Optimal allocation strategies for HPV vaccination introduction and expansion in China accommodated to different supply and dose schedule scenarios: A modelling study

Parental willingness of HPV vaccination in Mainland China: A meta-analysis

This meta-analysis aimed to systematically review and analyze parental awareness of human papillomavirus (HPV) and its vaccine, as well as parental willingness of the HPV vaccine in China. The literature search selected studies that met the following criteria: study published between 2009 and 2023, study design involving parents with at least one child aged ≤ 18 years, sample sizes exceeding 300, availability of data on parental willingness of the HPV vaccine or sufficient information to calculate effect sizes, and studies published in either English or Chinese. Studies that did not meet one of the above points were excluded. From an initial pool of 660 papers, 33 studies were included, encompassing a total sample size of 92,802. The analysis revealed that the pooled awareness rates of HPV and the HPV vaccine among Chinese parents were 45.0% (95% CI: 36.1-54.0%) and 41.4% (95%CI: 30.7-52.5%), respectively. The overall parental willingness for vaccinating children against HPV was 61.0% (95% CI: 53.5-68.3%). Both parental awareness and willingness of the HPV vaccine in China were found to remain low when compared to other countries.

Viral vector- and virus-like particle-based vaccines against infectious diseases: A minireview

To overcome the limitations of conventional vaccines, new platforms for vaccine design have emerged such as those based on viral vectors and virus-like particles (VLPs). Viral vector vaccines are highly efficient and the onset of protection is quick. Many recombinant vaccine candidates for humans are based on viruses belonging to different families such as Adenoviridae, Retroviridae, Paramyxoviridae, Rhabdoviridae, and Parvoviridae. Also, the first viral vector vaccine licensed for human vaccination was the Japanese encephalitis virus vaccine. Since then, several viral vectors have been approved for vaccination against the viruses of Lassa fever, Ebola, hepatitis B, hepatitis E, SARS-CoV-2, and malaria. VLPs are nanoparticles that mimic viral particles formed from the self-assembly of structural proteins and VLP-based vaccines against hepatitis B and E viruses, human papillomavirus, and malaria have been commercialized. As evidenced by the accelerated production of vaccines against COVID-19, these new approaches are important tools for vaccinology and for generating rapid responses against pathogens and emerging pandemic threats.

Inequities in human papillomavirus vaccination among children aged 9-14 years old under constrained vaccine supply in China

BACKGROUND

Inequities in access to human papillomavirus (HPV) vaccine are becoming a growing critical issue globally. Few studies investigate the factors determining HPV vaccine uptake disparities when vaccine supply is constrained, especially in low- and middle-income countries. The aim of this study was to investigate inequities of HPV vaccination and related factors under the constrained vaccine supply in China.

METHODS

A cross-sectional survey was conducted in a developed eastern coastal province and a developing western one in China between November and December 2022. Employing multistage stratified cluster random sampling, the study collected data from parents of children aged 9-14. Mixed-effects logistic regression models with school units as random effects were used for analysis.

RESULTS

From 4,127 eligible parents (as vaccine decision makers for girls), 1,346 (32.6%) intended to vaccinate their daughters against HPV, of which 836 (62.1%) attempted to schedule a vaccination appointment. Only 16.4% succeeded in booking an appointment. More than half of the intended parents expected the imported 9-valent HPV vaccine. There were significant disparities in HPV vaccine awareness, intention, and vaccination behavior across educational, income, geographic, ethnic, gender, and health literacy levels. Vaccine awareness and intentions were higher among parents with higher socioeconomic status; however, girls from lower socioeconomic families were more likely to receive the HPV vaccine and had a higher domestically produced vaccination rate. Significant disparities exist in vaccination intentions and actual vaccination behaviors, primarily due to large supply constraints of the HPV vaccine.

CONCLUSIONS

Sustained health education campaigns are needed to raise awareness of the HPV vaccine, improve health literacy, and decrease over-preference for the 9-valent HPV vaccine. A mother's HPV vaccination behavior was positively associated with increased intention and actual vaccination behavior for her daughter. This study advocates for complementary cervical cancer prevention programs targeting both mothers and daughters.

Modeling the Health Impact and Cost-Effectiveness of a Combined Schoolgirl HPV Vaccination and Cervical Cancer Screening Program in Guangdong Province, China

Low human papillomavirus (HPV) vaccine uptake is a key barrier to cervical cancer elimination. We aimed to evaluate the health impact and cost-effectiveness of introducing different HPV vaccines into immunization programs and scaling up the screening program in Guangdong. We used a dynamic compartmental model to estimate the impact of intervention strategies during 2023-2100. We implemented the incremental cost-effectiveness ratio (ICER) in costs per averted disability-adjusted life year (DALY) as an indicator to assess the effectiveness of the intervention. We used an age-standardized incidence of 4 cases per 100,000 women as the threshold for the elimination of cervical cancer. Compared with the status quo, scaling up cervical cancer screening coverage alone would prevent 215,000 (95% CI: 205,000 to 227,000) cervical cancer cases and 49,000 (95% CI: 48,000 to 52,000) deaths during 2023-2100. If the coverage of vaccination reached 90%, domestic two-dose 2vHPV vaccination would be more cost-effective than single-dose and two-dose 9vHPV vaccination. If Guangdong introduced domestic two-dose 2vHPV vaccination at 90% coverage for schoolgirls from 2023 and increased the screening coverage, cervical cancer would be eliminated by 2049 (95% CI 2047 to 2051). Introducing two doses of domestic 2vHPV vaccination for schoolgirls and expanding cervical cancer screening is estimated to be highly cost-effective to accelerate the elimination of cervical cancer in Guangdong.

