Daijiworld Media Network - New Delhi

New Delhi, Oct 6: Researchers have proposed integrating pandemic preparedness into routine seasonal influenza vaccination by developing vaccines capable of generating broader immune responses. The proposed “Before Day One” approach could provide partial protection against emerging pandemic influenza viruses while maintaining protection against seasonal disease.

Current pandemic preparedness strategies largely depend on developing strain-matched vaccines after a novel influenza virus emerges. Manufacturing and deploying such vaccines takes time, creating a period during which population immunity may be limited.

The proposed strategy would use established annual influenza vaccination programmes to build a degree of pandemic protection before an outbreak begins. Modelling cited by the researchers suggests that vaccine timing can be as important as efficacy, with earlier deployment of a moderately effective vaccine potentially providing greater public health benefits than delayed use of a more effective vaccine.

Even a 10% reduction in infections during the first pandemic wave could help reduce transmission and preserve healthcare capacity. Lowering early infections could also slow the spread of a pandemic, providing additional time to develop, manufacture and distribute a strain-matched vaccine.

Development efforts could focus on conserved regions of influenza viruses that change less extensively between strains. Candidate targets include hemagglutinin, neuraminidase and internal proteins capable of stimulating T-cell responses.

Rather than prioritising a particular vaccine platform or antigen, the proposed approach focuses on clinical outcomes. Broadly protective influenza vaccines would need to maintain effective seasonal protection while demonstrating the potential to reduce severe outcomes from novel pandemic viruses.

However, pre-pandemic efficacy trials against an unknown future strain are not possible. Developers would therefore need to establish relevant immune markers and use animal models and other evidence to assess the likely level of protection against emerging viruses.

For clinicians, such vaccines could eventually offer benefits beyond pandemic preparedness. Broader immune responses may reduce vulnerability to seasonal strain mismatch, limit year-to-year variation in influenza vaccine effectiveness and potentially reduce severe illness.

A seasonal vaccine capable of providing both routine influenza protection and baseline pandemic coverage could strengthen preparedness without requiring a separate vaccination programme. Continued development of broadly protective influenza vaccines could therefore offer benefits during ordinary influenza seasons while providing an additional layer of defence when a pandemic strain emerges.