Experts have been tracking H5N1 clade 2.3.4.4b since it emerged in 2020, but there have recently been reports of mass deaths in infected mammals from seals to bears, as well as a possible mammal-to-human outbreak on a Spanish mink farm last year. – Mammal transmission has picked up. Worry
However, very few human cases have been reported, and the WHO currently assesses the threat to humans as low.
“This is a natural experiment before us, and I don’t think we are complacent,” said Nicola Lewis, director of the WHO Collaborating Center on Influenza at the Crick Institute in London. Speaking before the meeting, he said it would include an assessment of the situation around the world.
The experts also discussed possible vaccine development.
WHO-affiliated laboratories already have two strains of flu virus that are closely related to the circulating H5N1 virus, which could be used by vaccine manufacturers to make a human vaccine if needed. One of them was added after the last WHO flu meeting in September 2022, and laboratories around the world are currently testing how closely the two subtypes match the strain that spreads between animals to determine whether Whether any further update is required or not.
Many of the companies that make seasonal flu vaccines may also make pandemic flu vaccines. For example, GSK and CSL Seqirus are already working with the United States Biomedical Advanced Research and Development Authority (BARDA) to test shots based on one of the closely related strains.
WHO’s Briand said having these strains ready could save about two months in vaccine development. But developing a vaccine quickly enough in the face of a pandemic will still remain a challenge, experts said.