| Abstract: | This article describes the epidemiology and
antigenic drift of influenza, A (H3N2) virus in
Shanghai from 1968 through 1981. There wa.s
clear evidence of change in epidemioilogical
characteristics a.round 1977. The epidemic due to
influenza A (HINl) virus in August 1977 affected
mainly youngsters and children, but the HINI
epidemic in 1981 affected mostly adults. The
process of antigenic variation. of H3N2 virus and
the relationship between HINl and H3N2 in-
fluenza epidemics are discus.sed on the basis of
an analys.is of influenza surveillance data in this
city during these years. |
