Coronavirus Infections in Military Recruits
https://www.atsjournals.org/do.../arrd.1974.109.6.621
A seroepidemiologic study of respiratory infections due to coronaviruses OC43 and 229E occurring in U.S. Marine recruits in the winters of 1970, 1971, and 1972 was performed. The per cent of respiratory infections due to these strains was low (0 to 5 per cent) in 2 of the 3 years, but a sharp outbreak of OC43 infection occurred in the winter of 1970 and 1971. Fifty-two per cent of 75 trainees studied seroconverted to Coronavirus OC43, and 37 of the 39 seroconversions occurred while the men were hospitalized for acute respiratory disease. Lower respiratory tract disease was apparent in some of these men although many others had concomitant infection with adenovirus and/or Mycoplasma pneumoniae. In OC43 infection, a serum hemagglutination inhibition antibody titer of âĨ 40 was associated with protection (P = 0.002) against reinfection. Nevertheless, 43 per cent of men who became infected with OC43 virus had initial serum antibody titers of âĨ 20 and < 80.