Pandemic risk stemming from the bovine H5N1 outbreak: an account of the knowns and unknowns.

H5N1 subtype influenza A viruses represent a long-standing pandemic concern. Owing to their global occurrence in poultry, humans are routinely exposed to these viruses, and hundreds of human cases have been documented worldwide since 2003. The relevant viral lineages are not static, however, and have recently undergone a massive expansion of host range and geographic distribution.

Comparison of the incidence and risk factors of COVID-19 and influenza associated acute respiratory illnesses: Results of the SHIVERS-II, III, IV prospective community cohort study.

Background: While severe outcomes among hospitalised patients with COVID-19 and influenza are well described, comparative studies on community transmission and milder illnesses associated with COVID-19 and influenza are lacking.

Methods: We compared incidence, risk/protective factors, and clinical features among prospective community cohort participants with PCR-confirmed COVID-19-associated and influenza-associated acute respiratory illnesses (ARI) from 7-February to 2-October 2022 in Wellington, New Zealand.

Findings: The crude COVID-19-associated ARI incidence was 59/100 person-years (PY).

Rapid surge of reassortant A(H1N1) influenza viruses in Danish swine and their zoonotic potential.

In 2018, a single detection of a novel reassortant swine influenza A virus (swIAV) was made in Denmark. The hemagglutinin (HA) of the virus was from the H1N1 pandemic 2009 (H1N1pdm09) lineage and the neuraminidase (NA) from the H1N1 Eurasian avian-like swine lineage (H1N1av). By 2022, the novel reassortant virus (H1pdm09N1av) constituted 27% of swIAVs identified through the Danish passive swIAV surveillance program.

Emergence of a novel reassortant highly pathogenic avian influenza clade 2.3.4.4b A(H5N2) Virus, 2024.

Reassortant highly pathogenic avian influenza A(H5N2) clade 2.3.4.