Mutation has allowed some flu viruses to beat the flu vaccine. Researchers found out that mutilations in a specific region of H3N2 viruses decreased the effectiveness of these antibodies, making last year’s flu shot null and void for the next year. In light of this manufacturers need to regularly upgrade their formulations.
Recommendations came from the WHO (World Health Organization) to appropriately upgrade the flu vaccine for the next season. The 2014-2015 ineffectiveness of flu vaccines was attributed to these new mutations. Based on a complete analysis of the strains of flu, those are most predominant at present, new vaccines are being devised that target different areas of the flu virus.
When the researchers initially developed the vaccine, for the last season, they dint account for the mutation of the influenza viruses in circulation. Researchers at the Wistar Institute in Philadelphia, thought the Texas strain would predominate through the winter, but instead three other H3N2 varieties surged.
Hensley and colleagues created a lab version of the Texas strain as their standard of comparison, to research the matter fully.
The researchers looked at what went wrong with the H3N2 strain by playing with variations of the virus and a key protein called hemagglutin, which helps the infection stick to our cells.
Vaccines are developed to protect us from illnesses by producing antibodies that bind to viruses.
Matching viruses to vaccines is a difficult task.
The findings published in the journal Cell Reports show that last year’s vaccine was 75 percent less effective than Hensley’s new vaccine at initiating an immune response against the mutated H3N2 flu strain.
During a study conducted, scientists took blood samples from people who had been immunized with the 2014-2015 flu shot and discovered that the strain that contained a stealthy mutation made it difficult for antibodies to pick up on the virus.
Hensley and colleagues analyzed sera isolated from vaccinated humans, as well as infected ferrets and sheep, and they observed reduced hemagglutination inhibition and in vitro neutralization titers against viruses with mutations in the hemagglutinin site B.
Although so far it is not absolutely clear which mutations allowed the viruses to escape the vaccine.
In February experts are going to decide where to focus their efforts on next year’s vaccine.