No abstract

Among adult subjects experimental infection with a single serotype of adenovirus was accompanied by an increase in titers of antibodies not only to the serotype causing infection but also, in lesser degree, to heterologous serotypes.The severity of clinical reactions depended to a statistically significant degree on the levels of heterologous antibodies present in the blood prior to infection.Previously vaccinated subjects whose antibody titers decreased during a period of 900 days to intermediate or low levels were found to be susceptible to repeated experimental infections in variable degrees.It seems probable that human resistance to repeated overt infection with adenoviruses is maintained at a high level for many years of ]ire by regular contact with adenoviruses of different serotypes. Depending on the immunologic status of the host, pathogenicity of the virus and other factors such infections may have varying degrees of clinical severity, sometimes causing mild or asymptomatic forms. Repeated infection with adenovirus of one and the same serotype is only possible after prolonged absence of contact with both homologous and heterologous serotypes.