Potential cost-effectiveness of the nonavalent human papillomavirus (HPV) vaccine

Randomized clinical trials are currently examining the efficacy of a nonavalent human papillomavirus (HPV) vaccine, including HPV-types 6/11/16/18/31/33/45/52/58. Evidence on the cost-effectiveness of the nonavalent is required for timely policy-decisions. We compared the potential cost-effectiveness of the nonavalent and quadrivalent HPV vaccines. We used a multitype individual-based transmission-dynamic model of HPV infection and diseases, 70-year time-horizon, 3% discount rate and healthcare payer perspective. We calibrated the model to Canadian sexual behavior and epidemiologic data, and estimated Quality-Adjusted Life-Years (QALYs) lost and costs ($CAN 2010) from the literature. Under base-case assumptions (vaccinating 10-year-old girls, 80% coverage, 95$/dose, vaccine-type efficacy = 95%, cross-protection for the quadrivalent vaccine, duration of vaccine-type protection (cross-protection) = 20 (10) years), using the quadrivalent and nonavalent vaccines is estimated to cost $15,528 [12,056; 19,140] and $12,203 [9,331; 17,292] per QALY-gained, respectively. At equal price, the nonavalent vaccine is more cost-effective than the quadrivalent vaccine, even when assuming both shorter duration of protection (nonavalent = 20 years vs. quadrivalent = lifelong) and lower vaccine-type efficacy (nonavalent = 85% vs. quadrivalent = 95%). However, the additional cost per dose of the nonavalent vaccine should not exceed $11 to remain more cost-effective than the quadrivalent vaccine, and $24 to represent a cost-effective alternative to the quadrivalent vaccine (using a $40,000/QALY-gained threshold). The nonavalent vaccine can be a cost-effective alternative to the quadrivalent vaccine, even in scenarios where nonavalent vaccine efficacy is 85%. However, because most cervical cancers are caused by HPV-16/18, it is unlikely that the nonavalent would be used if its efficacy against these types is lower than current HPV vaccines.