Antibody reactivity to SARS-CoV-2 is common in unexposed adults and infants under 6 months.
Abdelilah MajdoubiChristina MichalskiSarah E O'ConnellSarah DadaSandeep NarpalaJean GelinasDisha MehtaClaire CheungManjula BasappaAaron C LiuMatthias GörgesVilte E BarakauskasJennifer MehalkoDominic EspositoInna SekirovAgatha N JassemDavid M GoldfarbDaniel C DouekAdrian B McDermottPascal M LavoiePublished in: medRxiv : the preprint server for health sciences (2020)
A majority of unexposed adults have pre-existing antibody reactivity against SARS-CoV-2. The lack of similar antibody reactivity in infants where maternal antibodies have waned suggests that this cross-reactivity is acquired, likely from repeated exposures to circulating coronaviruses.