As the respiratory illness season begins, cases of respiratory syncytial virus (RSV) cases are rising in Canada. But a new tool — nirsevimab, a protective antibody for infants — offers hope for prevention, though it is currently available only in some provinces.
The latest data from Health Canada, covering the week of Nov. 24 to Nov. 30, shows RSV cases are already climbing, with infants under one year old making up the largest proportion of infections.
RSV is a common and highly contagious respiratory virus that typically causes mild symptoms, but in infants, it can lead to serious complications such as bronchiolitis and pneumonia, which may require hospitalization or even result in death, according to Health Canada.
Early infection has also been linked to long-term health issues, including persistent wheezing later in childhood.
“Respiratory syncytial virus can affect everyone, but more consistently, it severely affects children less than five years of age,” explained Dr. Darine El-Chaar, a maternal-fetal medicine physician at the Ottawa Hospital.
“A little baby has an immunity gap and doesn’t have the strongest immunity system to protect themselves, so they are more vulnerable and sensitive to get really sick,” she said.
Parents may be more aware of the dangers of RSV following the surge in infections two years ago, which occurred after COVID-19 lockdowns left some children unexposed to the virus and more vulnerable.
Nearly half (49.8 per cent) of RSV-related hospitalizations recorded in Canada from 2021 to 2022 were in patients under six months of age.
While last year’s respiratory illness season in Canada was less severe than the year before, RSV is still a serious threat, especially for infants.
That’s why health professionals, like el-Chaar, are relieved to have two treatment options available to protect infants this respiratory illness season — nirsevimab and Abrysvo (a vaccine given to pregnant people).