A two-phases study will be carried out with the following aims

1. st phase (2018-2020)

   • To investigate the vaccination coverage for Rotavirus vaccine (RV) in Campania Region together with other pediatric vaccinations scheduled in the first 12 months of life: hexavalent, pneumococcal conjugate (PCV), meningococcal B (MenB)
   • To collect data on appropriate timing of the 3 doses of human bovine pentavalent reassortant vaccine (RV5) administration
   • To evaluate the frequency of a co-administration of RV5 with other vaccines scheduled in the first 12 months of life (hexavalent/PCV+RV5, MenB+RV5 vs RV5 alone) and assess the variability in co-administration rates according to RV5 dose

2. nd phase (2020-2022)

   • To investigate the effect of Coronavirus-Disease-19 (COVID-19) pandemic on vaccination coverage in the first year of life, focusing on RV vaccination
   • To investigate the effect of COVID-19 pandemic on timing of vaccine administration in the first year of life, focusing on those vaccines without catch-up vaccination schedule (i.e. RV)

Hypothesis are the following:

• Vaccination coverage and timing of vaccines scheduled in the first year of life are not fully aligned with what is established by the Italian National Prevention Plan 2017-2019
• Co-administration of RV5 and MenB in comparison with other coadministration e.g. hexavalent/PCV is lower
• Co-administration of RV5 and MenB allows to ensure appropriate timing of RV vaccination schedule
• COVID-19 pandemic may have affected the overall vaccination coverage as well as the timing of selected vaccination scheduled in the first year of life, with a more relevant impact on vaccines for whom a catch-up vaccination schedule is not feasible, such as RV immunization.

The study will be carried out in collaboration with eight Vaccination Centers, which are responsible in Italy for the organization and delivery of vaccination as well as for overseeing implementation of vaccinations and monitoring coverage, in four provinces of Campania Region (representative of different regional areas) with the following aims:

• To investigate the vaccination coverage for Rotavirus vaccine (RV) in Campania Region together with other pediatric vaccinations scheduled in the first 12 months of life: hexavalent, pneumococcal conjugate (PCV), meningococcal B (MenB)
• To collect data on appropriate timing of the 3 doses of human bovine pentavalent reassortant vaccine (RV5), which is the most used RV vaccine in Campania Region.
• To evaluate the frequency of a co-administration of RV5 with other vaccines scheduled in the first 12 months of life (hexavalent/PCV+RV5, MenB+RV5 vs RV5 alone) and assess the variability in co-administration rates according to RV5 dose
• To investigate the effect of Coronavirus-Disease-19 (COVID-19) pandemic on vaccination coverage and on timing of vaccine administration in the first year of life, focusing on RV vaccination

The study consists of two parallel phases:

1. First phase aimed at enrolling children who received a vaccine in first 12 months of life between January 2018 and December 2020. These data would provide informative data about the pre-pandemic situation and the impact of restrictive measures against COVID-19 on vaccination.
2. Second phase, enrolling children aged between 6 weeks to 12 months who will enter the national Immunization schedule according to the Italian Immunization Plan up to June 2022 (cohort 2021), in order to investigate a possible role of COVID-19 pandemic and new strategies applied at local level for a catch-up vaccination in the first year of life.

A specific digital dataset will be created to collect data about the number of eligible children who received vaccinations in the territory of each Vaccination Center during the study period. The rough data will be extrapolated by an investigator for each Vaccination province through a single chart reviewing from the regional vaccination database. The regional electronic immunization register is currently used for the entire immunization process (from vaccination call-out, to calculating the vaccination coverage, up to send aggregated data to the Ministry of Health in order to estimate the national vaccination coverage).

The characteristics of each vaccine administered will be recorded (i.e. brand, number of doses) as well as the lass of time between vaccination and possible delay.

Anonymized data obtained by the Regional Registry will be used to analyze vaccination coverage according to age and cohort, timing of administration and frequency and type of co-administration.

Hypothesis are the following:

• Vaccination coverage and timing of vaccines scheduled in the first year of life are not fully aligned with what is established by the Italian National Prevention Plan 2017-2019
• Co-administration of RV5 and MenB in comparison with other coadministration e.g. hexavalent/PCV is lower
• Co-administration of RV5 and MenB allows to ensure appropriate timing of RV vaccination schedule
• COVID-19 pandemic may have affected the overall vaccination coverage as well as the timing of selected vaccination scheduled in the first year of life, with a more relevant impact on vaccines for whom a catch-up vaccination schedule is not feasible, such as RV immunization.

Inclusion Criteria:

• all children receiving vaccination according to the Italian National Vaccine Prevention Plan 2017-2019

Exclusion Criteria:

• primary outcomes data missing.

children receiving vaccination in their first year of life at one of the Vaccination Centers involved in the study