The efficacy of this year's influenza vaccine has been reported to be lower in South America than the last, according to the Centers for Disease Control and Prevention. The health body is now taking clues from this on how much protection the shots would give to people in the US this year. The success of the annual vaccine was 34.
5 per cent against hospitalization, according to interim estimates from CDC's Morbidity and Mortality Weekly Report, among high-risk groups like young children, those with underlying health conditions, and older adults. This means that vaccinated people in these two groups were less likely than unvaccinated people to get sick enough to go to the hospital. Last year, the CDC had estimated that vaccine potency in South America was 51.
9 per cent against hospitalization among at-risk groups. According to studies, from 2013 to 2017 estimated effectiveness was around 43 per cent for fully vaccinated young children and 41 per cent for older adults. Every year, scientists update the flu vaccine based on their estimate about what formula will be a good match against a constantly evolving virus.
The data was consolidated from South American nations including Argentina, Brazil, Chile, Paraguay, and Uruguay. Why has the flu vaccine efficacy come down? Experts say the drop in potency of the vaccine could be due to fewer cases from the A(H1N1) pdm09 - a strain that has spread since the H1N1 swine flu pandemic in 2009. In the past, flu vaccines have usually done bet.