Live Attenuated Influenza Vaccines for Pandemic Preparedness

Naturally occurring PAE206K point mutation in 2009 H1N1 pandemic influenza viruses impairs viral replication at high temperatures

The emergence of influenza virus A pandemic H1N1 in April 2009 marked the first pandemic of the 21st century. In this study, we observed significant differences in the polymerase activities of two clinical 2009 H1N1 influenza A virus isolates from Chinese and Japanese patients. Sequence comparison of the three main protein subunits (PB2, PB1, and PA) of the viral RNA-dependent RNA polymerase complex and subsequent mutational analysis revealed that a single amino acid substitution (E206K) was responsible for the observed impaired replication phenotype. Further in vitro experiments showed that presence of PAE206K decreased the replication of influenza A/WSN/33 virus in mammalian cells and a reduction in the virus's pathogenicity in vivo. Mechanistic studies revealed that PAE206K is a temperature-sensitive mutant associated with the inability to transport PB1-PA complex to the nucleus at high temperature (39.5 ​°C). Hence, this naturally occurring variant in the PA protein represents an ideal candidate mutation for the development of live attenuated influenza vaccines.

Australian high-level public policy preparedness for population-based triage during the pandemic

The COVID-19 pandemic brought attention to scarce clinical resource allocation via secondary population-based triage (S-PBT) throughout the international healthcare community. Experiences overseas highlighted the importance of coordinated and consistent approaches to allocating resources when facing overwhelming demand, particularly for critical care. Noting the importance of consistency and the system of devolved governance deployed in Australia, this study aimed to identify and analyse sources of high-level policy that affect Australia’s health system preparedness for the operationalisation of S-PBT. Of the 39 documents reviewed, 17 contained potential references to S-PBT. There was a lack of clear recommendations and guidance to inform S-PBT operationalisation and, where provided, advice conflicted between documents. Many jurisdictions did not detail how S-PBT would be operationalised and failed to delineate stakeholder responsibilities. These results are important as they reveal a lack of high-level jurisdictional policy preparedness for coordinated and consistent S-PBT operationalisation. These results offer insights and opportunities for enhanced disaster preparedness as clinicians, policymakers and academics critically reflect on pandemic responses. The results show a need for enhanced preparedness around the management of overwhelming demand and clinical resource management in Australia.