Parental Refusal of Pneumococcal Vaccination Is Associated with An Increased Risk of Pneumococcal Related Hospitalizations in Children

Background:  Routine use of seven-valent pneumococcal conjugate vaccination (PCV7) has significantly reduced the incidence of invasive pneumococcal disease in the United States. Some parents, however, choose to decline or delay immunizations, in part, due the perception that the risks and severity of vaccine preventable diseases are low. The risk of invasive pneumococcal disease (IPD) and lobar pneumonia among children of parents who refuse PCV7 vaccine is unknown.

Objectives: To determine the association between a parental decision to decline or delay PCV7 vaccinations and the risk of hospitalization due to IPD and lobar pneumonia in children.

Methods: We conducted a nested case-control study within a cohort of children 2 mos.-5 years of age enrolled in Kaiser Permanente Colorado from October 2004-September 2009. Hospitalized cases of IPD and lobar pneumonia underwent medical record review. The cases were matched to non-diseased controls by age, sex and high-risk medical condition. We confirmed vaccination status of the cases and controls by medical records review. Children were classified as vaccine decliners, vaccine delayers or vaccine acceptors.  Data were analyzed with conditional logistic regression to calculate odds ratios (OR).

Results: We identified 106 cases of IPD and lobar pneumonia which were matched to 401 controls. In the cases, there were 6 (6%) vaccine decliners and delayers. In the controls, there were 4 (1%) vaccine decliners and delayers. Children of parents who declined or delayed PCV7 immunizations were 6.5-times (OR, 6.5; 95% CI, 1.7-24.5) as likely to be hospitalized for IPD or lobar pneumonia compared to vaccinated children.  In the entire pediatric population, 4.7% (95% CI, 0.0%-9.2%) of the cases were attributed to parents declining or delaying PCV7 immunizations.

Conclusions: Declining or delaying pneumococcal vaccination is associated with an increased risk for IPD and lobar pneumonia in children. Providers can use this important information when helping parents weigh the benefits and risks of immunizing their children.