Are you worried about catching the flu? New research suggests adults over the age of 30 only come down with the nasty virus about twice a decade.
A recent study found that while children get the flu about once every other year, this frequency significantly decreases with age, PLOS Biology reported. The findings suggest influenza is not as common as people generally think it is.
To make their findings a team of researchers looked at blood samples from volunteers in Southern China, which allowed them to assess antibody levels against nine different influenza strains between the years of 1968 and 2009.
"There's a lot of debate in the field as to how often people get flu, as opposed to flu-like illness caused by something else. These symptoms could sometimes be caused by common cold viruses, such as rhinovirus or coronavirus. Also, some people might not [realize] they had flu, but the infection will show up when a blood sample is subsequently tested. This is the first time anyone has reconstructed a group's history of infection from modern-day blood samples," said Adam Kucharski, who worked on the study at Imperial College London before moving to the London School of Hygiene & Tropical Medicine.
The researchers also developed a mathematical model of how our immunity to the flu virus changes over time. This model backed up past findings that suggested flu virus strains encountered earlier in life evoke stronger immune responses than those introduced in adulthood. The findings could help researchers gain insight into how population immunity influences viral evolution, helping them predict how different strains will behave in the future as well as how susceptible they will be to vaccines.
"What we've done in this study is to [analyze] how a person's immunity builds up over a lifetime of flu infections. This information helps us understand the susceptibility of the population as a whole and how easy it is for new seasonal strains to spread through the population," Kucharski concluded.
