Scientists have found that children who receive the seasonal flu vaccine for years produce antibodies that also provide them with greater protection against new strains, including those that can cause a pandemic.
Annual flu vaccination in children strengthens their future immunity
Published Feb. 4, 2022 12:57
Thinkstock/GettyImages
A finding, published in the journal Cell Reports Medicine, could help develop a universal flu vaccine for children who are particularly prone to serious complications from influenza, such as pneumonia, dehydration, and even - in extreme cases - death.
"Little is known about the effects of seasonal influenza vaccination on the immune response in children, who are the primary transmitters of influenza and a very high-risk group," explains Matthew Miller, study lead author and assistant professor at Michael G. DeGroote Institute for Infectious Diseases Research. "Understanding how seasonal immunization and different vaccine formulations shape children's immunity is critical to effective prevention."
Children and adults have fundamentally different immune responses to the flu virus, explains Miller, whose lab is part of McMaster's Global Nexus for Pandemics and Biological Threats.
"When we give vaccines to adults, they elicit a very specific immune response against seasonal strains," says Miller. "Adults simply do not develop an immune response against seasonal flu that can protect them against pandemic viruses as they do in children."
Researchers spent three years studying immune responses in children aged 6 months to 17 years. They found that as children grew older, they became less able to produce broad-spectrum antibodies.
While COVID-19 measures such as distancing and masking have also reduced flu cases, Miller warns that the flu will return, possibly in dangerous forms.
Flu has caused five pandemics in the past 100 years. The Spanish flu in 1918-19 killed around 50 million people worldwide, while the global population was just 1.8 billion - just under a quarter of the current population.
As part of the study, researchers also compared two forms of vaccine: a conventional flu vaccine and a nasal spray vaccine that acts on the upper respiratory tract where infection begins.
Both worked equally well in producing broad-spectrum antibodies, which is good news for parents looking for a painless alternative to needles.
"This is an important discovery because it means we have flexibility in what kind of vaccines we can use to create a universal vaccine for children. We now know that children's immune systems are much more flexible than adults' immune systems in terms of being able to teach them to perform these wide-ranging protective responses, ”says Miller.
Source: ScienceDaily
