Many people are reluctant to get vaccinations, often owing to a fear of needles or misinformation about the jabs.Credit: Genaro Molina/Los Angeles Times/Getty

许多人不愿意接种疫苗，通常是因为害怕针头或关于刺针的错误信息。图片来源：Genaro Molina/洛杉矶时报/盖蒂

Vaccines save lives. The measles vaccine alone is estimated to have averted 23 million deaths between 2000 and 2018, according to the World Health Organization (WHO). Data from a subset of countries where girls are vaccinated against the human papillomavirus show that precancerous cervical lesions in girls aged 15–19 plummeted by 51% within a few years of vaccine rollout1.

。据世界卫生组织（WHO）估计，仅麻疹疫苗就可以在2000年至2018年间避免2300万人死亡。来自女孩接种人乳头瘤病毒疫苗的一部分国家的数据显示，疫苗接种后几年内，15-19岁女孩的宫颈癌前病变下降了51%。

Globally, vaccination rates are increasing for many diseases. However, in 2022 (the latest year for which data are available), there were still 14.3 million ‘zero-dose’ children — those who had not received any routine immunizations.A lack of access to vaccines and the high costs of producing and purchasing them are among the main reasons for low uptake, especially in low- and middle-income countries.

在全球范围内，许多疾病的疫苗接种率正在上升。然而，在2022年（有数据的最近一年），仍然有1430万“零剂量”儿童-那些没有接受任何常规免疫接种的儿童。缺乏获得疫苗的机会以及生产和购买疫苗的高昂成本是接种率低的主要原因之一，尤其是在中低收入国家。

In high-income countries, vaccine hesitancy is a significant factor2. This is fuelled, in part, by misinformation, which is a problem worldwide3.Countries already have a range of strategies for boosting uptake. All should study the work of researchers who have been evaluating the effectiveness of different interventions.

在高收入国家，疫苗犹豫是一个重要因素2。这在一定程度上是由于错误信息造成的，这是世界范围内的一个问题3。各国已经有一系列提高吸收率的策略。所有人都应该研究研究人员的工作，他们一直在评估不同干预措施的有效性。

The burgeoning science of vaccine-uptake effectiveness is throwing up some unexpected results that could help public-health authorities to sharpen their policies — and save more lives..

新兴的疫苗接种有效性科学正在产生一些意想不到的结果，这些结果可能有助于公共卫生部门改进政策，挽救更多的生命。。

Bird flu in US cows: where will it end?

美国奶牛的禽流感：将在哪里结束？

Take the United States. By October 2022, almost two years after the first COVID-19 vaccines were rolled out, 80% of people in the country aged six months and older had received at least one dose. However, only 33% had received a follow-up booster, which offers the highest possible level of protection against the SARS-CoV-2 virus.The low booster numbers drove some states to investigate how uptake might be increased.

以美国为例。到2022年10月，即第一批新型冠状病毒疫苗推出近两年后，该国80%的6个月及以上的人至少服用了一剂。然而，只有33%的人接受了后续加强治疗，这为SARS-CoV-2病毒提供了最高水平的保护。。

Researchers and health authorities have highlighted ‘last-mile vaccination delivery’ as a major barrier to uptake. In 2021, the White House came up with the idea of encouraging people to get their boosters by offering them free transport to clinics through the ride-hailing companies Lyft and Uber. But a study published in Nature last month4 shows that this might have done little to increase booster uptake.Economist Katherine Milkman at the University of Pennsylvania (UPenn) in Philadelphia and her colleagues compared the offer of a free ride with other interventions in a study involving 3.66 million patients of CVS Pharmacy, a retailer that provides vaccination services.

研究人员和卫生当局强调，“最后一公里疫苗接种”是吸收的主要障碍。2021年，白宫提出了一个想法，通过叫车公司Lyft和优步（Uber）为人们提供免费前往诊所的交通工具，鼓励人们购买助推器。但上个月发表在《自然》杂志上的一项研究表明，这可能对增加助推器的吸收几乎没有作用。费城宾夕法尼亚大学（UPenn）经济学家凯瑟琳·米克曼（KatherineMilkman）和她的同事在一项涉及366万名CVS Pharmacy患者的研究中，将免费乘车与其他干预措施进行了比较，CVS Pharmacy是一家提供疫苗接种服务的零售商。

The patients, who had all previously been vaccinated against COVID-19, were split into eight groups. One group received a text message offering free transport to the pharmacy; the other seven were sent different text-message reminders to get their boosters..

