The World Health Organisation said on Tuesday that measures were being taken to destroy potentially deadly samples of the 1957 influenza virus, sent out unintentionally for tests to more 3 700 laboratories in 18 countries.
The influenza virus to be destroyed, known as H2N2, vanished in 1968. ”Therefore, persons born after 1968 are expected to have no or only limited immunity to H2N2,” which is not contained in current trivalent influenza vaccines, the WHO said in a statement.
The US government called on the College of American Pathologists (CAP) to ask all laboratories in 18 countries that received samples containing the 1957 influenza virus to destroy them, the WHO said.
The organization was also calling for biosafety procedures to be reviewed ”for use on infuenza viruses that have not circulated recently in humans and against which the majority of the population would have no protective immunity”.
The WHO statement did not clarify whether the samples, which were to be used for ”proficiency testing,” were sent out by mistake.
”Normally, currently circulating influenza A viruses … are used for proficiency testing,” the WHO said. ”The H2N2 virus was distributed by CAP for the first time in October 2004.”
Samples of the 1957 virus — also known as H2N2 ‒ were sent out to 3 747 laboratories by CAP since October 2004, the WHO said in a statement. ‒ Sapa-AFP