(Photo: Vial with syringe via Shutterstock)

The controversy that has been swirling since late October around the World Health Organization’s (WHO) sudden about-face on the safety of the Depo-Provera injectable contraceptive is a mystery begging to be solved.

Countries rely on the WHO to give impartial advice on the safety of medicines. The expectation is that the agency will carefully scrutinize the available scientific evidence for and against a drug before it makes a policy recommendation, but in the case of Depo-Provera, the WHO appears to be forsaking science for the sake of special interests.

Depo-Provera has long been the subject of scientific debate. Produced by the pharmaceutical giant Pfizer, the progestin-only hormonal shot is given to women at three month intervals. While it’s highly effective in preventing pregnancy, Depo-Provera has a number of troubling side effects. These include prolonged and irregular bleeding, suppression of immune response, loss of bone mineral density in young women, significant weight gain, depression and loss of libido. Many women discontinue use because of these side effects. There are clear racial disparities in how Depo-Provera has been promoted. In the US, family planning providers mainly give it to young women of color. Globally, sub-Saharan Africa is a primary target.

For more than 25 years, scientific studies have provided compelling evidence that Depo-Provera significantly increases the risk of women and their partners becoming infected with HIV. A growing number of contraceptive researchers and epidemiologists now question the wisdom of promoting Depo-Provera, especially in places with a high HIV/AIDS incidence. A petition currently before the US Food and Drug Administration (FDA) requests that a warning about possible HIV risk be added to prescribing information about Depo-Provera. In South Africa, where about one-third of young women are HIV-positive, the government is taking steps to phase out Depo-Provera from its national family planning program.

Other scientific studies do not demonstrate a link between Depo-Provera and HIV, and so the issue remains unresolved. Until recently, the WHO cautiously occupied the middle ground. The agency’s 2014 guidance statement acknowledges the conflicting studies and offers this advice: “Given the importance of this issue, women at high risk of HIV infection should be informed that progestogen-only injectables may or may not increase their risk of HIV acquisition.”

Then suddenly in October this year, the WHO threw caution to the wind. In the absence of serious expert consultation, it issued new guidelines asserting that there is “no evidence of a causal association between DMPA [Depo-Provera] use and an increase in women’s risk of HIV acquisition.” This echoes Pfizer’s own statement that it “is not aware of any scientific evidence showing a causal association between use of hormonal contraceptives and an increase in HIV transmission rates.” In reality, there are a number of studies by well-known researchers in respected medical journals like the Lancet, Contraception and AIDS.

The WHO’s sudden about-face on Depo-Provera evidently took some members of its own Guidelines Development Group by surprise. Women’s health and HIV activists are alarmed. A coalition of 40 groups and advocates has just sent a letter to Dr. Margaret Chan, the WHO’s Director General, and Dr. James Kiarie, Coordinator of the WHO’s Human Reproduction Team, demanding with grave concern and urgency that the statement be removed from the WHO website and treated as a draft until it is put through “a rigorous consultative process.” The letter notes how the new language was developed, according to one official, “at the request of member states” who found the previous guidance “confusing.” Prominent South African women’s health advocate and consultant Marion Stevens, a research associate at the University of Cape Town’s African Gender Institute, has this to say:

The WHO’s change in its guidance on Depo Provera is very worrying. In South Africa we changed our fertility planning and contraception policy due to patterns emerging from research concerning HIV acquisition and Depo. It is deeply concerning that emphasis is put on prevention of pregnancy, essentially population control amongst poorer women, and deciding that this is more important than possible HIV transmission and acquisition. Health information should be put in women’s minds and hands.

The new WHO position is all the more shocking given that the agency is actually co-coordinator of a major clinical trial, called ECHO, in 12 African sites to assess whether Depo-Provera increases HIV risk or not.

Why is the WHO following in Pfizer’s footsteps? Why has it totally discounted the serious scientific studies that show a credible link between Depo-Provera and HIV? Why is it undermining its own ECHO trial? This is the mystery begging to be solved.

Detective work depends on informed speculation to decide which avenues of investigation are worthy of pursuit. In this case, timing may be everything. Depo-Provera is not only big business, but the technical fix du jour for reducing poor women’s fertility. Population control, unfortunately, is back in vogue.

In 2012, at the London Summit on Family Planning, a partnership of the Bill and Melinda Gates Foundation, Pfizer, the US Agency for International Development, the UK Department for International Development, the UN Fund for Population Activities and nonprofit PATH announced an initiative to reach 3 million women in sub-Saharan Africa and South Asia over the next three-year period with 12 million doses of a new subcutaneous delivery form of Depo-Provera called Sayana Press. Since that time, it’s been full speed ahead on Depo-Provera, with the Gates foundation at the helm.

Now sights are set on India. The Indian Ministry of Health recently announced that it has approved in principle Depo-Provera’s inclusion in the national family planning program. Concerned about the drug’s safety and suitability for Indian conditions, a coalition of health workers and activists is fighting back. It’s possible that the WHO’s October greenlight on Depo-Provera was timed to take the wind out of the protesters’ sails. Potentially, India is a huge market for the injection. Pfizer and its friends have much to lose if the government says no.

In the US, the FDA needs to respond shortly on the petition calling for a warning about the possible link between Depo-Provera and HIV. Was the WHO’s about-face designed to influence the FDA’s decision-making?

These issues and others warrant investigation. Was outside ‘encouragement’ applied to the agency to reverse its position on Depo-Provera? One hopes not, but the WHO receives a large share of its budget from voluntary contributions. The Gates foundation, for example, is the second largest donor to the agency after the US government. Donor money doesn’t always speak loudly, but it’s hard not to hear it whispering in your ear. Why did the WHO beat such a hasty retreat from evidence-based science? The scientists researching whether or not Depo-Provera increases HIV risk deserve to know. So do women’s health and AIDS activists. So does the public that puts its faith in the WHO to be an impartial judge.