With thousands of children under five hospitalised each year with RSV, experts want New Zealand to catch up with other countries and introduce a universal vaccination programme.

A new briefing from the Public Health Communication Centre has shown it could free up thousands of hospital beds each year.

RSV, or respiratory syncytial virus, is a common respiratory illness that causes lung and respiratory tract infections, with similar symptoms to a cold - but in young children, it can cause serious complications.

Lead author and paediatric infectious disease specialist Dr Hazel Dobinson said immunisation had transformed prevention overseas.

International evidence had shown immunisation programmes reduced hospitalisations from respiratory syncytial virus by up to 90 percent, easing winter pressure on health services and improving health equity.

In Australia, the ABC reported New South Wales are hailing a vaccination program that's nearly halved hospitalisations ahead of the winter peak as a "fantastic" success.

"We talk to our colleagues from overseas where these RSV prevention programs have been rolled out and they are just ecstatic," Dobinson said.

But New Zealand was yet to introduce a universal infant RSV prevention programme. About 200 infants were deemed high-risk each year, those with serious heart or lung conditions or born very prematurely, and received the palivizumab vaccine.

Each year, 1800 to 2000 children under five were hospitalised from the virus, with around half of those infants, Dobinson said.

Babies could develop bronchiolitis, struggle to breathe or feed, need oxygen or feeding tubes, and some required high-dependency or intensive care.

Māori and Pacific children, and children living in socioeconomically deprived and crowded households, were disproportionately affected.

The Briefing outlines two prevention strategies now being adopted internationally: long-acting monoclonal antibodies given to newborns, and maternal vaccination during pregnancy.

Studies had shown long-acting monoclonal antibodies reduced RSV-related hospitalisations by 70 to 90 percent, while maternal vaccination was around 70 percent effective at preventing severe RSV infections in infants up to six months of age.

Australia, the United Kingdom, the United States, Chile and much of Europe had already introduced infant RSV immunisation, maternal vaccination, or both, as part of their national immunisation programmes.

Dobinson said it could reduce bed block in places like Starship Hospital.

During the winter peak, "the Starship PICU [paediatric intensive care unit] doesn't accept and can't accept elective cardiac or other elective procedures that need an intensive care bed during the season because they just can't - they're full of RSV."

RSV already created a cost to the health system - hospital admissions, ED admissions, intensive care admissions, she said.

"And that's just the direct healthcare costs. We're not talking about the cost to families and the indirect costs. So it's millions of dollars that are already being spent for RSV disease and we've got something now to stop that."