What Does an Undetectable Viral Load Mean for HIV?


What Does an Undetectable Viral Load Mean for HIV?

Viral load is the amount of the human immunodeficiency virus (HIV) in someone’s system. If someone’s HIV status is undetectable, it means their viral load is so low that tests can’t measure it. Although they will still have a dormant version of the virus in their body (in what are called “viral reserves”), when someone has an undetectable viral load, they cannot give someone else HIV, even through unprotected sex.

The treatment for HIV is antiretroviral therapy (ART). It can take 3-6 months of being on ART to become undetectable. Most people who are being treated for HIV have an undetectable viral load. This means it’s very hard for them to pass on HIV. Most times that people get HIV, it’s from someone who isn’t on ART or doesn’t know they have it.

Is an undetectable viral load the same as not having HIV?

HIV is treatable, but not curable, so someone living with HIV will always have HIV. If they have an undetectable viral load, the virus is still in their body, in very low amounts. These low amounts stay in viral reserves, and can start reproducing again if treatment stops. So, an undetectable viral load doesn’t mean that someone is “cured” of HIV, or that they don’t have it anymore.

A person on ART has to keep taking their medication for their viral load to stay undetectable. If a person stops taking their medication or misses doses, their viral load may become detectable again. Other things like drug resistance, illness and vaccines can temporarily affect a person’s viral load. This is why regular visits to the doctor and testing are part of HIV care plans.

Can someone who’s undetectable still pass on HIV?

In 2016, the PARTNER study followed 1166 serodiscordant couples. This is a couple where one partner is HIV-positive and the other is negative. In each couple, one partner was on HIV treatment and had an undetectable viral load. There were both straight couples and gay male couples. Although, there were more straight couples. The couples were having sex without condoms. None of them used pre-exposure prophylaxis (PrEP) or post-exposure prophylaxis (PEP). These are medications that lower people’s risk of getting HIV. In total, the couples had penetrative vaginal or anal sex about 58,000 times. During the study, there were no cases of the undetectable person giving their partner HIV.

Recently, the PARTNER 2 study was published. The study was very similar to the first one. Except, it lasted eight years and only followed gay male couples.In total, the couples had sex 77,000 times without condoms. There were no cases of the undetectable person giving their partner HIV.

The PARTNER studies indicate that when someone has an undetectable viral load, they can’t give HIV to someone else through unprotected sex. Since then, these study results have been confirmed by numerous medical authorities. It is now commonly accepted by reputable HIV experts that it is impossible for someone with an undetectable viral load to give someone else HIV through unprotected sex.

Undetectable = Untransmissable or U = U

You may have heard the slogan “U=U”. It stands for “Undetectable = Untransmissable”. It is the slogan for the Prevention Access Campaign. The campaign was to promote the fact that someone who’s undetectable has almost no chance of passing HIV to someone else.

What does U=U mean for HIV decriminalization?

In Canada, if there is what’s called a “realistic possibility” of someone living with HIV passing the virus to their sexual partner, they legally have to say so. If they don’t, the person living with HIV could be charged with a crime, usually aggravated sexual assault. This can happen even if they don’t end up passing on HIV.

What counts as a “realistic possibility” can vary from province to province. In Quebec, if the person with HIV is using condoms and has a low or undetectable viral load, they don’t have to disclose that they’re HIV-positive. In all other situations of vaginal sex, they have to disclose it. This is because the court considers there to be a “realistic possibility” even if their viral load is undetectable — despite that not being in line with what medical experts know about HIV today.

When it comes to oral or anal sex, there are no definite rulings yet. The Supreme Court has not defined what counts as a “realistic possibility” for these acts.

I’m HIV-negative. What do I do if I’m not comfortable having sex with someone who’s undetectable?

It is always your choice whether to have sex with someone. There’s nothing wrong with choosing not to if you’re not comfortable with it. Choosing not to have sex with someone for any reason doesn’t make you a bad person.

Sometimes, learning more about how HIV is passed and what lowers the risk can help people feel more comfortable. Especially if HIV status is the only concern for you. In most cases where someone gets HIV, person who gave it to them didn’t know they were positive. So, just knowing your and your partners’ HIV status lowers the risk by a lot!

Still, many people’s fears around sex don’t have to do with the actual levels of risk. But these emotions can still have severe impacts on their sex lives. It’s okay to consider your feelings while deciding to have any kind of sex. It can help to have accurate, up-to-date information about HIV and how it passes from one person to another!

More info

Viral Load – AIDS.gov

Defines what a viral load is (for people living with HIV), what a normal viral load means, and what changes in viral loads mean. –

Info-Traitment (for HIV and Hep C)

A list of help lines and support programs for up to date information on HIV and Hepatitis C treatment in Quebec. Contact information is for one of several…


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