One of my residents in clinic pointed me to some new research on the flu vaccine. “Effectiveness of influenza vaccine against life-threatening RT-PCR-confirmed influenza illness in US children, 2010-2012“:
Background. No studies have examined the effectiveness of influenza vaccine against ICU admission associated with influenza virus infection among children.
Methods. In 2010-11 and 2011-12, children aged 6 months to 17 years admitted to 21 US pediatric intensive care units (PICUs) with acute severe respiratory illness and testing positive for influenza were enrolled as cases; children who tested negative were PICU controls. Community controls were children without an influenza-related hospitalization, matched to cases by comorbidities and geographic region. Vaccine effectiveness was estimated with logistic regression models.
Researchers investigated two seasons of flu to look at kids admitted to 21 pediatric intensive care units with really bad influenza. They compared them to kids admitted to the PICU with no influenza and to kids who didn’t get hospitalized at all. Overall, there were 44 cases, 172 PICU controls, and 93 community controls.
Of the children who were admitted to the PICU for influenza, only 18% were vaccinated. About a third of the PICU controls were vaccinated. More than half of the non-hosiptalized children were vaccinated. A child who was vaccinated was 74% less likely to be admitted to the PICU for influenza than children who were not vaccinated.
We’re talking about life-threatening illness here. Granted, we’re also talking about rare outcomes, and kids with other chronic conditions are more susceptible. But every time I hear someone complain (without evidence) that the flu vaccine “doesn’t work anyway”, I get a bit frustrated.