Seasonal
coronaviruses have been circulating widely in the
human population for many years. With increasing age,
humans are more likely to have been exposed to these
viruses and to have developed
immunity against them. It has been hypothesized that this
immunity to seasonal
coronaviruses may provide partial
protection against
infection with
severe acute respiratory syndrome coronavirus 2 (
SARS-CoV-2 ) and it has also been shown that coronavirus disease 2019 (COVID-19)
vaccination induces a
back -boosting effects against the spike
proteins of seasonal
betacoronaviruses . In this study, we tested if
immunity to the seasonal
coronavirus spikes from OC43, HKU1, 229E or NL63 would confer
protection against
SARS-CoV-2 challenge in a
mouse model, and whether pre-existing
immunity against these spikes would weaken the
protection afforded by
mRNA COVID-19
vaccination . We found that
mice vaccinated with the seasonal
coronavirus spike
proteins had no increased
protection as compared to the negative controls. While a negligible
back -boosting effect against
betacoronavirus spike
proteins was observed after SARS-CoV-2 infection, there was no negative original antigenic sin-like effect on the
immune response and
protection induced by
SARS-CoV-2 mRNA vaccination in
animals with pre-existing
immunity to seasonal
coronavirus spike
proteins . ImportanceThe impact that
immunity against seasonal
coronaviruses has on both susceptibility to SARS-CoV-2 infection as well as on COVID-19
vaccination is unclear. This study provides insights into both questions in a
mouse model of
SARS-CoV-2 .