Key Evidence: The introduction of PCV-10, along with a “catch-up” campaign for 1-4 year olds, led to dramatic reductions in the rates of pneumococcal pneumonia in adults (≥18 years old) in a rural area of Kenya with high rates of both adult pneumococcal pneumonia and HIV. Over five years following the vaccine introduction, the incidence rates among adults were 47-94% lower each year than in the pre-vaccine period, with similar declines for HIV-infected and HIV-uninfected adults.
Key Evidence: Children with cancer often rely on herd immunity as protection from vaccine-preventable diseases, so vaccinating family members and health workers is critical. Herd effects may be the only source of protection against diseases for which the vaccines are not recommended for immunosuppressed children, such as measles.