Vaccination works

Here is the rate of systemic infections caused by the bacteria Streptococcus pneumococcus (aka pneumococcus or strep pneumo) before adn aftern immunization for it. Not cases are only by those serotypes covered by the vaccine. The <5 is the group that actually got the vaccine, but there seems to be a decrease of disease in each age group, presumably because older people get it from kids. The incidence is so high in the elderly because they tend to be frail to begin with