To be eligible for the main study, children in Yinzhou population-based EHR database must
be aged 1 to 24 months and receive at least one dose of 13vPnC between May 1st, 2017 and
July 24th, 2020 where the first dose is received before or on July 24th, 2020 since a 7-day
post-vaccination follow-up for each dose in each child receiving 13vPnC is needed. For the
prospective cohort in a sub-population of the main study, eligible children for the main
study must receive the first dose of 13vPnC between July 1st, 2018 and July 24th, 2020 and
an informed consent must be obtained from parents/legal guardians.
There are no exclusion criteria for this study.