Jc. De Jong et al., Antigenic drift in swine influenza H3 haemagglutinins with implications for vaccination policy, VACCINE, 17(11-12), 1999, pp. 1321-1328
In order to explore the occurrence of antigenic drift in swine influenza A(
H3N2) virus, we examined virus strains from outbreaks of respiratory diseas
e among finishing pigs in the Netherlands in 1996 and 1997 and from earlier
outbreaks. In contrast to swine H3N2 strains from the 1980s, the recent is
olates did not show significant cross-reactivity with human influenza A(H3N
2) viruses from 1972-1975 in haemagglutination inhibition tests. These new
strains form a separate branch in the phylogenetic tree of the HAI parts of
HA. We conclude that recently there has been considerable antigenic drift
within the swine H3N2 viruses in the Netherlands and Belgium and recommend
replacement of the A/Port Chalmers/1/73 (H3N2) strain in the current vaccin
e by a more recent swine H3N2 isolate. (C) 1999 Elsevier Science Ltd. All r
ights reserved.