Study found increase in RSV-associated hospitalizations in premature babies in N.S.

A new study is showing a policy change in 2016 related to the vaccination of some premature babies for RSV in Nova Scotia led to a tenfold increase in the number of infants in that group that were hospitalized with the respiratory virus.

The policy was reversed in 2023. Halifax pediatric infectious disease physician Joanne Langley said the study shows why it's crucial to examine the effects of policy changes and to prevent infants from contracting RSV.

"We wanted to make sure that there weren't a lot of children that would be harmed by that policy," said Langley, who led the study. "And what we found is that there was a much higher number of admissions when we restricted access to the antibody."

RSV, which stands for respiratory syncytial virus, is a common and highly contagious respiratory infection that is especially dangerous to infants and older people.

Up until 2016, babies in Nova Scotia born at 32 weeks gestation or less were eligible for palivizumab, a vaccine administered in four or five doses in an RSV season.

But that year, the IWK children's hospital in Halifax dropped that eligibility down to 30 weeks and under, in line with Canadian Paediatric Society recommendations at the time.

'You feel helpless'

Langley's team examined that two-week change to eligibility using provincial databases. In a study published this month, they found hospitalizations linked to RSV in Nova Scotia spiked in premature infants born at 30 to 32 weeks gestation between 2016 and 2019. There were no deaths.

In 2023, the IWK policy reverted to 32 weeks gestation and under. This season, a new vaccine called nirsevimab was introduced in Nova Scotia. It too is restricted to babies born within 32 weeks gestation, along with infants with high-risk health concerns such as congenital heart disease.

However, nirsevimab is now available for all babies in Ontario and Quebec. That's the kind of universal program Carye Leighton wants in Nova Scotia.

Her two daughters, including one born at 32 weeks gestation in 2017, contracted RSV as babies and were hospitalized. Neither had been eligible for an RSV vaccine.

"It's scary. You feel helpless. There's not much you can do as a parent," said the Halifax mother. "You'll start to see them kind of gasping. You're seeing their collarbone a little bit and then on the ribcage as well, like they're struggling to breathe."

A spokesperson for the Department of Health said the province is reviewing an expansion of its publicly funded program for premature infants.

"We are currently reviewing the publicly funded immunization program and considering opportunities to expand it to ensure the best program for all Nova Scotians," the spokesperson said.

The Canadian Paediatric Society said its most recent recommendation is to offer nirsevimab to all infants.

A spokesperson said in an email that the society recommended in 2015 that the cut-off for the old vaccine, palivizumab, be reduced because it "did not appear to be cost-effective" for babies born at 30 to 32 weeks gestation.

"One could have predicted that the number of admissions would increase due to this policy; the increase in Nova Scotia was perhaps higher than expected, possibly because the sample size is relatively small," wrote the spokesperson.

Fabiana Bacchini, executive director of the Canadian Premature Babies Foundation, said providing access to the RSV vaccine for all infants is better than allowing children to get sick and require medical attention.

"We're talking about financial savings for the health-care system, but also for a family perspective. We know how hard it is for families to have those babies back in the hospital," said Bacchini.

In Nova Scotia, people 60 years and older living in long-term care or awaiting long-term care placement are eligible to receive an RSV vaccine for free. A pregnant person in their third trimester can pay out-of-pocket for a vaccine that would also protect their infant.