Authors: Martha Powell, Future Science Group
How successfully an individual can fight flu could be influenced by the strain first encountered during childhood, according to new research. The findings could help to explain why individuals react differently to the same strain of flu virus.
It has previously been unclear why one strain of flu can cause illnesses of different severity in different people; however, in 2016 a research team discovered that past exposure to the flu virus determines an individual’s response to subsequent infections – termed immunological imprinting.
In the current study this group aimed to assess whether immunological imprinting could explain people’s response to circulating flu strains and the discrepancies seen between different age groups.
To do this the researchers analyzed health records routinely obtained from hospitals and private physicians to track flu cases, assessing how different strains affected different age groups in the cohort. They discovered that individuals first exposed to H1N1 during childhood were less likely to end up in hospital if they encountered this strain again, compared with individuals first exposed to H3N2. On the other hand, the team observed that individuals first exposed to H3N2 had extra protection against this strain later in life.