Jong JC de ,
Bestebroer TM ,
Bijlsma K ,
Verweij C
31 p
in Dutch
1994
Toon Nederlands
English Abstract In the framework of the influenza virus surveillance of
RIVM we have examined 195 influenza virus strains isolated in various
European countries and Japan during the season 1992/93. Haemagglutination
inhibition (HI) assasys showed the H3N2-virus strains to come into two
groups of roughly equal sizes. One group was similar to the strains
circulating in 1991/92, including the vaccine strain of the season 1992/93,
whereas the other group belonged to a new variant, typified by strain
A/Beijing/32/92. The antigenic difference between the two groups was
unusually large for two contemporary variants of H3N2-virus. This
implicates that people, even when infected with influenza virus A (H3N2) in
1991/92 or vaccinated in November 1993, were poorly protected against the
new virus variant. Probably this explains the high number of excess deaths
(1800) that was observed in the Netherlands early in 1993. Interestingly,
antigenic as well as molecular analysis demonstrated a relationship between
the new virus variant and sporadically circulating deviant H3N2-viruses from
Chine, Singapore, and France isolated in 1990 and early 1991. During the
epidemic, in the Netherlands two other H3N2-virus strains were isolated
which apparently originated from pigs. The numerous influenza B virus
strains and the few Influenza A (H1N1) virus strains isolated in 1992/93
well matched the respective vaccine strains used in this
season.
