Considering the zoonotic and pandemic risk of HPAI

FOLLOWING its emergence in 1996 in domestic waterfowl in southern China, the highly pathogenic avian influenza (HPAI) A (H5N1) virus has been responsible, via its clade 2.3.4.4b, for several catastrophic disease outbreaks among wild and domestic birds and mammals.1 Importantly, a significant proportion of the virus-affected species are geographically and phylogenetically distant from each other. Compared to its parental A (H5N8) clade 2.3.4.4b, the novel reassortant HPAI A (H5N1) virus appears to be characterised by an increased ability to cross species barriers, thus infecting multiple mammalian species, including human beings. This is the main reason why it is being increasingly perceived as a global zoonotic and pandemic threat.1, 2 Marine mammals have also shown a high susceptibility to HPAI A (H5N1) clade 2.3.4.4b virus, with South American sea lions (Otaria flavescens), southern elephant seals (Mirounga leonina) and marine otters (Lontra felina) having been heavily struck by the disease along the Pacific and Atlantic coasts of South America.3 “No evidence of a sustained interhuman viral transmission has yet been reported We must surely focus our efforts on a ‘One Health, One Earth, One Ocean‘-centred approach for tackling this ever-evolving zoonotic and pandemic risk.