New Delhi: Age could be a dominant factor influencing how the body produces antibodies in response to viral infections, with different age groups targeting distinct parts of the same virus, according to a study published in Nature Immunology.

The research, led by scientists from the Institut Pasteur, found that individuals infected by the same virus can generate antibodies targeting different viral regions. Besides age, biological sex and genetic background were also found to influence both the quantity and specificity of antibodies produced.

Analysing data from the Milieu Interieur cohort of 1,000 healthy individuals, researchers observed that more than half of the antibody repertoire varied with age. For influenza strains H1N1 and H3N2, younger adults primarily produced antibodies targeting hemagglutinin — a rapidly evolving viral surface protein — while older adults targeted the more stable stalk domain.

The study also found sex-based differences, with women producing more antibodies against hemagglutinin compared to men. Genetic variations at specific immune-related loci were linked to differences in antiviral responses and, in some cases, autoimmune disease risk.

Researchers said the findings could help develop more personalised vaccines and treatments.