Study of Taiwan seniors finds flu vaccine can cut TB risk
A large longitudinal study of an elderly population in Taiwan found that flu vaccination reduced the risk of tuberculosis (TB) infection by 18%. Earlier studies, including animal ones, have hinted that flu vaccination might protect against a range of pathogens, including TB, due to activation of T-cell mediated immunity. A team from Taiwan reported the findings yesterday in Emerging Infectious Diseases.
The group's data come from Taiwan's comprehensive universal health insurance program. The setting provides a unique opportunity to study the disease, because TB has been Taiwan's most prevalent notifiable infectious disease for decades, and health officials keep track of cases through a national surveillance system. The cohort study from 2005 to 2012 included 99,982 seniors, 64,290 who were vaccinated and 35,692 who were not. Flu vaccination is voluntary in Taiwan.
During the study period, 1,141 TB cases were reported, for an incidence of 1.14%. Among vaccinated older people, the team found 142.2 cases per 100,000 person-years, compared with 175.5 cases per 100,000 person-years in the unvaccinated group.
After adjusting for demographic factors, concurrent medical conditions, and income level, the group concluded that elderly people in Taiwan who were vaccinated against flu had a lower risk of TB than their unvaccinated peers. They added that given an earlier report that suggested even a partially effective vaccine against TB would reduce the burden of the disease, their new findings suggest that flu vaccination should be offered to seniors to prevent TB infections.
Jan 23 Emerg Infect Dis study
Nanoparticle universal flu vaccine shows promise in mouse study
A nanoparticle universal flu vaccine designed to protect against a range of influenza A viruses was protective and produced long-lasting immunity in mice, a research team based at Georgia State University (GSU) reported today in Nature Communications.
Many experts have called for flu vaccines that are more effective, with gaps in protection in the current flu season, especially against H3N2, and unpredictable pandemic threats, such as from H7N9 in China, underscoring the urgency. In 2012, a team led by the University of Minnesota's Center for Infectious Disease Research and Policy (CIDRAP), the publisher of CIDRAP News, pressed for better flu vaccines, emphasizing that new efforts should target viral components other than the head of the hemagglutinin (HA) protein on the virus's surface, which is always changing, requiring constant reformulation and revaccination.
In the new study, researchers designed a vaccine that targets surface glycoproteins on the stalk of the virus, a more conserved part that all influenza viruses share. They assembled the stalk domain into a protein nanoparticle as part of a vaccine.
In a press release from GSU, Bao-Zhong Wang, PhD, study coauthor and associate professor in the Institute for Biomedical Sciences, said once the vaccine is given, the nanoparticle protects the antigen protein so it won't be degraded. "Our immune cells have a good ability to take in this nanoparticle, so this nanoparticle is much, much better than a soluble protein to induce immune response."
To test the effectiveness, the team immunized mice twice intramuscularly, then challenged them with several influenza viruses, including H1N1, H3N2, H5N1, and H7N9. The vaccine provided universal and complete protection against lethal virus exposure and dramatically cut the amount of virus in the lungs.
The group's next goal is to test the nanoparticle vaccine in ferrets, an animal model used for studying human influenza because of the animals' generally similar clinical signs and respiratory physiology.
Jan 24 Nat Commun abstract
Jan 24 GSU press release