Journal of Vaccine Research 2024, Vol.14, No.6, 307-315 http://medscipublisher.com/index.php/jvr 311 5.3 Feasibility of promoting different vaccines in various economic environments The choice of which HPV vaccine to promote often depends on a country’s economic situation and healthcare system. In wealthier countries, the nonavalent vaccine may be worth its higher price because it offers broader protection and can help lower the number of HPV-related diseases. For example, a study in Singapore found that the nonavalent vaccine was cost-effective compared to the bivalent vaccine. However, it also noted that the price would need to drop significantly before it could be added to the national vaccination program (Markowitz et al., 2018). In lower-income countries, cost and access are bigger challenges. Giving multiple doses can also be harder to manage. In these settings, using the bivalent or quadrivalent vaccines with a two-dose schedule may be more realistic and affordable. For instance, a study in Taiwan showed that the bivalent vaccine was more cost-effective than the quadrivalent one, mainly because it provides extra cross-protection against cancer-causing HPV types, even though the quadrivalent vaccine also protects against genital warts. 6 Global Strategies and Effects of HPV Vaccine Implementation 6.1 Analysis of national policies promoting bivalent, quadrivalent, and nonavalent vaccines HPV vaccination policies differ widely between countries. These differences are shaped by each country’s healthcare system, financial resources, and public health goals. For example, Norway has taken strong steps over the past decade to fight cervical cancer. In 2009, it introduced routine HPV vaccination for 12-year-old girls using the quadrivalent vaccine. Later, it offered a temporary catch-up program with the bivalent vaccine. In 2021, Norway switched to the nonavalent vaccine. Together, these changes helped speed up the timeline for cervical cancer elimination by over 17 years and prevented thousands of cases (Mariz et al., 2021). In the United States, the nonavalent vaccine has shown better health benefits and cost-effectiveness than the bivalent or quadrivalent vaccines. But vaccine coverage still varies a lot between states. To get the most benefit, national efforts need to focus on improving coverage, especially in states with the lowest vaccination rates. Targeting those areas can help increase herd immunity, lower cervical cancer rates, and reduce healthcare costs (Portnoy et al., 2021). 6.2 Regional differences in vaccination coverage and vaccine protection effectiveness HPV vaccine coverage and effectiveness can differ a lot between regions. In Canada, a model-based study predicted that giving 12-year-old girls the bivalent or quadrivalent vaccine would greatly reduce cases of genital warts, cervical precancer (CIN), and cervical cancer over 70 years. Switching to the nonavalent vaccine could lower these numbers even more, showing how vaccine choice plays a key role in public health planning (Garland et al., 2016). In India, a study looked at how well a single dose of the quadrivalent HPV vaccine worked. The results showed that one dose gave strong and lasting protection against HPV types 16 and 18—similar to getting two or three doses. This is especially important for low-income countries, where access to cervical cancer screening and care is often limited. The findings suggest that a single-dose approach could help boost vaccination rates and lower cervical cancer risk in these areas (Durham et al., 2016). 6.3 Real-world impact of hpv vaccines on cervical cancer and related disease incidence HPV vaccines have had a big impact in the real world, especially in lowering rates of cervical cancer and related diseases. A review of data from ten years of using the quadrivalent vaccine showed large drops in infections from HPV types 6, 11, 16, and 18. It also showed fewer cases of genital warts and cervical lesions (Wang et al., 2021). Another review stressed the importance of using good study designs and strong data to track vaccine outcomes. It also highlighted the need for global monitoring to help reach the WHO’s goal of eliminating cervical cancer. 7 Future Research Directions and Optimization Strategies for HPV Vaccines 7.1 Progress in the development of more efficient and broad-spectrum HPV vaccines Recent progress in HPV vaccine research has focused on making vaccines that are more effective and offer wider
RkJQdWJsaXNoZXIy MjQ4ODYzNQ==