Review of the initial post-marketing safety surveillance for the recombinant zoster vaccine

The adjuvanted recombinant zoster vaccine (RZV) received its first marketing authorization in October 2017, for prevention of herpes zoster in individuals aged ≥50 years. We summarized safety information, following RZV administration, received by GSK via spontaneous adverse event (AE) reports submitted by healthcare providers, vaccine recipients and other reporters. Observed-to-expected (O/E) analyses were performed for selected outcomes: reports of death, Guillain–Barré syndrome and Bell's palsy. Standard case definitions were used to assess individual case reports. Data mining, using proportional reporting ratio and time-to-onset signal detection methods, was employed to identify RZV-AE pairs with disproportionate reporting or unexpected time-to-onset distribution. Between October 13, 2017 and February 10, 2019, an estimated 9.3 million doses were distributed and GSK received 15,638 spontaneous AE reports involving RZV. Most reports were classified as non-serious (95.3%) and originated from the United States (81.7%), where the majority of doses were distributed. Among reports with age or sex reported, individuals were mainly 50–69-year-olds (62.1%) and female (66.7%). Of all reports, 3,579 (22.9%) described vaccination errors, of which 82.7% were without associated symptoms. Of all vaccination error reports, most described errors of vaccine preparation and reconstitution (29.7%), inappropriate schedule or incomplete course of administration (26.7%), incorrect route of administration (16.4%), and storage errors (12.9%). The most commonly reported symptoms were consistent with the known RZV reactogenicity profile observed in clinical trials, including injection site reactions, pyrexia, chills, fatigue, headache. O/E analyses for selected outcomes and data mining analyses for all reported AEs did not identify any unexpected patterns. Review of the initial data from the post-marketing safety surveillance showed that the safety profile of RZV is consistent with that previously observed in pre-licensure clinical trials. Other studies are ongoing and planned, to continue generating real-world safety data and further characterize RZV.