Two recent articles in PLoS Medicine [1,2] criticise the role played by activists in raising concerns about the tenofovir trial for HIV prophylaxis. We fully support the fact that activism should be based on informed opinion, rather than speculation, unwarranted criticism, overreaction, or sensationalising facts [1], and believe that in Thailand, the concerns raised by activists are entirely legitimate.

The key community groups that have expressed concerns about the tenofovir trial in Thailand are the Thai Drug Users Network (TDN) and the Thai AIDS Treatment Advocacy Group ( TTAG), which are described in Box 1. These community groups, which can justifiably claim to represent Thai drug users, are well informed about the trial, but their objective concerns have been ignored by the trial investigators. Contrary to the assertion of Joep Lange [2] “that the investigators did consult intensely with community groups concerned”, TDN and TTAG were not consulted about the trial design and conduct until a very late stage, after several attempts to engage with the investigators had been rebutted. TDN and TTAG had attempted to constructively engage with the investigators since October 2004; they confined their statements of concern to private letters and meetings with the investigators, until the matter was made public in a Lancet editorial in March 2005 [3].

One major concern about the trial was the failure to provide sterile needles and syringes. Singh and Mills assert that this is consistent with Thai government policy [1]. Long prison terms and death sentences are the norm for drug-related offences [4], and Thai police, who have wide discretionary powers, still occasionally use possession of needles as evidence to arrest suspected drug users. Thus, although needles and syringes are available over the counter from most retail pharmacies, intravenous drug users (IDUs) are afraid to purchase them and, indeed, are often afraid to use services known to be provided for drug users. There is, however, no law or policy forbidding the distribution of clean needles and syringes, and preventing the investigators from doing so.

In fact, the situation in Thailand is improving, with the National Harm Reduction Working Group, chaired by the Ministry of Public Health, taking steps to increase activities in this domain. In 2004, at the 15th International AIDS Conference in Thailand, the prime minister said, “We are now implementing a harm reduction program to reduce the risk of HIV infection among injecting drug users…the program…will be conducted through concerted collaboration among solo UN agencies, government bodies and non-governmental organizations including the Drug User Network” [5].

The reason clean injection materials are not distributed within the trial is because the United States government, who sponsors the trial, bans federally funded organisations (including the Centers for Disease Control and Prevention, who are overseeing the trial) from supporting needle and syringe exchange.

Irrespective of whether a needle exchange exists in Thailand, or what the policies of the trial's funders are regarding needles and syringes, investigators have a duty to respect the Helsinki Declaration requirement that “benefits, risks, burdens and effectiveness of a new method should be tested against those of the best current prophylactic, diagnostic and therapeutic methods” [6].

The HIV/AIDS community in Thailand is not naive about the ethics of clinical trials: many have been directly or indirectly affected by previous AIDS drug trials in Thailand that have raised ethical concerns [7,8]. Nevertheless, TDN and TTAG have, from the beginning, made it clear that they support the development of innovative prevention tools to reduce the burden of global HIV, and would like this trial to go ahead.

We believe that the disagreements surrounding the tenofovir trial in Thailand would have been avoided if the investigators had set out to engage the community more openly, and if the wealth of established knowledge among community members could have contributed enormously to the success of the trial design and implementation. TDN and TTAG have made recommendations (see Box 1) that represent a constructive way for this trial to move forward. Mechanisms that ensure systematic involvement of legitimate representatives of the affected community as partners in research are the only way to ensure that future trials will proceed in a more productive way.