A postmarket safety comparison of 2 vaccination strategies for measles, mumps, rubella and varicella in Italy

Abstract

It is strategically important to monitor the safety profile of vaccination schedules in order to achieve and maintain high levels of coverage. We analyzed the cohort of individuals actively invited for measles, mumps, rubella and varicella (MMRV) vaccination in the Veneto region (north-east Italy) from 8/1/2013 to 7/31/2014, assessing the onset of adverse events (AE) relating to 2 different vaccination strategies for MMRV (MMR+V vs MMRV). During the vaccination session at 14 months old, parents were given a form for recording local and systemic reactions to vaccinations for 4 weeks afterwards. Overall, 12,288 forms were returned, and 84.6% of them were included in this analysis (5,130 relating to MMR+V and 5,265 to MMRV); 37.3% of the sample reported no AEs, with no difference between the 2 groups. Local reactions were more common in the MMR+V group (9.6% vs 2.9%; RR 3.33; 95% CI 2.79-3.98), while there was no difference in general reactions between the 2 groups (50% MMR+V vs 52% MMRV). The events most often reported were "fever <39.5°C," which was more frequently associated with the MMRV strategy (p<0.001), and "skin blotches and marks," which occurred more often in the MMR+V group (p<0.001). Reports of "fever ≥39.5°C" were equally distributed between the 2 groups. Sixteen cases of febrile seizures were reported (0.14% in the MMR+V group and 0.17% in the MMRV group). Similar safety profiles were identified for the 2 vaccination strategies. Although the method used to record reactions to vaccination demanded considerable resources, it enabled important information to be collected on parents' perception of the AEs occurring in response to their child's vaccination.

Adverse Events Following Measles-Mumps-Rubella-Varicella Vaccination and the Case of Seizures: A Post Marketing Active Surveillance in Puglia Italian Region, 2017–2018

“…Data of our study were consistent to literature findings. In a recent study published by Cocchio et al [44], fever was the most common systemic reaction after the MMRV vaccine, and the incidence of febrile seizure was 0.2%. Also, this study was based on active surveillance (then, the reporting rate was expected as higher) but causality assessment was not carried out, therefore we cannot evaluate the link between the vaccine and AEFIs [44,45].…”

Post-marketing surveillance of adverse events following measles, mumps, rubella and varicella (MMRV) vaccine: retrospecive study in apulia region (ITALY), 2009-2017

“…This study was based on active surveillance (than, the reporting rate was expected as higher) but causality assessment was not carried out, than we cannot evaluate the link between vaccine and AEFIs. 44 In a 2014 study on 3112 children, 10 febrile seizures were reported following MMRV administered alone or with other vaccines (rate: 3.21 × 1000 doses). Three of the seizures were reported by the investigator as related to vaccination (rate 1/ 1000 doses) and seven were reported as probably or definitely not related to vaccination: also, in this case, the authors did not use the WHO algorithm and it makes difficult to compare the results.…”

Seroprevalence to Measles Virus after Vaccination or Natural Infection in an Adult Population, in Italy

“…GMTs are shown above the population columns. P-value of the GMT between the first (1-11) and second(12)(13)(14) group is <0.05.…”

“…Since then, the attenuated varicella strain has been included in the formulation of the vaccine. This can be administered at the same session as trivalent anti-measles-mumps-rubella plus the monovalent anti-varicella vaccine or as quadrivalent MMRV combined vaccine [14].…”