researchers at mcmaster university have found that children who receive years of season-specific flu vaccines develop antibodies that also provide broader protection against new strains, including those capable of causing pandemics.
the same ability does not exist in adults.
the findings, reported today in the journal cell reports medicine, could inform the design of a universal influenza virus vaccine for children, who are especially vulnerable to serious complications from flu, such as pneumonia, dehydration and, in rare cases, death.
“little is known about how seasonal flu vaccination impacts the immune responses in children, who are a major source of flu transmission and a very high-risk group,” explains matthew miller, lead author of the study and associate professor at the michael g. degroote institute for infectious diseases research.
“understanding how seasonal vaccination and different vaccine formulations shape childhood immunity is critical for effective prevention.”
children and adults are fundamentally different in their immune responses to influenza virus, explains miller, whose lab is part of
mcmaster’s global nexus for pandemics and biological threats. unlike small children, most adults have been infected with and vaccinated against flu many times throughout their lives.
“when we give adults vaccines, they make a very specific immune response against seasonal strains,” says miller.
“adults simply don’t generate immune responses to seasonal flu vaccines capable of protecting them from pandemic viruses like children can.”
the researchers spent three years studying immune responses in children between the ages of 6 months and 17 years. they found that as the children grew older, they became less capable of producing broadly protective antibodies, because of their repeated exposure to influenza, through infection or vaccination.