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什麼在愛滋預防上沒有人加入新推的預防性投藥

 [外文專譯] 為什麼在愛滋預防上沒有人加入新推的預防性投藥

作者:Christopher Glazek   
資料來源:The New Yorker (blog), October 1, 2013

Photograph by Jb Reed/Bloomberg/Getty

2010年11月,新英格蘭醫學雜誌發表了一項為期三年的臨床試驗中,由美國國家衛生研究院(N.I.H.)資助的結果,宣布到來的一種治療方法,可以減少感染愛滋病毒的風險超過百分之九十。此項治療涉及一種藍色、橢圓形含有emtricitabine和tenofovir的藥丸,市場上銷售的品牌名稱為Truvada。此藥在2004年由世界上最大的愛滋病毒藥物品牌生產商吉利德科學公司合成,已結合其他抗反轉錄病毒藥物作為治療愛滋病患的一個主要藥物。 N.I.H.研究小組發現,Truvada每天服用的劑量不僅抑制了感染者的病毒量,也在最初階段避免健康者感染愛滋病毒。繼N.I.H.後追蹤男同性戀者在秘魯、厄瓜多爾、巴西、南非、泰國和美國的調查研究,其他的試驗顯示該藥對異性戀男性和女性乃至於注射藥癮者皆是有效的。研究人員稱其為“暴露前預防”或簡稱PrEP。也有人把它稱為“新的保險套 ”。

在N.I.H.上宣布PrEP研究結果的當天,研究小組收到美國總統歐巴馬的祝賀電話。此後不久, 時代雜誌將PrEP列為其年度頂級醫療創新清單之首位。美國加州大學舊金山分校教授及國家衛生研究院此項研究的首席科學家羅伯特•格蘭特博士,已作好人群蜂踴而至的準備。他告訴我, “當我們宣布的前一天晚上,我們不得不與加州公共衛生的領導階層召開會議,他們的想法就如同我們所想的,這將會有點倉促,人們將湧向診所"。儘管事實上此時遠離美國FDA正式發出批准前一年多,疾病控制中心(C.D.C.) 仍制定了過渡期間的治療指引; C.D.C.知道有些醫生已未依藥品仿單開了Truvada的預防處方,並預計更會有一股跟風。

但是實際上藥物的採用一直很緩慢,據CDC流病部門生物醫學介入執行官員史密斯表示,至少有半數以上百萬的美國人是PrEP很好的候選人,他們透過性行為,是感染愛滋病毒的高危族群,但卻只有幾千美國人正在接受治療。“在大多數領域,許多醫生不希望成為第一個跨出大門者 ”史密斯說。聯合國愛滋病科學專家小組主席和愛滋病規劃署在南非研究中心的主任薩利姆•卡里姆,認為醫生的猶豫可能不會與性健康有什麼關係。“從根本上臨床醫生給健康者藥物就有困難 ”他說。“這並非對愛滋病是唯一的”;在此同時,儘管反復的證實Truvada的提供保護免受愛滋病毒的感染,但在這項研究結果被釋放時,估計仍約有一百五十萬美國人,其中的三分之一是當他們在十幾到二十來歲時就已成為愛滋病毒的感染者。

醫界不願意開具Truvada的處方,病人也不願意提出要求,源自於一場治療的苦戰。批評者質疑PreP的安全性、有效性和成本,並指責在公共衛生支出上政府與藥品產業串通。理根•霍夫曼,愛滋病感染者雜誌Poz的前首席主編,稱PrEP為“富有西方人利益導向的性玩具。愛滋病保健基金會( A.H.F.)-世界最大的愛滋病組織及全球各地兩百多萬患者初級照護的提供者其領導人邁克爾•溫斯坦,則預測為一個公共衛生災難。“這種做法所獲得的掌聲,說明了我們是多麼地認為男同性戀者的生活是可拋棄的 ”他寫道。當我採訪了溫斯坦,他宣稱這研究是“人為操控製造”的, PrEP基本上是一個由吉利德公司策劃以迫使年輕人購買不必要的藥物,且未來會更糟因為A.H.F. 並沒有讓製藥公司擺脫它。

