Effectiveness and Impact of the 4CMenB Vaccine against Group B Meningococcal Disease in Two Italian Regions Using Different Vaccination Schedules: A Five-Year Retrospective Observational Study (2014–2018)
Chiara Azzari,
Maria Moriondo,
Francesco Nieddu,
Valentina Guarnieri,
Lorenzo Lodi,
Clementina Canessa,
Giuseppe Indolfi,
Mattia Giovannini,
Giuseppina Napoletano,
Francesca Russo,
Tatjana Baldovin,
Silvia Cocchio,
Silvia Ricci,
Vincenzo Baldo
Affiliations
Chiara Azzari
Section of Pediatrics, Department of Health Sciences, University of Florence, Viale Pieraccini 24, 50139 Florence, Italy
Maria Moriondo
Section of Pediatrics, Department of Health Sciences, University of Florence, Viale Pieraccini 24, 50139 Florence, Italy
Francesco Nieddu
Section of Pediatrics, Department of Health Sciences, University of Florence, Viale Pieraccini 24, 50139 Florence, Italy
Valentina Guarnieri
Section of Pediatrics, Department of Health Sciences, University of Florence, Viale Pieraccini 24, 50139 Florence, Italy
Lorenzo Lodi
Section of Pediatrics, Department of Health Sciences, University of Florence, Viale Pieraccini 24, 50139 Florence, Italy
Clementina Canessa
Section of Pediatrics, Department of Health Sciences, University of Florence, Viale Pieraccini 24, 50139 Florence, Italy
Giuseppe Indolfi
Immunology and Molecular Microbiology Unit, Meyer Children’s Hospital, Viale Pieraccini 24, 50139 Florence Italy
Mattia Giovannini
Section of Pediatrics, Department of Health Sciences, University of Florence, Viale Pieraccini 24, 50139 Florence, Italy
Giuseppina Napoletano
Prevention Department, Veneto Regional Health Authority, via Don Tosatto 147, 30174 Venice Mestre, Italy
Francesca Russo
Prevention Department, Veneto Regional Health Authority, via Don Tosatto 147, 30174 Venice Mestre, Italy
Tatjana Baldovin
Department of Cardiac Thoracic Vascular Sciences and Public Health, Public Health Section, University of Padua, via Leonardo Loredan 18, 35131 Padua, Italy
Silvia Cocchio
Department of Cardiac Thoracic Vascular Sciences and Public Health, Public Health Section, University of Padua, via Leonardo Loredan 18, 35131 Padua, Italy
Silvia Ricci
Section of Pediatrics, Department of Health Sciences, University of Florence, Viale Pieraccini 24, 50139 Florence, Italy
Vincenzo Baldo
Department of Cardiac Thoracic Vascular Sciences and Public Health, Public Health Section, University of Padua, via Leonardo Loredan 18, 35131 Padua, Italy
Background: A few years after the introduction in Italy of a four-component anti-meningococcal B vaccine (4CMenB), we evaluated the effectiveness and impact of vaccination in two regions using different schedules (2, 4, 6, 12 months in Tuscany vs. 7, 9, 15 months in Veneto) through an observational retrospective study. Methods: Vaccination started in 2014 in Tuscany and in 2015 in Veneto; the data collected referred to the period 2006–2018 for Tuscany and 2007–2018 for Veneto. Cases of invasive meningococcal disease due to N. Meningitidis B were identified by culture and/or real-time PCR. Results: In Tuscany, pre-vaccine incidence was 1.96 (95% CL 1.52; 2.40) and dropped to 0.62 (95% CL 0.60; 0.64) in the post-4CMenB era. Evaluating only vaccinated children, post-4CMenB incidence was 0.12 (95% CL 0.08; 0.15). In Veneto pre-vaccine incidence was 1.94 (95% CL 1.92; 1.96) and dropped to 1.34 (95% CL 1.31; 1.38) in the post-4CMenB era. In the vaccinated population, MenB incidence was 0.53 (95% CL 0.50; 0.56). Vaccine effectiveness was 93.6% (95% CL 55.4; 99.1) in Tuscany and 91.0% (95% CL 59.9; 97.9) in Veneto, with mean vaccine coverages of 83.9% and 81.7%, respectively. The overall impact (evaluating both vaccinated and unvaccinated children) was 0.68 (95% CL 0.10; 0.89) in Tuscany and 0.31 (95% CL −0.56; 0.69) in Veneto; the total impact (evaluating only vaccinated children) was 0.94 (95% CL 0.56; 0.99) and 0.90 (95% CL 0.57; 0.97), respectively. The relative case reduction (RCR) was 65% in Tuscany and 31% in Veneto. Considering the vaccinated population, the RCR was equal to 91% and 80%, respectively. Conclusion: In conclusion, 4CMenB appears to have a very high effectiveness in Italy; the impact of vaccination appears greater where the immunization program is started early.
