轉發：怎樣對待反疫苗態度？

最近遇到一位幾年不見的朋友，聽信「周圍」的小道傳聞，不相信疫苗能防病，反相信接種會損害自身的「自然免疫力」。她還不相信各路媒體的報導和官方數據，真有些不知怎樣說服她回到科學。

今天看見國家醫學圖書館密蘇里州公共醫學雜誌的網站有一篇文章，Christopher A. Swingle醫生寫的。文章題目是How Do We Approach Anti-Vaccination Attitudes? 很多人引用，決定記下來。我只把作者寫的開頭摘要翻成中文，把對內容的評論放在括號內。

Abstract 我們作為醫生，普遍認為很多事情是理所當然的。你不需要醫療統計的背景就可以理解安全帶可以救命和減少汽車事故的傷害。你也不需要流行病學學位才知道吸煙會引起肺癌。你讀本科的時候，幾乎可以肯定是聽過擠奶工人Edward Jenner和天花疫苗的故事。Jonas Salk博士是20世紀真正的英雄，他研發的安全有效疫苗根除了美國的小兒麻痺症，最後一個小兒麻痺症案例發生在1979年。疫苗接種的好處顯然超過了風險，因此我們現在幾乎不知道還有麻疹，腮腺炎，風疹和白喉...呃，真的？

毫無疑問，我們的醫學培訓還學到其他東西，是教科書中所沒有的。從國家到個人，我們還知道人們的價值觀未必相同。國與國之間，在最糟的情況下，不同的價值觀會表現為外交爭端和戰爭。在醫師患者層面上，醫生試圖說服糖尿病患者，快餐解饞的價值沒有注意飲食營養與運動的價值大。我們感到自己花了好幾年功夫學習的醫學知識好像是第二本性，因此使用疫苗的邏輯應該對每個人都很明顯，但其實是未必的。

Anti-Vaccination Movement Is Long-Standing 反疫苗運動由來已久
Even in Edward Jenner’s time, there was an anti-vaccination movement. Sir William Osler醫生 got so fed up with the “anti-vaxxers” of 1910 that he dared them to expose themselves to smallpox and promised to personally pay for the resulting funeral expenses. He did not get any takers. Historically, anti-vaccination sentiment gains momentum once the worst infectious diseases were no longer visible to the public. Now that there is a whole schedule of vaccinations, many of the most dreaded childhood infectious diseases have lost visibility. From this place of comfort and safety made possible by widespread vaccination, we now have to contend with a resurgent anti-vaccination movement. (也許Osler醫生挑戰他們去大膽接觸傳染源，承諾賠償葬禮費用是有用的一招。)

Spend a few minutes on social media, or watch the feel-good daytime television shows ubiquitous in patients’ hospital rooms. Wouldn’t it be nice to have the same reach to millions that charismatic opportunists like Dr. Oz or Jenny McCarthy have? Could a few snarky pro-vaccination Facebook memes go viral and change minds our way for once? Until such time, physicians will have to leverage the physician-patient relationship in a smart and persuasive way.

To know how to intelligently respond, we need to examine where the fabrications are coming from, who the consumers are, why they give it credence and what can be done to convince them otherwise.

According to a paper by Kata, the origin of misinformation typically starts with valid scientific debate on the risks of vaccination. One would hope that debate would be based on honest data presented after a rigorous peer-review. Unfortunately, the fraudulent Lancet paper by Wakefield from 1998 (finally retracted by that journal in 2010 after 12 years of damage had already been done) calls even that assumption into question. From there, the debate is spun to conform to the anti-vaccination agenda and then reaches the public, typically through social media. (搜索 "Wakefield lancet 1998"，有不少關於那篇最初假論文的資料。)

Study Examines Common Traits of Anti-Vaccination Believers 研究他們的共同特徵
One question that needs to be answered is, “What traits do anti-vaccination believers have in common?” Hornsey et al. tackled this question and found some commonalities while dispelling a few stereotypes. Surprisingly, there seems to be no real correlation between vaccine attitudes and socioeconomic status or educational level. Much better predictors are a high level of conspiratorial thinking, a low tolerance to infringement on perceived personal freedom, aversion to needles or blood and religious issues. But most importantly, the consumers of misinformation are most commonly concerned parents. (高度的陰謀論思維，重視維護自己的自由，但最大的共同特徵是接受和享用錯誤消息。)

A large part of why people buy into the anti-vaccination mindset is confirmation bias; when presented with evidence opposing existing beliefs, patients and parents will reject the information out of hand. A German study demonstrated that subjects will perceive increased risk to vaccination after only five to ten minutes of time on an anti-vaccination websites. Additionally, a Canadian study suggested that the odds of parents perceiving vaccines as unsafe rose considerably for those who searched for vaccine safety information on the internet.7 Herein lies the problem: From the skeptical point of view, these websites present valid questions. From our point of view they are absurd and dangerous, but providing evidence for an absence of risk is painfully difficult. How can you expect to find common ground in this scenario, much less be persuasive? (提供疫苗沒有危險的證據挺難，證明沒有某事物永遠比證明有困難。)

Frustratingly, direct pro-vaccination messages may not be simply unhelpful, but can potentially backfire. Nyhan et al. found that not only did none of their four approaches to directly educate concerned parents with CDC-sourced pro-vaccination materials help, but also further reinforced the exaggerated perception of risk.8 The adversarial model that worked so well against the tobacco industry is unlikely to be helpful here. Moreover, nobody likes being lectured or talked down to, no matter how misguided their beliefs might be.

Education on the Consequences of Not Vaccinating 關於不接種後果的教育
Horne et al. tried a different approach; instead of directly taking on vaccine misinformation, experimental parent groups were educated on the consequences of not vaccinating their children. They had success with the group that was shown pictures of children with mumps and rubella, along with a letter from a mother of a measles patient. Disappointingly, a second group that was educated on the nonexistence of a vaccine/autism link remained as unconvinced as ever.

So we have evidence for an approach that potentially works for a select group of patients, but obviously much work remains to be done. On the individual level, I believe it has to come back to the doctor-patient relationship. Patients will continue to trust physicians who listen to their concerns. If we do not have that trust, we cannot reasonably hope to persuade on the real risks and benefits of vaccination. On the societal level, we need communicative physician leaders to engage the issue, not the activist. Rather than confrontationally going after anti-vaccination groups, physicians must clearly articulate a message on the consequences of being unvaccinated. (醫生患者之間的互相信賴關係很重要，可信的朋友也許有機會說服他們。)