[Immunization campaign with 13-valent Pneumococcal Conjugate Vaccine in adults in Liguria Region, Italy: one year post-introduction preliminary results]

Abstract

Objective: To assess the impact of the immunization program with 13-valent Pneumococcal Conjugate Vaccine (PCV13) in adults, from October 2013 in Liguria, Italy, both in terms of effectiveness, and tolerability and safety.

Methods: First study: descriptive epidemiology of the clinical burden of lower respiratory tract infections (LRTI) and the role of risk factors or co-morbidity in adults >18 years of age. Second study: crossover evaluation of the effect of PCV13 introduction in adults aged ≥70 years, in terms of ED accesses for LRTI, obtained by a Syndrome Surveillance System (SSS) operating in Liguria from 2007. Third study: evaluation of safety and tolerability profile of PCV13 in terms of local and systemic solicited and unsolicited adverse events.

Results: During pre-PCV period, annual cumulative incidence of ED accesses for LRTI was equal to 7/1000 and 2% in ≥65 and ≥85 year adults, respectively. In ≥65 years adults, more than 70% of identified subjects has at least one risk condition. A significant reduction in the incidence of ED accesses for LRTI in the vaccinated population, compared to non-vaccinated subjects, has already been observed: the preventive fraction, adjusted for age and seasonality, was estimated to be nearly 20%. PCV13 had a good safety and tolerability profile: rates of local (32%) and systemic (22%) solicited reactions resulted generally lower than those registered in clinical trials previously performed in the elderly.

Conclusions: Preliminary PCV13 assessments regarding safety and tolerability profile, together with the initial effects of the immunization program in terms of reduction of ED accesses for LRTI, confirmed the effectiveness of current Liguria Region recommendations for the prevention of pneumococcal disease in adult population.