這類說法有助於塑造病人、醫生和記者之間對此藥物的看法。在2012年5月F.D.A. 的一個開放性公聽會,滿載的A.H.F.員工們出現在會場聲明反對PrEP,他們提出了有關藥物的副作用、它的價格、激發危險行為的潛力、無法預防其他的性病、未完全遵從醫囑按日服藥的潛在問題導致抗Truvada病毒株散播的可能等。雖然從研究的數據上有很大程度反駁了這些批評,但它們已被廣為流傳。"我覺得A.H.F. 的宣傳是非常有效的",溫斯坦告訴我,“我們所寫的每一篇文章幾乎都被引述。 ”

Gilead公司對促進Truvada作為 PrEP治療的努力已有些不足。“在任何其他種類經F.D.A.批准的藥物,都有漂亮的廣告、大量的電視、和大量的新聞推銷其事實,說明這是新的東西,可保護人們免受愛滋病毒的侵害",舊金山愛滋病基金會立法事務總監的歐內斯特•霍普金斯表示。根據吉利德的醫療事務副主席吉姆•魯尼所說“吉利德選擇不這樣做 ”,該公司已“花費數百萬美元” 透過第三團體進行有關PrEP的教育推動,但它“並未視PrEP為商業機會"。 對吉利德公司而言,“ Truvada"早已是一個重型炸彈般藥物,光2012年在全球銷售就贏得超過3億美元。正如魯尼指出,“抗反轉錄病毒藥物用作愛滋病毒的預防角色尚未經定義,尚未被廣泛接受"。雖然吉利德已經捐贈藥品到工作於PrEP的研究人員,但並未展開自己的研究。根據芝加哥愛滋病基金會宣傳預防部主任吉姆•皮克特表示, “製藥公司不得不被拖入新的預防研究,對此他們並不是很興奮,他們並不想這樣做"。

***
PrEP的主要問題是許多公共衛生官員認為,人們會視它為一個保險套替代物。 Out雜誌當它在9月初刊出一篇對PrEP正向報導稱“這是新的保險套嗎?"時挑起了反彈,評論者斥責作者蒂姆•墨菲,並控訴該雜誌不負責任地促進一個未經證實的藥卻以犧牲保險套作為代價

不幸的是,格蘭特指出,當涉及愛滋病預防時對保險套成效的認知事實上“超過其公共衛生的價值”。根據CDC的史密斯表示,保險套當它們一致地被使用時的確提供高度保護,但數據顯示,很少有人一致地使用它們致足以產生一個實質的效益;以及當人們被反復提問如果在一段較長的時間他們使用保險套情形時,其自我報告使用保險套比率即急劇的下降。根據疾病預防控制中心的數據分析,有時偶而使用保險套的人和那些永遠不會使用到它們的人們,其保護水平的差異並未達統計學上意義。

相對應於保險套,PrEP的對應數字更好,然而服藥順從性是一個問題; Truvada在提供愛滋病預防的保護上比禁慾外任何其他方法更為有效。例如在N.I.H.研究中,安慰劑組的血清轉換率為5.2% 或轉變為愛滋病陽性, Truvada組則為2.9 %。這是一個44 %的附加保護,優過於不一致地使用保險套。更令人印象深刻的是,患者如在他們的系統中保持可檢測的藥量則亦有95 %的保護率。 (稍後的統計分析估計,該藥物將需要採取每週四次,在這個範圍內提供保護 );格蘭特說明,研究中的人們若服用該藥達每週四到七天者,“則為絕對保護"。在美國我們沒有看到在我們研究的觀察世代中有任何人血清陽轉。 “

