CDC: Flu vaccine reduced kid’s risk of ICU flu admission by three-fourths

Influenza vaccination reduced children’s risk of pediatric intensive care unit (PICU) admission for flu by three-fourths during 2010 to 2011 and 2011 to 2012, according to a Centers for Disease Control and Prevention (CDC) study published online March 26 in the Journal of Infectious Diseases.

In an observational, case-control study,  the CDC's Influenza Division and colleagues studied children admitted to 21 US PICUs with severe respiratory illness during the 2010 to 2011 and 2011 to 2012 flu seasons. There were 216 children aged 6 months to aged 17 years enrolled. All children had RT-PCR testing for flu. Children with RT-PCR-confirmed flu-positive infections were “cases;” those without flu were “PICU controls.” A secondary set of 93 “community controls” was made up of children who had similar flu exposure and underlying medical conditions as cases.

The researchers searched medical and immunization records to validate vaccination. Vaccine effectiveness was estimated using logistic regression models by comparing cases with PICU controls and community controls and controlling for potential confounders.

Of the children in the study, 44 tested positive for influenza, and 172 were influenza-negative controls. Fifty-five percent of the children who came down with life-threatening flu had at least 1 underlying chronic medical condition that placed them at higher risk of complications. The study found low vaccination rates among the kids hospitalized for flu, only 18% of them had been fully vaccinated against the flu; 39% of the ICU controls and 51% of community controls had received flu shots.

“It is important for children to be vaccinated against influenza viruses each season to reduce the risk of influenza-related complications,” said Dr Alicia Fry from CDC's Influenza Division.

Flu causes hospitalizations in children each season, with CDC estimating that 20,000 children younger than 5 years are hospitalized with flu on average each year.

All children aged >6 months are recommended to receive annual flu vaccination, according to Dr Fry.

“This is especially important in child at high risk of developing influenza-related complications [eg, children younger than aged 5 years old, especially younger than aged 2 years, and children of any age with certain chronic medical conditions such as asthma, diabetes, or neurologic or developmental delays, are at high risk of serious flu complications],” Dr Fry said.

“However, these and other studies indicate that some vaccinated persons will become infected with influenza despite having been vaccinated,” she continued. “Therefore, clinicians and the public are reminded of CDC’s influenza antiviral treatment recommendations. Antiviral medications should be used as recommended for treatment in patients, regardless of vaccination status.  If a child has symptoms suspicious for flu and they are hospitalized or have a condition that puts them at high risk of developing flu-related complications, they should receive empiric antiviral treatment as soon as possible.”

Parents of children at high risk for flu-related complications should seek treatment from a healthcare provider as soon as possible, if their child is ill during the flu season.