Spotlight on Human Papillomavirus Vaccination Coverage: Is Nigeria Making Any Progress?

Abstract

The tragedy of losing one woman every 2 minutes to cervical cancer is regrettable in the face of advancements in cervical cancer prevention and treatment. 1 Despite being a largely preventable disease through human papillomavirus (HPV) vaccination and screening, the burden of cervical cancer is increasing each year with a concomitant widening of global health inequities. 1,2 In terms of global cancer incidence and mortality, cervical cancer ranks fourth with an estimated 604,000 new patients and 342,000 deaths in 2020. 2 It is alarming to note that about 90% of the global cervical cancer incidence and mortality occur in low-and middle-income countries (LMICs), with women of low socioeconomic status bearing the greatest burden. 2,3 Such disparities in cervical cancer burden demonstrate huge socioeconomic gaps between countries and inequitable implementation of cervical cancer prevention and control measures including HPV vaccination and organized screening programmes. 4 Hence, it becomes morally imperative to address stark inequities in global cervical cancer burden and prevention efforts especially in LMICs. In Nigeria, an estimated incidence of 12,100 patients and 8,000 deaths in 2020 puts cervical cancer as the second leading cause of female cancer morbidity and mortality behind breast cancer. 2 Even more disturbing is that an estimated 60.9 million Nigerian women age 15 years and older will be at greater risk of developing cervical cancer in the absence of cost-effective strategies to scale up prevention and early detection. 5 The 90-70-90 targets to be met by 2030 as contained in the global strategy to accelerate the elimination of cervical cancer as a public health problem raises optimism among LMICs including Nigeria despite skeptics describing it as overly ambitious and not realistic. Specifically, the 90-70-90 targets set out to see that 90% of girls are fully vaccinated with HPV vaccine by age 15 years, 70% of women are screened with a high-performance test at 35 years and again at 45 years and that 90% of women identified with cervical disease receive treatment. 1 Vaccination of adolescent girls with HPV vaccines before the onset of sexual activity is the most effective long-term intervention for reducing the risk of developing cervical cancer. Knowledge of the causal relationship between HPV infection and cervical cancer has stimulated advances in the development, licensing, and usage of HPV vaccines. 6,7 Evidence from population studies including post-vaccination follow-up has shown HPV vaccines to be highly immunogenic, safe, and effective in preventing HPV infection, cervical lesions, anogenital warts, and other HPV-related diseases. 8 Currently, six HPV vaccines are licensed for use by the WHO-bivalent HPV vaccines (cervarix, cecolin, and walrinvax), quadrivalent HPV vaccines (gardasil and cervarax), and nonavalent HPV vaccine (gardasil9). 7 Providing protection against high-risk (oncogenic) HPV types 16 and 18 that cause the majority of precancers, cervical cancers, and other HPV-related cancers is a unique characteristic across the licensed vaccines. WHO's guidelines recommend that adolescent girls between 9 and 14 years receive two doses of vaccine to be fully immunized with at least a 6-month interval between doses, with exceptions for special populations including immunocompromized individuals and those age 15 years or older, for whom three doses are recommended. 7 In 2022, following evidence that a single dose of HPV vaccine provided similar protection against HPV infection as seen in multidose regimen, 9 the WHO updated its HPV vaccination recommendations to include a single-dose schedule (also referred to as alternative or off-label single-dose schedule) for individuals age 9-20 years. 7 The single-dose schedule update is timely and can help countries such as Nigeria to introduce the HPV vaccine, improve coverage, and cut associated costs.