Sentences with phrase «circulating strains change»
It is well - established that influenza vaccines are less effective in «mismatched» seasons when the main circulating strains change after the months - long vaccine production process has already begun.
https://www.sciencedaily.com/ Not exact matches
In some cases, the mutations produced the same amino acid change in both the cancer patients» and the global virus strains circulating after 2010.
The findings, which appear in the March 11 issue of Cell Host & Microbe, contradict previous reports from Indian health officials that the strain has not changed from the version of H1N1 that emerged in 2009 and has been circulating around the world ever since.
The vaccine used during the 2012 — 13 flu season in Canada did not work very well, despite the fact that the circulating flu viruses had not seemingly changed much after the vaccine strains had been chosen.
Changes to the flu strains circulating around the Northern Hemisphere explain why last year's flu vaccine didn't work so well.
So, due to natural changes in the virus as it evolves, as well as due to mutations that may be caused by growing the vaccine strain, the circulating virus and the vaccine become less well matched over time.