Safety and tolerability of 13-valent pneumococcal conjugate vaccine in the elderly: An observational study in Liguria Region, Italy

Background: In September 2011 the European Medical Agency authorized the use of 13-valent pneumococcal conjugate vaccine (PCV13) in adults aged \ue2\u89\ua550 years. The same occurred in the US in December 2011 when the Food and Drug Administration approved the use of PCV13 in the same target age-group with indication for the prevention of invasive pneumococcal diseases and community acquired pneumonia sustained by the serotypes contained in the vaccine. The Liguria Region, in Italy, implemented in 2013 an active and free of charge immunization strategy with PCV13 among adults affected by specific risk conditions and the elderly aged \ue2\u89\ua570 years. Methods: An observational study was performed in order to assess the safety and tolerability of PCV13 among elderly dwelling in the metropolitan area of Genoa, the capital city of Liguria Region. Eligible subjects, who received PCV13 following the public health immunization campaign at the Local Health Unit 3 of Genoa, provided a written informed consent to take part in the study. Eight-hundred-seventy-one subjects were enrolled between October 2013 and May 2014: all were monitored by qualified healthcare personnel for at least 30 min after vaccination at the outpatient clinics, in order to assess any possible sudden reaction. The occurrence of a series of local and systemic solicited reactions and of any unsolicited Adverse Events (AEs) was monitored using a self-administered clinical diary and by regular phone contacts up to 14 and 21 d following immunization, respectively. Moreover, a 6-months follow-up following vaccination was planned in order to monitor Severe Adverse Events (SAEs). Results: No sudden reaction occurred in vaccinees at the outpatient clinics. Pain (27.4%) was the most frequent reaction reported by subjects at the injection site, while new muscle pain (13.6%), fatigue (10.7%), and headache (9.9%) resulted the most common systemic reactions. Rates of the main reactions reported in this on-field study resulted generally lower than those registered in clinical trials performed in the elderly. The incidence of fever (2.2%) following vaccination was low at values superimposable to that reported in previous studies. Conclusion: This observational study showed a good safety and tolerability of PCV13 among the elderly in routine clinical practice further confirming the evidence coming from clinical trials in the same age-group