris, A. D.; Sajadi, M. M.

Coronavirus disease 2019 (COVID-19) vaccine shortages have led some experts and countries to consider untested dosing regimens. We studied antibody responses to a single dose of the Pfizer-BioNTech or Moderna vaccines in healthcare workers (HCW) with laboratory-confirmed COVID-19 infection and compared to them to antibody responses of HCW who were IgG negative to SARS-CoV-2 spike protein. HCW with prior COVID-19 showed clear secondary antibody responses to vaccination with IgG spike binding titers rapidly increasing by 7 days and peaking by days 10 and 14 post-vaccination. At all time points tested, HCW with prior COVID-19 infection showed statistically significant higher antibody titers of binding and functional antibody compared to HCW without prior COVID-19 infection (p<.0001for each of the time points tested). In times of vaccine shortage, and until correlates of protection are identified, our findings preliminarily suggest the following strategy as more evidence-based: a) a single dose of vaccine for patients already having had laboratory-confirmed COVID-19; and b) patients who have had laboratory-confirmed COVID-19 can be placed lower on the vaccination priority list.