The clinical effectiveness of one-dose vaccination with an HPV vaccine: A meta-analysis of 902,368 vaccinated women

BACKGROUND

The comprehensive effectiveness of the HPV vaccine has been widely acknowledged. However, challenges such as dosing adherence and limited budgets have led to delays in HPV vaccination implementation in many countries. A potential solution to these issues could lie in a one-dose vaccination with an HPV vaccine, as indicated by promising outcomes in multiple studies.

METHODS

In this systematic review and meta-analysis, we examine the comparative effectiveness of the one-dose vaccination with an HPV vaccine against two- and three-dose regimens. Our investigation focuses on clinical efficacy, encompassing the prevention of HPV16, HPV18, and hrHPV infections, HSIL or ASC-H incidence, and CIN2/3 incidence.

RESULTS

Our analysis suggests that a single-dose HPV vaccine may offer effectiveness on par with two- or three-dose schedules. This conclusion is drawn from its capacity to confer immunogenic protection for at least 8 years of follow-up, coupled with its ability to mitigate infections and pre-cancerous occurrences.

CONCLUSION

While our findings underscore the potential of the one-dose vaccination with an HPV vaccine, further research and prolonged study durations are necessary to establish robust evidence supporting this recommendation. As such, continued investigation will be critical for informing vaccination strategies.

Virus-like particles as powerful vaccination strategy against human viruses

Nowadays, viruses are not only seen as causative agents of viral infectious diseases but also as valuable research materials for various biomedical purposes, including recombinant protein production. When expressed in living or cell-free expression systems, viral structural proteins self-assemble into virus-like particles (VLPs). Mimicking the native form and size of viruses and lacking the genetic material, VLPs are safe and highly immunogenic and thus can be exploited to develop antiviral vaccines. Some vaccines based on VLPs against various infectious pathogens have already been licenced for human use and are available in the commercial market, the latest of which is a VLP-based vaccine to protect against the novel Coronavirus. Despite the success and popularity of VLP subunit vaccines, many more VLPs are still in different stages of design, production, and approval. There are still many challenges that require to be addressed in the future before this surface display system can be widely used as an effective vaccine strategy in combating infectious diseases. In this review, we highlight the use of structural viral proteins to produce VLPs, emphasising their intrinsic properties, structural classification, and main expression host systems. We also compiled the recent scientific literature about VLP-based vaccines to underline the recent advances in their application as a vaccine strategy for preventing and fighting virulent human pathogens. Finally, we presented the key challenges and possible solutions for VLP-based vaccine production.

Towards elimination of cervical cancer - human papillomavirus (HPV) vaccination and cervical cancer screening in Asian National Cancer Centers Alliance (ANCCA) member countries

About 95% of cervical cancers worldwide are caused by human papillomavirus (HPV). Cervical cancer is preventable and curable if it is detected and treated early. We reviewed the latest national cervical cancer indicators, and barriers to HPV vaccination and cervical cancer screening in 21 Asian National Cancer Centers Alliance (ANCCA) member countries. Half (n = 11, 52%) of the countries have introduced HPV vaccination for girls as part of their national vaccination programme, three countries reported coverage of over 90%. Most ANCCA member countries have cervical cancer screening programmes, only five countries reported screening uptake of over 50%. The barriers to HPV vaccination coverage and cervical cancer screening participation have been identified. Ensuring health service accessibility and affordability for women, addressing sociocultural barriers, and strengthening the healthcare system and continuum of care are essential to increase HPV vaccination and cervical cancer screening coverage.

Tackling barriers to scale up human papillomavirus vaccination in China: progress and the way forward

The human papillomavirus (HPV) vaccine is the first vaccine developed specifically targeting the prevention of cervical cancer. For more than 15 years, China has expedited a series of efforts on research and development of the domestically manufactured HPV vaccines, producing local population-based evidence, promoting free HPV vaccination from pilots, and launching action plans to tackle barriers in the scale-up of HPV vaccination. To further roll out the HPV vaccination program in China, several challenges should be addressed to support the steps forward. The availability of more locally manufactured HPV vaccines, pricing negotiation and local evidence supporting the efficacy of one-dose schedule would greatly alleviate the continued supply and financial constraints in China. Meanwhile, more attention should be paid to girls living in low-resource areas and males to ensure equal access to the HPV vaccination. Furthermore, linkage to secondary prevention and further real-world monitoring and evaluation are warranted to inform effective cervical cancer prevention strategies in the post-vaccine era.