Vaccine effectiveness

As we navigate yet another flu season, the perennial race to outsmart the influenza virus has led to remarkable scientific insights that are now aiding in the prediction and the improvement of vaccine effectiveness. A timely study conducted by researchers Melia E. Bonomo, Rachel Y. Kim, and Michael W. Deem from Rice University’s Department of Physics and Astronomy, in conjunction with the Center for Theoretical Biological Physics and the Department of Bioengineering, has shed light on the shifting landscapes of influenza quasispecies and the ramifications for vaccine efficacy in the 2018/19 season.

Published in the prestigious journal Vaccine (Vol. 37, Issue 24, Pages 3154–3158), the article titled “Modular epitope binding predicts influenza quasispecies dominance and vaccine effectiveness: Application to 2018/19 season,” explores how modular binding sites on the influenza A(H3N2) hemagglutinin protein are evolving. DOI: 10.1016/j.vaccine.2019.03.068, the study meticulously illustrates the connection between epitope changes and the challenge of staying ahead of the virus’ mutations.

By examining the hemagglutinin (HA) epitopes, the sites where antibodies attach to neutralize the virus, researchers have discerned that there was an emergent antigenic cluster which grew from 4% to 11% of the circulating strains from the 2017/18 to the early 2018/19 flu seasons. This finding signals significant implications for global health given that the HA protein is the primary target for flu vaccinations.

The study utilized elaborate mathematical models to regress a module-based antigenic distance, a novel approach designed by the researchers to quantify changes in the HA protein, and thereby predict which viral strains would dominate the flu season and influence the effectiveness of the administered vaccines. The modular approach of the analysis considers the HA protein as an amalgamation of distinct structural regions, each with the potential to mutate independently and thus alter the antigenic properties of the virus, affecting vaccine-induced immunity.

Through this innovative methodology, the research team could anticipate the dominance of new influenza strains, providing clear evidence of the need for continuous revision of the flu vaccine composition—a task that is performed annually by global health experts, including those at the United States Centers for Disease Control and Prevention (CDC).

This groundbreaking study, supported by the U.S. government but not a direct product of it (Research Support, U.S. Gov’t, Non-P.H.S.), has profound implications for the annual vaccination planning processes. It not only increases the understanding of influenza virus evolution but also makes strides toward optimizing vaccine design thus ensuring higher vaccine potency and greater protection against the flu.

Keywords

1. Influenza Vaccine Effectiveness
2. Antigenic Distance and Immunity
3. Seasonal Influenza Forecasting
4. Vaccine Development and HA Epitopes
5. Influenza A(H3N2) Evolution

The potential of this study does not stop here – it poses critical questions and provides a framework that could be employed for predictive modeling of other rapidly mutating viruses. Upon reflection, Dr. Michael W. Deem highlighted the value of interdisciplinary research, saying, “Our approach effectively bridges physics, biology, and medicine to address a public health challenge that affects millions globally every year.” The study has incited a hopeful discourse among scientists and public health officials alike on the prospects of enhancing vaccine effectiveness in the face of the unpredictable nature of influenza viruses.

References

1. Bonomo, M. E., Kim, R. Y., & Deem, M. W. (2019). Modular epitope binding predicts influenza quasispecies dominance and vaccine effectiveness: Application to 2018/19 season. Vaccine, 37(24), 3154-3158. https://doi.org/10.1016/j.vaccine.2019.03.068

2. Centers for Disease Control and Prevention. (2018). Vaccine Effectiveness: How Well Do the Flu Vaccines Work? Retrieved from https://www.cdc.gov/flu/vaccines-work/vaccineeffect.htm

3. Plotkin, S., Orenstein, W., & Offit, P. (2017). Vaccines (7th ed.). Elsevier.

4. Smith, D. J., Lapedes, A. S., de Jong, J. C., Bestebroer, T. M., Rimmelzwaan, G. F., Osterhaus, A. D. M. E., & Fouchier, R. A. M. (2004). Mapping the Antigenic and Genetic Evolution of Influenza Virus. Science, 305(5682), 371-376. https://doi.org/10.1126/science.1097211

5. Wiley, D. C., & Skehel, J. J. (1987). The structure and function of the hemagglutinin membrane glycoprotein of influenza virus. Annual Review of Biochemistry, 56, 365-394. https://doi.org/10.1146/annurev.bi.56.070187.002053

For those tasked with public health and vaccine development, identifying and preempting the circulating strains is essential to protect public health, and this study provides a crucial tool in that arsenal. As we anticipate the offerings of modern medicine and science in response to the shifting tides of influenza strains, studies such as this offer a beacon of hope in safeguarding our future against the ever-present threat of seasonal flu.