HPV vaccines have excellent safety profiles internationally. There have been no safety signals raised since the vaccines were licensed, and a number of large investigations have been carried out to assess specific outcomes, particularly autoimmune conditions.69, 70, 71, 72, 73 Post-marketing surveillance systems globally continue to monitor the safety of HPV vaccination programmes.74, 75, 76 The WHO’s Global Advisory Committee on Vaccine Safety has systematically reviewed HPV vaccine safety and has not found any safety issue that would alter its recommendations for use.77 The main challenge with HPV vaccine is communicating its excellent safety profile.78 (See also section 3.3.1.)
Safety has been evaluated in approximately 15,000 subjects in the HPV9 clinical development programme.65 The vaccine is well-tolerated, and most adverse events were injection site-related pain, swelling, and erythema that were mild to moderate in intensity. The safety profiles were similar in HPV4 and HPV9 vaccinees. Female HPV9 recipients had more injection site adverse events than female HPV4 recipients, including swelling (40.3 percent compared to 29.1 percent in HPV4 recipients) and erythema (34 percent compared to 25.8 percent in HPV4 recipients). Injection site adverse events were similar in males following either vaccine. Male recipients had fewer injection site adverse events. Rates of injection-site swelling and erythema both increased following each successive dose of HPV9.
In summary, HPV9 is well-tolerated in all age groups, although it is slightly more reactogenic than HPV4.45, 47, 65 The most common adverse events are pain, swelling, erythema, pruritus, headache and pyrexia.