Li Jing, Li Yifan, Qin Chuanyu, He Yu, Lu Haidong, Xie Yewei, Ong Jason J, Lu Yajiao, Yang Ying, Yang Fan, Du Heng, Gong Wenfeng, Zou Fei, Larson Heidi J, Jit Mark, Lin Leesa, Smith Jennifer S, Geng Elvin H, Xu Dong, Tang Weiming, Tang Shenglan, Tucker Joseph D, Wu Dan
West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China.
National Vaccine Innovation Platform & State Key Laboratory of Reproductive Medicine and Offspring Health & Department of Social Medicine and Health Education, School of Public Health, Nanjing Medical University, Nanjing, China.
PLoS Med. 2025 Jul 31;22(7):e1004535. doi: 10.1371/journal.pmed.1004535. eCollection 2025 Jul.
Catch-up human papillomavirus (HPV) vaccination is challenging in many low- and middle-income countries (LMICs). Pay-it-forward offers an individual a subsidized vaccine, then an opportunity to donate to help others access vaccinations. Our randomized control trial assessed the effectiveness of pay-it-forward in improving HPV vaccination among girls aged 15-18 years in China.
This study was conducted from July 6, 2022, to June 9, 2023, in four community health centers (CHCs) in Chengdu, western China. Eligible participants were unvaccinated girls living in the service areas of CHCs. Participants were initially recruited via telephone and, after providing verbal consent, attended in-person visit where they were randomly assigned using the sealed envelope method to either the pay-it-forward arm (received a community subsidy of 47.7 USD covering the first vaccine and an opportunity to support others) or control arm (self-paid vaccination at the market price). Participants were unblinded only after the envelope was opened, while the CHC staff coordinators, physicians prescribing the vaccine, outcome assessors, and data analysts were blinded to the intervention allocation. The primary outcome was the first-dose HPV vaccination rate, verified against clinical records. Data were analyzed using the intention-to-treat approach. We identified 662 participants per phone invitation. A total of 321 participants showed up in the health centers and randomly assigned to the pay-it-forward arm (n = 161) or control arm (n = 160). Most caregivers were female (80.1%, 257/321). In the pay-it-forward arm, 55 of 161 (34.2%) girls received the HPV vaccine, compared with 28 of 160 (17.5%) girls in the control arm (adjusted proportion difference = 17.9%, (95% CI [8.7%, 27.0%]; P < 0.001). Among 55 girls in the pay-it-forward arm who received the vaccination, 37 (67.3%) wrote a postcard message, and 39 (70.9%) of their caregivers donated to support future girls. The financial cost per person vaccinated was $294 in the control arm and $230 in the pay-it-forward arm. The trial had several limitations, including a 54% clinic attendance rate (360 of 662 consented participants attended) and its conduct in a single western province of China.
The pro-social pay-it-forward strategy was effective to increase catch-up HPV vaccination among teenage girls. This approach also enhanced vaccine confidence among participants. Pay-it-forward demonstrates promise as an effective intervention to improve vaccine uptake through community engagement.
Chinese clinical trial registry ChiCTR2200055542 (https://www.chictr.org.cn/hvshowproject.html?id=183292&v=1.3).
在许多低收入和中等收入国家（LMICs），补种人乳头瘤病毒（HPV）疫苗具有挑战性。“传递爱心”计划为个人提供补贴疫苗，然后提供一个捐赠机会，以帮助其他人获得疫苗接种。我们的随机对照试验评估了“传递爱心”计划在中国15至18岁女孩中提高HPV疫苗接种率的有效性。
本研究于2022年7月6日至2023年6月9日在中国西部成都的四个社区卫生中心（CHC）进行。符合条件的参与者是居住在社区卫生中心服务区域内未接种疫苗的女孩。参与者最初通过电话招募，在提供口头同意后，参加现场访问，在那里他们使用密封信封法随机分配到“传递爱心”组（获得47.7美元的社区补贴，涵盖第一剂疫苗，并获得支持他人的机会）或对照组（按市场价格自费接种疫苗）。只有在信封打开后参与者才不再被盲法，而社区卫生中心的工作人员协调员、开疫苗处方的医生、结果评估人员和数据分析人员对干预分配情况不知情。主要结果是首剂HPV疫苗接种率，通过临床记录进行核实。数据采用意向性分析方法进行分析。我们每发出一次电话邀请确定662名参与者。共有321名参与者出现在卫生中心，并随机分配到“传递爱心”组（n = 161）或对照组（n = 160）。大多数照顾者为女性（80.1%，257/321）。在“传递爱心”组中，161名女孩中有55名（34.2%）接种了HPV疫苗，而对照组160名女孩中有28名（17.5%）接种了疫苗（调整后的比例差异 = 17.9%，（95% CI [8.7%，27.0%]；P < 0.001）。在“传递爱心”组中接种疫苗的55名女孩中，37名（67.3%）写了明信片留言，她们的39名（70.9%）照顾者进行了捐赠，以支持未来的女孩。对照组中每人接种疫苗的财务成本为294美元，“传递爱心”组为230美元。该试验有几个局限性，包括诊所就诊率为54%（662名同意参与的参与者中有360名就诊）以及试验在中国西部的一个省份进行。
亲社会的“传递爱心”策略有效地提高了青少年女孩的HPV补种疫苗接种率。这种方法还增强了参与者对疫苗的信心。“传递爱心”计划作为一种通过社区参与提高疫苗接种率的有效干预措施显示出前景。
中国临床试验注册中心ChiCTR2200055542（https://www.chictr.org.cn/hvshowproject.html?id=183292&v=1.3）。
