Public healthUniversal vaccines would allow wide-scale flu prevention

Published 28 February 2012

An emerging class of long-lasting flu vaccines could do more than just save people the trouble of an annual flu shot; a flu pandemic is difficult to predict and typically impossible to control through vaccination alone; universal vaccines, however, act on virus targets that are relatively constant across all types of flu, even pandemic flu

Universal vaccines have a broad impact on influenza outbreaks // Source: .ne.gov

Princeton University-based researchers have found that the “universal” vaccine could for the first time allow for the effective, wide-scale prevention of flu by limiting the influenza virus’ ability to spread and mutate. Universal, or cross-protective, vaccines — so named for their effectiveness against several flu strains — are being developed in various labs worldwide and some are already in clinical trials.

A Princeton University release reports that the researchers recently reported in the Proceedings of the American Academy of Sciences that the new vaccines would make a bout with influenza less severe, making it more difficult for the virus to spread. At the same time, the vaccines would target relatively unchanging parts of the virus and hamper the virus’ notorious ability to evolve and evade immunity; current flu vaccines target the pathogen’s most adaptable components.

A computational model the team developed showed that these factors could achieve unprecedented control of the flu virus both seasonally and during outbreaks of highly contagious new strains.

Cross-protective vaccines could even improve the effectiveness of current vaccines, which are designed to only fight specific flu strains, the researchers report.

Controlling the flu, which is now like “chasing a moving target,” could advance from the current reaction stage to that of real population-wide prevention, said lead author Nimalan Arinaminpathy, a postdoctoral research associate in Princeton’s Department of Ecology and Evolutionary Biology.

Because the flu quickly evolves to escape host immunity, current vaccines tend to be prioritized for inoculating specific high-risk groups such as asthma sufferers and the elderly every year,” Arinaminpathy said.

So, at the moment, vaccine programs focus on clinical protection for those receiving the vaccine, but we hope to eventually graduate to being able to control the virus’ spread and even its evolution,” he said. “Our model provides a strong conceptual basis as to how and why the ‘universal’ vaccines would achieve that.”

The research presents a realistic and important assessment of how the universal vaccines’ ability to work against a breadth of flu strains can be wielded to benefit public health, said James Lloyd-Smith, an assistant professor of ecology and evolutionary biology at the University of California-Los Angeles. Lloyd-Smith had no role in the study, but is familiar with it.

This is the first study that looks at the population consequences of the next generation of vaccines, both in terms of epidemiological impact and evolutionary impact on the virus,” Lloyd-Smith said. “They combined the latest information out