New flu burden estimate offers more detailed demographic picture
A new estimate of disease burden due to flu, the most detailed demographic analysis of its kind so far, found that lower respiratory tract infections (LRTIs) due to flu are linked to about 145,000 deaths each year across all age groups. Researchers from the Global Disease Burden 2017 Influenza Collaboration published their findings yesterday in The Lancet Infectious Diseases.
For the study, they looked at flu incidence, hospitalizations, and deaths for every country and select subnational areas by age and year from 1990 to 2017 as part of ongoing global disease study. For the flu death estimate of 145,000, the 95% confidence interval (CI) was 99,000 to 200,000.
Not surprisingly, deaths from flu were highest in those older than 70 years. The highest rate of deaths for all ages was in Eastern Europe.
Regarding hospitalizations, the team estimated that flu accounts for 9,459,000 (95% CI, 3,709,000–22,935,000) each year and that of all LRTIs, flu is linked to 11.5% of episodes, which reflects 54,481,000 illnesses (95% CI, 38,465,000–73,864,000), about 8,172,000 of them severe infections (95% CI, 5,000,000–13,296,000).
"Although preparedness planning will be important for potential pandemics, health loss due to seasonal influenza LRTIs should not be overlooked, and vaccine use should be considered. Efforts to improve influenza prevention measures are needed," the authors concluded.
Dec 12 Lancet Respir Med abstract
Study: Stockpiled H5N1 vaccine shows no drop in immunogenicity
H5N1 vaccine that has been stored in the nation's Strategic National Stockpile since 2005 is still safe and immunogenic, according to a study published yesterday by researchers from the US Department of Health and Human Services (HHS) Biomedical Advanced Research and Development Authority (BARDA) and collaborators at St Jude Children's Hospital in Memphis.
In a blog post today, BARDA said in 2015 it asked researchers to conduct clinical trials to assess antigen against the H5N1 influenza A/Vietnam/1203/2004 strain that has been stored since 2005 and MF59 adjuvant that had been in the stockpile for more than 5 years. The team assessed the immunogenicity of two doses of the inactivated monovalent vaccine in people ages 18 to 64, an age group that would likely comprise healthcare workers and frontline responders in a pandemic setting.
The stockpiled pre-pandemic vaccine was well-tolerated, with or without the adjuvant. Participants experienced routine injection-site soreness or redness, but no serious adverse events were reported. No drop in immunogenicity was seen, even in the oldest stockpiled vaccine. As expected, the adjuvanted vaccine was linked to a greater immune response compared the unadjuvanted version, and the stockpiled H5N1 vaccine prompted cross-reactive antibody responses, signaling the potential to prevent infections against other H5N1 strains.
BARDA said the results from the study are useful for its ongoing work to assess prime-boost pandemic vaccination strategies.
Dec 12 Vaccine abstract
Dec 13 ASPR blog post