服用Truvada預防H.I.V.有極少的風險。在N.I.H. 研究,兩百分之一的人不得不暫時因腎臟問題而停藥,但即使是那些人也能夠在幾個星期之後繼續恢復了治療。雖然骨密度流失偶爾發生在在那些已經感染了愛滋病毒的Truvada使用者,但沒有顯著的骨問題已出現在PrEP的研究中。雖然大約有十分之一使用者在治療初期感覺噁心,但它通常幾個星期後消散。根據聯合國愛滋小組的卡里姆表示, Truvada的副作用的概況是“了不起的 ”;此外格蘭特說,常見的日常藥物,如阿司匹靈和避孕藥,以及控制血壓和膽固醇的藥物,都可以說是比Truvada更具毒性的。

或許更重要的是,目前HIV陰性的人當他們開始治療並沒有觀察到抗藥性。  “格蘭特說: ”我們沒有看到真正服用藥物的人致感染。 “有些人將藥帶回家,並選擇不吃藥,他們遭愛感染,但你不會由留在抽屜裡的東西而得到抗藥性”。有些病人在進入實驗時已感染愛滋病毒,是經由最近驗血被檢出。這些個案顯示少數的抗藥性,這就是為什麼美國FDA要求醫生,在他們把病人加入PrEP之前應進行H.I.V.的測試。因此,較大的抗藥性威脅,主要來自世界各地上千萬HIV陽性已採抗病毒藥物治療的人們,其中有某些個案使用包括Truvada的藥物。 “防止抗藥性的最好辦法是徹底地預防愛滋病毒感染"格蘭特說。"我們知道當我們在避免了愛滋個案產生的情況下,我們也終身避免了抗藥性的風險。 ”

是否使用PrEP會導致感染者放棄使用保險套,並增加他們的性伴侶數仍是未知數。格蘭特堅持,相關證據確實不支持這樣的結論:“每個人都表示,如果我們提供暴露前預防給人們,甚至採隨機分派試驗就如我們所執行的研究一般,它只是會導致他們擁有更多的性伴侶,並停止使用保險套"。 我們卻發現相反結果,人們反而減少性伴侶,並更加使用保險套。話又說回來, PrEP的主要研究參與者獲得免費的保險套和定期性健康輔導,他們也可能對他們的性行為不說真話。,哈佛醫學院教授和貝斯以色列醫學中心艾滋病毒預防研究主任肯•邁耶認為,一些人遠離保險套而朝向Truvada的遷移是不可避免的,但它不一定是一個壞的權衡, 從PrEP的功效和事實上許多持續在治療中的人可能橫豎他們始終都不使用保險套呢。而在我與目前在PrEP的這些人交談的此一區塊中,大多數正在尋求PrEP的這些人,並不是因為他們想放棄保險套,而是因為他們早已經沒有使用它們了。 CDC的治療準則強調, PrEP的是除了使用保險套外其他應採取的措施,因為PrEP不能防止其他性病。

成本問題,至少在美國,比起最初預計的也已變成為一個較小的關注。史密斯說,“我們很驚訝地發現,保險公司說,是的,我們會為它付出;治療愛滋病毒感染者的費用更昂貴 "。然而仍有許多人處在感染愛滋病毒的高風險狀態,目前卻缺乏醫療保險, 1月1日之後,許多人會能夠得到歐巴馬總統Obamacare的涵蓋範圍;而對於那些還沒保險或無法支付部份負擔的人,Gilead公司則提供援助去購買藥物,以定價為13000美元提供一年。

***
然而,在發展中國家,甚至提供便宜的Truvada的仿製藥都可能是一個挑戰,目前還不清楚,廣泛的分流資源在預防是否有道理。愛滋病疫苗倡導聯盟執行董事米切爾•沃倫指出,無論如何同樣的反對論點也曾出現在使用抗反轉錄病毒藥物在治療過程中。 “十年前,人們說你不能在非洲提供治療:他們不會順從服藥,它太昂貴了,它會產生抗藥性 ”他說;“許多這些問題已經得到滿足,雖然他們還沒有完全被克服,但現在我們已有上千萬人在治療”。 讓PrEP變成可行,尤其是在撒哈拉以南非洲地區以保護年輕婦女,卡里姆說,“是實現一個無愛滋年代所不可或缺的"。

