Nov 7

　　In September the AIDS community took a devastating blow when Merck halted an international human trial of the world's most promising potential vaccine against HIV. At the time, doctors revealed only that the vaccine—which uses an "adenovirus," or the common cold virus, to deliver HIV genes into the body—had not worked.

　　On Wednesday they began to explain why, releasing the first data from the trial, which was run by Merck, the HIV Vaccine Trial Network and the National Institute of Allergy and Infectious Diseases. The researchers announced a troubling finding: the number of HIV infections among the trial volunteers who received the vaccine was higher than the rate among those who received a placebo. Twenty-four of 741 volunteers who got the vaccine became infected with HIV, as did 21 in the placebo group.

　　失败的原因

　　今年9月，艾滋病研究因默克公司终止了世界上最有希望抵御艾滋病的疫苗的国际人体试验而遭受重大挫折。当时，医生们仅仅披露，使用“腺病毒”或者感冒病毒将HIV的基因植入人体的疫苗没有发生作用。

　　星期三，他们开始解释原因，并公布了第一批由默克公司、HIV疫苗试验网络和国家过敏和传染病研究院所做的试验数据。研究人员宣布了令人困惑的发现：接受疫苗的试验志愿者中，感染艾滋病病毒的人数比接受安慰剂的志愿者中受感染的人数要高。741名接受疫苗的志愿者中有24人受感染，而接受安慰剂的人中只有21人受感染。