这些患者之前都接种过新型冠状病毒肺炎疫苗，分为八组。其中一组收到一条短信，免费送药房；另外七个人收到了不同的短信提醒，以获得他们的支持。。

A global pandemic treaty is in sight: don’t scupper it

全球大流行条约在望：不要破坏它

People offered free transport were not more likely to get vaccinated than were those who received the other kinds of text message. Messages that had a more positive effect included one proposing an appointment for a day of the week and time of day similar to that of a patient’s previous vaccination, and one informing the recipient that infection rates were high in their county.“Our article really highlights the importance of testing policy,” says study co-author Sean Ellis, also at UPenn.

提供免费交通服务的人比那些收到其他类型短信的人更不可能接种疫苗。产生更积极影响的信息包括一条建议预约一周中的一天和一天中的时间，类似于患者之前接种疫苗的时间，以及一条通知接受者他们所在县的感染率很高。“我们的文章确实强调了测试政策的重要性，”同样在UPenn的研究合著者肖恩·埃利斯（SeanEllis）说。

“Whatever policy we’re putting into place, we should be robustly evaluating whether it actually works, so that if it does work, we can scale it up or continue to do it. And if it doesn’t, we can move on from it and try something else.” In other words, studies are needed to evaluate whether ‘common sense’ interventions actually work in practice.Researchers are also helping to evaluate the overall effectiveness of text messaging on vaccine uptake.

“无论我们实施什么政策，我们都应该强有力地评估它是否真的有效，这样如果它有效，我们就可以扩大规模或继续这样做。如果不起作用，我们可以从它开始，尝试其他东西。”换句话说，需要进行研究来评估“常识”干预措施在实践中是否有效。研究人员还帮助评估短信对疫苗摄取的总体有效性。

In a study published in May, Hongyu Guan at Shaanxi Normal University in Xi’an, China, and colleagues used the 2021 Chinese General Social Survey, a periodic national survey of households, to examine the actions of 7,281 people. They found that those who received notifications from their local government or community residents’ committees advising them to get vaccinated were twice as likely to get a COVID-19 vaccine than were those who did not5..

在5月份发表的一项研究中，中国西安陕西师范大学的关宏宇及其同事使用了2021年中国社会普查，这是一项定期的全国家庭调查，调查了7281人的行为。他们发现，那些收到当地政府或社区居民委员会建议他们接种疫苗的通知的人，接种新型冠状病毒疫苗的可能性是没有接种的人的两倍。。

Half a million children die of malaria every year – finally we can change that

每年有50万儿童死于疟疾——最终我们可以改变这种情况

The same study showed that the practice also increased influenza vaccine uptake, albeit from a much lower base. Uptake was more than 40% higher for those notified compared with those who did not receive a text message. This finding builds on the work of earlier studies6. However, researchers are less certain whether these approaches are effective for people who are reluctant to be vaccinated7.In low-income countries, research shows that uptake increases when vaccines are taken into communities.

同一项研究表明，这种做法也增加了流感疫苗的摄取量，尽管基础要低得多。与没有收到短信的人相比，收到通知的人的接受率高出40%以上。这一发现建立在早期研究的基础上6。然而，研究人员不太确定这些方法是否对不愿意接种疫苗的人有效7。在低收入国家，研究表明，当疫苗进入社区时，摄取量会增加。

In Sierra Leone, for example, the average person lives 3.5 hours away from a vaccination centre and the cost to travel there exceeds their weekly wage. A study published in March8 found that significantly more people in the country received their COVID-19 vaccines when mobile teams of vaccinators were deployed to 150 rural communities.Increasing vaccine access and accessibility saves lives, but is only part of the equation.

例如，在塞拉利昂，人们平均离疫苗接种中心3.5小时，前往那里的费用超过了他们的周工资。3月8日发表的一项研究发现，当向150个农村社区部署流动疫苗接种小组时，该国接受新型冠状病毒疫苗的人数明显增加。增加疫苗的获取和可及性可以挽救生命，但这只是方程式的一部分。

Other interventions are needed to maximize uptake, and these must undergo rigorous testing in different regions and contexts to help health authorities to determine what works. The obvious answer is not always the right one, and the vagaries of human behaviour can thwart seemingly logical solutions..

需要其他干预措施来最大程度地提高吸收率，这些干预措施必须在不同的地区和背景下进行严格的测试，以帮助卫生当局确定哪些措施有效。显而易见的答案并不总是正确的，人类行为的变幻莫测可能会阻碍看似合乎逻辑的解决方案。。