由於愛滋病毒陽性者服用抗反轉錄病毒藥物可大幅減少傳播風險,愛滋病蔓延比以往來得慢。A.H.F. 的溫斯坦 ,是第一次嘗試將抗反轉錄病毒藥物帶入非洲的先鋒者之一,他指出,今天在世界各地有上千萬的人們在抗反轉錄病毒藥物治療中,大部分要歸功於喬治•布希總統的全球愛滋倡議。 "如果我們可以增加一倍,至2000萬 ”他說,“我認為我們將可讓HIV在控制之中"。因此人們可以得出一個結論,那就是Truvada的用於預防便是這一概念的延伸。

然而其中一個問題是, PrEP的倡導它缺乏一個固有的擁護者。“行動聯盟(ACT UP) 僅集中於對愛滋病感染者關注",梅爾說。反對PrEP者的聲音已經很響亮且持久,而PrEP它的支持者卻往往是態度較莊重且謹慎小心的。他們指出,許多對Truvada所提出的論點,是六十年代和八十年代禁慾的支持者在反對生育控制時對保險套所提出的相同論點。格蘭特說:“這需要很長的時間,尤其當它是一個涉及性行為的醫療介入措施"。 Gilead公司預測,這在美國將需要五到十年的時間讓PrEP達到成為被廣泛使用狀態, 屆時Truvada將可能已失去專利保護。

當OUT雜誌的文章出版和隨後接踵而至的反彈聲浪後,我再次與芝加哥愛滋病基金會的皮克特通訊時,他否認一些先前有關在PrEP上的熱情。反對者需要了解的是什麼,他說, “沒有人真正設想將Truvada廣泛的用作為預防性治療;這確實是一個有利基的介入措施,它應該針對目標非常有策略性地使用,但沒有人願意將它交給重點族群的每個人"。當出刊時,他澄清說,他認為Truvada是適用在有高風險行為但卻又掙扎於單純性伴侶或堅持使用保險套困擾中的人,而單單在美國大體估計就似乎有數以百萬計的人。

雖然對PrEP遲疑的看法不用說會隨著時間的推移而退去,但此刻仍依然強勁。當最近我與一個住在布魯克林區曾聽我談論PrEP的26歲城市規劃師交談時, “噢,是的 ”,他面帶愁容地說,“我曾聽說了這議題,我在OUT上看到相關訊息;它說,這是行不通的,對不對?"。

以下原文

Why Is No One On the First Treatment To Prevent H.I.V.?
Posted by Christopher Glazek

 
In November, 2010, the New England Journal of Medicine published the results of a three-year clinical trial, funded by the National Institutes of Health, announcing the arrival of a treatment that could reduce the risk of contracting H.I.V. by more than ninety per cent. The treatment involved a blue, oval pill containing emtricitabine and tenofovir. Marketed under the brand name Truvada, the pill was synthesized in 2004 by Gilead Sciences, the world’s largest producer of branded H.I.V. drugs, and has been used in combination with other antiretrovirals as a primary treatment for people living with AIDS. The N.I.H. team discovered that a daily dose of Truvada not only suppressed the virus in people who were already infected but also prevented healthy people from contracting H.I.V. in the first place. Following the N.I.H. study, which tracked gay men in Peru, Ecuador, Brazil, South Africa, Thailand, and the United States, additional trials showed the drug to be effective for heterosexual men and women, as well as for injection-drug users. Researchers called the treatment “pre-exposure prophylaxis,” or PrEP for short. Others have called it “the new condom.”

