Vagina is the most terrifying word, the most threatening word, in any language of any country I have ever been to. Even when the vagina is worshipped in theory, as the yoni is in India, it is denigrated in practice. It is more reviled and feared than words like plutonium, genocide and starvation. In many countries the word for female genitalia is so derogative or disgusting, it cannot be spoken in public. In a few places, there is no word in the language for vagina at all.

As the vagina is the primary port of transmission from men to women of the Aids virus, how women and men perceive vaginas, talk about or don't talk about vaginas, how women know their vaginas, feel agency over their vaginas, determines everything about their future. Many women, even in so-called progressive countries, are still not comfortable asking a man out, acting directly on their own desire, be it for a man or a woman. Many women who are sexually active and educated about the virus are still, because of insecurity and embarrassment, having unsafe sex. Many women in the year 2010 do not know how their clitoris functions or how to give themselves pleasure, nor do they feel safe telling a partner or a husband what they need or that it hurts when they are entered without preparation or that it would all work much better if it happened slower.

For so many women in the world, because there is no open sex education, because women are discouraged from masturbation, because sex has been defined – like science or maths or business or politics – as something essentially male and belonging to men, sex is perceived as something foreign and inaccessible. Because women are regularly forced and taken against their will in parts of the world, sex has become associated with pain. It has become something you survive. Each year millions of women forcibly have their clitoris cut and removed. For many women, your vagina belongs to the clan, to the tribe, to the state, to the church, to the mosque, to the temple, to your husband. But it most certainly does not belong to you. So if it isn't yours, how do you protect it or cherish it?

You cannot prevent women from getting Aids without ending violence towards them, without shifting the dynamics of power. You cannot stop a disease that is being transmitted through sex unless you admit that sex exists, unless women have a right to sex and desire – the same way men have a right – unless women are equal active participants and not passive recipients of men's desires and thus the diseases men pass on through their narcissistic ejaculations. Until women know they have a right to refuse to be touched or entered and a right to invite it, a right to demand protection and a right to expect it, there will be no ending Aids. And until these rights are backed up by courts and enforced by states, women will never have those rights.

A man can get away with raping a virgin and saying he believes it will cure Aids, as long as there is a sanctioned and enforced environment of sexual ignorance. Creating a true and substantial dialogue about sex and sexuality means breaking taboos and asking questions. It means standing up to authorities like the church, which refuse to promote contraception and sex education. It means boldly speaking out against fundamentalist forces that promote abstinence, claiming it prevents Aids and STDs and early pregnancy when the data tells another story.

Frankly, nothing short of a worldwide sexual revolution will stop the spread of Aids. We need to dissemble the shame, reclaim pleasure, celebrate desire, human connection, skin and touch. We need to release the shackles of oppression, one-way enjoyment and narrow-minded education. We need open and fearless discussion allowing sex to be what it is – natural and beautiful.

The revolution will not happen without men. We need to create an environment where sexuality is more about connection than conquering, more about pleasure than performance. Men need to ask questions, and admit their vulnerabilities. They need to go slow and go deeper. Women need to expect this, demand it and allow a place for it.

The time is now. There are 33 million people living in the world with the HIV virus, about half of them women. I venture to say a good portion of them got the disease because there is no environment which supports them saying outright and directly, "Love my vagina".