The huge value of vaccinating more children and young adults for influenza is being seriously underestimated, experts say in a new report.
In a computer modeling analysis published in the journal Vaccine, the experts supported by the National Institutes of Health, question the conventional wisdom of focusing vaccine programmes on the elderly and those at higher risk of death and serious complications.
The study suggests that children in school and young adults at work do the vast majority of flu transmission. Programs that effectively increase vaccination in those groups would have the best payoff, the research concluded.
The key message they say is that “If you don't catch the flu, you can't die from it”. Breaking the cycle of transmission benefits everyone from infants to the elderly, the researchers claim.
"In most cases, the available flu vaccine could be used more effectively and save more lives by increasing the number of vaccinated children and young adults," said Jan Medlock, a co-author of the study and researcher with the Department of Biomedical Sciences in Oregon State University's College of Veterinary Medicine.
"That approach could really limit the cycle of transmission, preventing a great deal of illness while also reducing the number of deaths among high risk groups," he said. "Approaches similar to this were used in Japan several decades ago, and they accomplished just that. Our new analysis suggests we should reconsider our priorities for vaccination."
In a perfect world and in accord with recommendations from America’s Centers for Disease Control and Prevention, researchers agree that almost everyone over the age of six months should get the flu vaccine, unless they were allergic or had other reasons not to take it. But in the United States, only about one-third of the population actually gets a flu vaccine each year. Historic efforts have been focused on people at higher risk of death and severe disease – often the elderly, and those with chronic illness, weakened immune systems, health care workers or others. This is similar to the UK approach.
Seasonal influenza in the US results each year in an average of 36,000 deaths, more than 200,000 hospitalisations, an $87 billion economic burden, and millions of hours of lost time at school and work.
In the US, the flu vaccine up until 2000 was only recommended for people over 65, Medlock said, and other age groups were added in the past decade as it became clear they also were at high risk of death or complications – children from age six months to five years, and adults over 50. Just recently, age was taken completely out of the equation.
In the UK it has now been recommended that all children between 2 and 17 have an annual flu vaccine but this won’t be offered to them on the NHS until 2014.
"Clearly we would want people at high medical risk to get a flu vaccine as long as it is abundant," Medlock said. "But what we're losing in our current approach is the understanding that most flu is transmitted by children and young adults. They don't as often die from it, but they are the ones who spread it to everyone else."
The population and disease transmission modeling done in the new study outlines this, and concluded that a 25-100% reduction in deaths from flu or its complications could be achieved if current flu vaccine usage were shifted to much more heavily include children and young adults, as well as those at high risk.
"Vaccinating children could prevent a great deal of illness and save many lives at all ages, not just the children," concluded the authors, "More aggressive educational campaigns to reach young adults would also be helpful."