On the day the N.I.H. announced the results of the PrEP study, the research team received a congratulatory phone call from President Obama. Shortly thereafter, Time put PrEP in the first slot on its list of the year’s top medical innovations. Dr. Robert Grant, a professor at the University of California San Francisco and the N.I.H. study’s lead scientist, braced for a stampede. He told me, “The evening before we announced, we had meetings with the leadership of public health in California, and they were thinking, as we were, that there was going to be a rush, that everyone was going to descend on the clinics.” The Centers for Disease Control issued interim usage guidelines, despite the fact that the treatment was more than a year away from formal F.D.A. approval. The C.D.C. knew that some doctors were already prescribing Truvada for prevention off-label, and it expected more to follow suit.

But, in fact, adoption of the drug has been slow. According to Dawn Smith, a biomedical interventions implementation officer in the C.D.C.’s epidemiology branch, at least half a million Americans are good candidates for PrEP—meaning that they are at high risk for contracting H.I.V. through sexual activity—yet only a few thousand Americans are receiving the treatment. “As in most fields, many clinicians don’t want to be the first one out of the gate,” Smith said. Salim Karim, the chair of United Nations’ AIDS Scientific Expert Panel and the director of the Centre for the AIDS Programme of Research in South Africa, thinks that doctors’ hesitance may not have anything to do with sexual health. “Clinicians fundamentally have difficulty giving healthy people drugs,” he said. “This is not unique to H.I.V.” Meanwhile, despite repeated demonstrations that Truvada provides protection from H.I.V., an estimated hundred and fifty thousand Americans, more than a third of whom are in their teens and twenties, have become infected with the virus since the results of the study were released.

The medical community’s reluctance to prescribe Truvada—and patients’ reluctance to request it—also stems from a bitter fight over the treatment. Critics have questioned PrEP’s safety, efficacy, and cost, and have accused the government of colluding with the drug manufacturer at the expense of public health. Regan Hofmann, the former editor-in-chief of Poz, a magazine for people living with AIDS, called PrEP a “profit-driven sex toy for rich Westerners.” Michael Weinstein, the head of the AIDS Healthcare Foundation (A.H.F.), the world’s largest AIDS organization and the primary-care provider for more than two hundred thousand patients around the world, predicted a public-health catastrophe. “The applause for this approach shows just how disposable we consider the lives of gay men,” he wrote. When I interviewed Weinstein, he claimed the studies were “rigged” and that PrEP was essentially a plot by Gilead to force young people into buying unnecessary medication, and that it was going badly because A.H.F. wasn’t letting the company get away with it.

These kinds of claims helped to shape perceptions of the drug among patients, doctors, and journalists. At an open F.D.A. hearing in May, 2012, busloads of A.H.F. employees showed up to make statements against PrEP, raising questions about the drug’s side effects, its price tag, its potential to incite risky behavior, its failure to prevent other S.T.D.s, and the possibility that imperfect adherence to the pill’s daily regimen would lead to the spread of a Truvada-resistant strain of H.I.V. Though data from the studies largely contradicts these criticisms, they were widely circulated. “I think the advocacy that A.H.F. did was very effective,” Weinstein told me. “We were quoted in virtually every article that was written.”

Gilead’s efforts to promote Truvada for PrEP treatments have been somewhat meagre. “In any other kind of F.D.A. approval, there would have been beautiful ads, lots of TV, and lots of press touting the fact that this was the new thing to keep people protected from H.I.V.,” said Ernest Hopkins, the director of legislative affairs for the San Francisco AIDS Foundation. “Gilead chose not to do that.” According to Jim Rooney, Gilead’s vice-president of medical affairs, the company “spends several million dollars” on educational initiatives related to PrEP, delivered through third-party groups, but it “does not view PrEP as a commercial opportunity.” Truvada is already a blockbuster drug for Gilead; it earned the company more than three billion dollars in global sales in 2012. As Rooney notes, “The role of antiretrovirals in H.I.V. prevention is not yet defined and not yet broadly accepted.” Although Gilead has donated drugs to researchers working on PrEP, it has not undertaken its own study. According to Jim Pickett, the director of prevention advocacy at the AIDS Foundation of Chicago, “Pharmaceutical companies had to be dragged into new prevention research. They weren’t excited about it. They didn’t want to do it.”

