What this Trial Is About

Streptococcus pneumoniae is responsible for serious infections associated to numerous hospitalizations and high rate of mortality. The incidence and therefore the burden of pneumococcal infections have been significantly reduced thanks to the use of pneumococcal conjugate vaccines (PCVs). PCVs were shown to be effective against vaccine-type serotypes causing both non-invasive and invasive pneumococcal diseases (IPD) in children and adults. PCVs use in children was shown to have an impact on IPD incidence among adults due to herd immunity and on antimicrobial resistance. To increase the protection of at-risk patients against IPD, the 20-valent PCV (PCV-20) is recently recommended in adults, after a period where PCV-13 followed by pneumococcal polysaccharide vaccine 23 valent (PPV-23) was recommended. PCV-20 effectiveness against IPD and against pneumonia was inferred from immunobridging with PCV-13. Indeed PCV-13 was shown effective to reduce the incidence of low respiratory tract infections and IPD (bacteraemia and meningitis) in 65-years-old-adults and older. Currently immunization against S. pneumoniae is recommended with PCV-20 for adult patients at-risk for IPD such as immunocompromised (=high-risk patients) and in immunocompetent people with underlying chronic conditions (cardiovascular, liver, pulmonary, kidney diseases and diabetes mellitus) (=medium risk patients). However, vaccine coverage against IPD in adults remains low globally, and does not exceed 5 % in France. Reducing missed opportunities of vaccination for S. pneumoniae is crucial.

Immunogenicity and Safety PCV-20 of the Vaccine Administered During an Acute Febrile Illness in Adults