A debate in the US may soon swing in favor of recommending universal influenza vaccination for all babies aged 6 months and upwards, and could coincide with the licensing of a live vaccine that avoids the use of needles.

US experts are keeping a close watch on Ontario which, in 2000, became the only region in the world to introduce such a program, according to David Fedson, of Aventis Pasteur in France, who presented the case for universal vaccination today.

For more than 20 years, epidemiologists have gathered a growing body of data showing that influenza vaccination is effective, said Fedson. It reduces hospitalisations of young children with flu-related illnesses including secondary middle-ear infections, and lowers death rates among people aged over 65, from conditions exacerbated by 'flu, including heart disease and diabetes.

A recent Japanese study, in particular, demonstrated that vaccinating school-aged children leads to a reduction in winter season mortality in the elderly, he noted. This is consistent with the view that children are the primary initiators of household outbreaks and in the community.

US health officials currently recommend that 'flu vaccines be given to the elderly and to at-risk groups, including children with chronic conditions such as asthma, cystic fibrosis, chronic heart disease, renal diseases and malignancies.

A second debate, about the type of vaccine to use, is likely to follow, said Fedson. The choice is between the traditional inactivated, injectable form and a new, live attenuated influenza vaccine (LAIV), which can be squirted up the nose. Fedson predicts that one LAIV, still awaiting FDA approval, will be licensed for the first time within the next year.

"The LAIV, if it's not so horribly expensive, will be fabulous in terms of administration," said Fedson. "You can have paramedics squirt the stuff in children's noses in day-care centers and school classrooms," he noted.

"And of course in pandemic situations you can immunize populations very quickly with a non-injectable vaccine," Fedson said. This approach would also avoid the risks of transmission of blood-borne pathogens such as hepatitis B and C, he added.

But the introduction of LAIV will not be a smooth one, however, as opponents may well argue the lack of long-term safety information, Fedson noted.

"Because it's a live vaccine you're going to have the anti-vaccination community come out of the woodwork, and say 'here's another vaccine that's going to cause side-effects, and they want us to give this to our children every year, not just once or twice.'"

However, he insisted, the new vaccine's efficacy is "stunning."