* * *
PrEP’s main problem is that many public-health officials believe people will see it as a substitute for condoms. Out magazine provoked a backlash when it printed a positive report on PrEP in early September, called “Is This the New Condom?” Commenters berated the author, Tim Murphy, and accused the magazine of irresponsibly promoting an unproven medicine at the expense of condoms.
Unfortunately, as Grant points out, when it comes to preventing H.I.V. the perceived efficacy of condoms “exceeds their public-health value.” According to the C.D.C.’s Smith, condoms provide a high degree of protection when they’re used consistently, but data shows that very few people use them consistently enough to derive a substantial benefit, and self-reported condom use falls precipitously when people are asked repeatedly if they’re using condoms over an extended period of time. In the data analyzed by the C.D.C., the difference in protection levels for those who sometimes use condoms and those who never use them was not statistically significant.

The corresponding figures for PrEP are much better: while adherence is a concern, as it is with condoms, Truvada offers H.I.V. protection that is more effective than any other method short of abstinence. In the N.I.H. study, for example, 5.2 per cent of the placebo group “seroconverted,” or became H.I.V. positive, compared with 2.9 per cent of the Truvada group. That’s a forty-four-per-cent added protection over-all—better than inconsistent condom use. More impressively, patients who maintained a detectable amount of the drug in their system were protected at a rate of ninety-five per cent. (A later statistical analysis estimated that the drug would need to be taken four times a week to offer protection in that range.) Grant said that people in the study who took the drug four to seven days a week “were absolutely protected. We didn’t have anyone seroconvert in our cohort in the United States.”

Taking Truvada to prevent H.I.V. comes with very few risks. In the N.I.H. study, one in two hundred people had to temporarily go off the pill owing to kidney issues, but even those people were able to resume treatment after a couple of weeks. While bone-density loss occasionally occurs in Truvada takers who are already infected with the virus, no significant bone issues have emerged in the PrEP studies. And though about one in ten PrEP takers suffer from nausea at the onset of treatment, it usually dissipates after a couple of weeks. According to the U.N. panel’s Karim, Truvada’s side-effects profile is “terrific,” and Grant said that common daily medications like aspirin and birth control, as well as drugs to control blood pressure and cholesterol, are all arguably more toxic than Truvada.

Perhaps more important, drug resistance has not been observed in people who were H.I.V.-negative when they began treatment. “We’re not seeing people getting infected who are actually taking the drug,” said Grant. “There are people who take the drug home with them and choose not to take it; they get infected, but you’re not going to get drug resistance from something that stays in a drawer.” Some patients who entered the trials turned out to already have an H.I.V. infection that was too recent to be caught by a blood test. These subjects showed a small amount of drug resistance, which is why the F.D.A. now requires doctors to conduct an H.I.V. test before putting their patients on PrEP. The larger resistance threat, though, comes from the ten million H.I.V.-positive people around the world who take antiretrovirals for treatment, including, in some cases, Truvada. “The best way to prevent drug resistance is to prevent H.I.V. infection entirely,” said Grant. “We know that when we prevent a case of H.I.V., we’re preventing a lifelong risk of drug resistance.”

