The purpose of this study is to learn about the safety of 20-valent Pneumococcal Conjugate Vaccine (PREVENAR 20) under actual clinical practice in Japan.

This study is seeking for infants aged between two months to six months who are vaccinated with PREVENAR 20 for the first time.

Infants aged between two months and six months are normally given four vaccinations. The first three vaccinations are called primary vaccinations and are given with an interval of one month between each vaccination. The fourth vaccination is called the booster and is given between 12 and 15 months of age.

Participants will take part in this study from the day of first vaccination to 28 days after fourth vaccination.

The side effects observed in the participants will be recorded and looked into.

Inclusion Criteria:

1. Infants aged 2 months, inclusive, to 7 months, exclusive
2. Those without a history of pneumococcal vaccination including PREVENAR 20
3. Those who are expected to receive 4 doses
4. Those whose parent or legal guardian understands the details of the study and provides consent to provision of information collected in the study to third parties and use of the information for other purposes.

Exclusion Criteria:There are no exclusion criteria for this study.

Infants aged 2 months, inclusive, to 7 months, exclusive who PREVENAR 20 for the first time.

Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical\_trials/trial\_data\_and\_results/data\_requests.