The 9-valent HPV vaccine (9vHPV) was licensed in the United States in 2014 and recommended for vaccination of females and males in 2015. CDC continuously monitors vaccine safety during the post-licensure period using several systems, including the Vaccine Adverse Event Reporting System (VAERS) and the Vaccine Safety Datalink (VSD). VAERS is a national spontaneous reporting system co-managed by CDC and FDA. VSD is an active surveillance system that is a collaboration between CDC and 9 US integrated healthcare delivery systems. We describe 9vHPV safety data from VAERS, and compare with data for quadrivalent HPV vaccine (4vHPV). We also describe VSD monitoring for 9vHPV.
We searched VAERS for US reports of adverse events (AE) following 9vHPV from December 2014-December 2016. We conducted descriptive analyses of commonly reported AEs, estimated AE reporting rates, and performed clinical review of selected pre-specified conditions. In VSD, we conducted weekly near-real time sequential monitoring of 11 pre-specified health conditions (Guillain-Barré syndrome, chronic inflammatory demyelinating polyneuropathy, anaphylaxis, stroke, venous thromboembolism, appendicitis, pancreatitis, seizures, syncope, allergic reaction, injection site reactions) among males and females aged 9-26 years using sequential analyses to detect associations.
From December 2014-December 2016, approximately 19 million 9vHPV doses were distributed in the United States. VAERS received 4,348 reports following 9vHPV; 29% in females, 22% in males, 49% sex missing/unknown. Overall, 98% of reports were non-serious; dizziness (8%) and syncope (7%) were most commonly reported in males and females. Headache (42%), nausea (35%), and dizziness (28%) were the most common signs and symptoms among serious reports. In comparison for 4vHPV, between June 2006-December 2015, the majority of reports were also non-serious (93%) with similar adverse events; syncope (12%) and dizziness (12%) were the most common signs and symptoms. Headache (29%), nausea (22%), and fatigue (22%) were the most common symptoms among serious reports. To date in VSD monitoring, 671,361 9vHPV doses have been administered; syncope and local injection site reactions are the only pre-specified conditions to signal (i.e. higher than expected numbers of adverse outcomes), both of which are known and expected AEs.
The 9vHPV safety profile to date is consistent with data from pre-licensure trials and comparable with post-licensure surveillance and epidemiologic studies for 4vHPV. Safety monitoring and evaluation of 9vHPV will continue to ensure rapid availability of information for immunization programs and the public.