Photo Credit: Muhammad Shoaib
The following is a summary of “Expert consensus on the benefits of neuraminidase in conventional influenza vaccines: a Delphi study,” published in the January 2025 issue of Infectious Disease by Youhanna et al.
Seasonal vaccination had been the main method for preventing human influenza, with licensed vaccines regularly updated for viral mutations and standardized for haemagglutinin content, though their effectiveness remained suboptimal.
Researchers conducted a retrospective study to evaluate the clinical benefits of neuraminidase (NA) in influenza vaccines, as NA evolves more gradually than hemagglutinin but is not a mandated or standardized component.
They gathered expert opinions on the importance of NA in influenza vaccines using a 2-stage Delphi survey, 9 statements on NA were formulated by a steering committee after a targeted literature review. In the 1st round, panellists from 3 continents were asked to indicate their agreement with each statement and assess the strength of evidence and provided explanations for their answers and suggested revisions. Consensus was defined as ≥75% agreement, with statements lacking consensus revised and included in the 2nd round.
The results showed 9 panellists with diverse NA-related expertise, including clinical, research, and public health, completed the survey. The consensus was reached that anti-NA responses from natural infection or vaccination were linked to protective immunity independent of haemagglutinin and that NA offered additional benefits, such as improving disease severity. The experts also identified knowledge gaps regarding heterologous cross-reactivity of vaccine-induced anti-NA antibodies, the correlation between anti-NA titres and reduced transmission or infection risks, and differences in anti-NA responses to seasonal influenza vaccines.
Investigators concluded the NA as a crucial component of influenza vaccines with associated benefits, standardizing NA content and further research into optimizing vaccines for anti-NA effects could potentially enhance their overall efficacy.
Source: bmcinfectdis.biomedcentral.com/articles/10.1186/s12879-024-10277-4
