Impact of pneumococcal polysaccharide vaccine in people aged 65 years or older
To the Editor: Menzies and colleagues promote the 23-valent polysaccharide pneumococcal vaccine (23vPPV) as effective in people aged 65 years or older.1 I believe their data show exactly the opposite. The vaccine appears to be ineffective.
In 2005, a nationally funded vaccination program began with 23vPPV for those aged ≥ 65 years and a 7-valent pneumococcal conjugate vaccine (7vPCV) for children. Subsequently, there was a rapid and dramatic drop in invasive pneumococcal disease in older people, but this was only for disease due to serotypes covered by the childhood 7vPCV. When the effects of the other components of the 23vPPV are examined, there is no fall but instead a statistically significant increase in invasive infections in older people.1
Vaccinating children with highly effective conjugated pneumococcal vaccines is associated with a dramatic decrease in invasive pneumococcal disease not only in children but also in older people. Older people benefit because vaccinated children carry fewer pneumococcal strains and thus pass on fewer invasive strains to parents and grandparents.2–4
I think that the only reasonable conclusion from the study by Menzies et al is that the non-conjugated vaccine is ineffective in those aged…