After the change from a three-dose (0, 1 and 6 months) to a two-dose schedule (0 and 6 months) for HPV vaccination in the Netherlands in 2014, tolerability among girls was monitored and compared with the tolerability after the three-dose schedule measured in 2010.
Local and systemic adverse events (AEs) occurring within 7 days following each dose were obtained by online questionnaires. We also obtained online questionnaires on symptoms occurring in the week before vaccination.
Following the two-dose schedule, girls reported local reactions in 86.1% (1st dose) and 82.0% (2nd dose) compared to 88.5% (1st dose), 79.5% (2nd dose) and 79.2% (3rd dose) in girls receiving three doses. For systemic AEs reported frequencies were 73.0% (1st dose) and 71.6% (2nd dose) compared with 85.9% (1st dose), 74.5% (2nd dose) and 75.8% (3rd dose). Overall, the two-dose schedule resulted in 32.0% less local reactions and 38.8% less systemic AEs than the three-dose schedule. The most reported local reactions were pain and reduced use of the arm. With respect to the systemic AEs, myalgia, fatigue and headache were the most reported. However, symptoms such as fatigue, headache and cold, were reported similar or even more in the week before compared to the week after vaccination in girls who had received the two-dose schedule. This data was in line with symptoms reported by girls before the third dose of the three-dose schedule.
Local and systemic AEs were frequently reported within 7 days following HPV vaccination in a two-dose schedule. The tolerability of the first dose was more favourable compared with the first dose of the former three-dose schedule. For the dose at six months, the tolerability was comparable for both schedules. In conclusion, the change to a two-dose schedule resulted in considerable fewer AEs, which potentially improves acceptance of vaccination.