Flu Vaccination Reduces Hospitalizations in Children

A new study shows that children vaccinated against influenza are significantly less likely to experience serious complications that require hospitalization.

Researchers at the University of Toronto (Canada), Public Health Ontario (Toronto, Canada), and other institutions conducted a study to estimate influenza vaccine effectiveness in 9,982 children (6–59 months of age) hospitalized over four seasons, of who 12.8% tested positive for influenza. The researchers then compared children who were fully vaccinated, partially vaccinated, and those who were not vaccinated at all, and also compared variations by age group and circulating influenza strains per season.

The results revealed that over the combined four seasons, vaccine effectiveness was at 60% for the full vaccination and 39% for a partial vaccination. When analyzed by age, fully vaccinated children aged two to four years of age saw their risk of hospitalization due to influenza drop by 67%, while those aged six to 23 months saw risk drop by 48%. Even for children who were partially vaccinated against influenza--such as those who received one dose of influenza vaccine during their first influenza season--the risk of hospitalization dropped by 39%. The study was published on November 17, 2017, in PLOS One.

“These results show that flu vaccines are effective at preventing influenza hospitalizations in young kids, and this extended to those who received their vaccination in two consecutive seasons,” said lead author PhD candidate Sarah Buchan, MSc, of the University of Toronto. “This contributes to the evidence that this group should be receiving their seasonal vaccine annually to prevent such serious outcomes.”

Influenza spreads around the world in a yearly outbreak cycle, resulting in about three to five million cases of severe illness and about 250,000 -500,000 deaths. In the Northern and Southern parts of the world outbreaks occur mainly in winter, while in areas around the equator outbreaks may occur at any time of the year. Death occurs mostly in the young, the old, and those with co-morbidities. In the 20th century, three influenza pandemics resulting in millions of deaths occurred: Spanish influenza in 1918, Asian influenza in 1958, and Hong Kong influenza in 1968.

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University of Toronto
Public Health Ontario