Whether using PrEP will cause patients to abandon condoms and increase their number of sexual partners isn’t known. Grant insists that the evidence does not support such a conclusion: “Everyone said that if we offer pre-exposure prophylaxis to people, even in a randomized trial, like we did, it’s just going to cause them to have more sexual partners and stop using condoms. We found the opposite: that people had fewer sexual partners and used condoms more.” Then again, participants in the major PrEP studies received free condoms and regular sexual-health counselling. They also may not have been telling the truth about their sexual practices. Ken Mayer, a professor of medicine at Harvard Medical School and Director of H.I.V. Prevention Research at Beth Israel Deaconess Medical Center, believes that some migration away from condoms and toward Truvada is inevitable, but that it wouldn’t necessarily be a bad trade-off, given PrEP’s efficacy and the fact that many of the people likely to go on the treatment don’t use condoms anyway. This squares with my own conversations with people on PrEP: most of them are seeking PrEP not because they wish to abandon condoms but because they already don’t use them. The C.D.C.’s usage guidelines stress that PrEP is something to be taken in addition to using condoms, since PrEP doesn’t protect against other sexually transmitted diseases.
Cost, at least in the United States, has also turned out to be a smaller concern than initially predicted. Smith said, “We were very surprised to find out the insurance companies said, ‘Yes, we’ll pay for it. It’s much more expensive to treat people who have H.I.V. infections.’ ” While a lot of people at high risk for contracting H.I.V. currently lack health insurance, after January 1st many of them will be able to get coverage through Obamacare. And for those who still don’t have insurance or who have unmanageable co-pays, Gilead provides assistance to purchase the drug, which has a sticker price of thirteen thousand dollars a year.

* * *
In the developing world, however, where even delivering cheap generic versions of Truvada can be a challenge, it remains unclear whether diverting resources to prevention on a wide scale makes sense. Mitchell Warren, the executive director of the AIDS Vaccine Advocacy Coalition, points out, however, that the same argument was once made against using antiretrovirals for treatment. “Ten years ago, people said you couldn’t provide treatment in Africa: people wouldn’t adhere, it was too expensive, it would create resistance,” he said. “Many of those issues have been addressed—they haven’t all been overcome—and now we have ten million people on treatment.” Making PrEP available, particularly to protect young women in sub-Saharan Africa, said Karim, “is essential to achieving an AIDS-free generation.”

Because H.I.V.-positive people who go on antiretrovirals have a drastically reduced risk of transmission, AIDS is spreading more slowly than it used to. Weinstein, of the A.H.F., was among the first to attempt to bring antiretrovirals to Africa. He pointed out that there are ten million people around the world on antiretrovirals today, mostly thanks to George W. Bush’s global AIDS initiative. “If we can double that to twenty million,” he said, “I think we will have brought H.I.V. under control.” Truvada for prevention, one might conclude, is an expansion of that concept.

One of the problems is that PrEP lacks a built-in constituency to advocate for it. “ACT UP is focussed on people already living with AIDS,” said Mayer. And while the opponents of PrEP have been loud and persistent, its supporters tend to be stately and circumspect. Many of the arguments made against Truvada, they note, are the same arguments that proponents of abstinence lodged against birth control in the sixties and against condoms in the eighties. “It takes a long time when it’s a medical intervention that has to do with sexual practices,” said Grant. Gilead predicts that it will take five to ten years for PrEP to become widely used in the U.S., by which time Truvada could be off-patent.

When I corresponded again with Pickett, of the AIDS Foundation of Chicago, after the publication of the Out article and the ensuing backlash, he appeared to disavow some of his enthusiasm regarding PrEP. What opponents needed to understand, he said, was that “no one was really envisioning widespread use of Truvada as PrEP. It really is a niche intervention—which should be targeted and used very strategically. No one wants to hand this out to everyone in a key population.” When pressed, he clarified that he thought Truvada was for anyone in a high-risk group who struggled with monogamy or consistent use of condoms, a delineation that would seem to include millions of people in the United States alone.
While skepticism about PrEP will undoubtedly recede over time, for the moment it remains strong. I was recently speaking with a twenty-six-year-old urban planner living in Brooklyn, who overheard me talking about PrEP. “Oh yeah,” he said, with a worried look. “I’ve heard of that. I saw that piece in Out. It said it doesn’t work, right?”

Photograph by Jb Reed/Bloomberg/Getty
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