Vaginal ring to help women prevent HIV

Dr Eunice Ouma, a researcher at Kemri displays the Dapivirine Vaginal Ring at the Kisumu County Referral hospital on 1st August. PHOTO| COURTESY

Kenyan women may soon have another weapon to prevent HIV infection, in the form of a vaginal ring containing the antiretroviral drug dapivirine.

The flexible silicon ring can be worn for a month, delivering 25 milligrammes of the anti-HIV drug in steady doses.

It reduces chances of HIV infection by 56 per cent, and is expected to protect women from the virus, without having to rely on men to wear condoms.

“Women often give in to sex without protection without knowing the status of their partner, unless the man initiates condom use himself. In many cases, married women give in for fear of gender violence,” explained Kemri researcher Dr Eunice Ouma, noting that the ring would protect women in such scenarios.

However, Dr Dismas Oketch, another Kemri researcher, emphasised that the ring only protects against HIV, so condoms would still be necessary to prevent other sexually-transmitted infections.


The ring is twisted and pushed up the vagina and positioned at the cervix where the vaginal walls hold it in place. After a month, it is changed with a new one.

It is comfortable and does not interfere with menses or intercourse, and might be more effective than PrEP pills which one may forget to swallow.

“HIV prevention is not a one-size-fit-all. One method may work for one person and not the other. That’s why there is research on several HIV prevention measures to provide options,” said Dr Ouma, noting that emerging methods will supplement condoms, abstinence, being faithful to one’s partner and the use of pre-exposure prophylaxis (PrEP). Some researchers are also working on a HIV-prevention injection.

Kemri is carrying out local trials on the vaginal ring, targeting healthy, uninfected girls aged 16 and 17 years and young women aged 18 to 21 years, who are on effective contraception.

At least 300 participants will be involved in the study, with 60 of them at the Kisumu Kemri site.

“Young women are more susceptible to HIV due to various reasons among them poverty and limited livelihood opportunities which lead to transactional sex; gender inequality and violence; limited availability of youth-friendly sexual and reproductive health services and biological vulnerability of the genital tract,” said Dr Ouma.

She added that the study would test for safety and tolerability and participants would not be exposed to HIV. Given that previous studies showed that the ring was embraced more by older women and not the younger ones, the researchers will also be seeking answers on what might affect acceptability of the ring among younger women.

Once the remaining stage of research is concluded, the research institute will get a licence from the Pharmacy and Poisons Board for the ring to be sold locally.


Antibody research

Researchers from Kemri and the US Centers for Disease Control and Prevention are conducting a pivotal study to evaluate the safety and efficacy of a type of antibody (VRC01), in reducing acquisition of HIV-1 infection in women in sub-Saharan Africa. Antibody Mediated Prevention (AMP) is a new technology that involves giving people antibodies passively to see if they will protect against HIV infection.

According to Dr Dismas Oketch, in traditional HIV vaccine studies, researchers wait to see if the body will make antibodies against HIV in response to HIV, but in this study, people will be given antibodies directly to evaluate whether antibodies can prevent HIV infection. The trial is taking place in 21 clinical research sites in seven African countries. It will enroll 2,000 sexually-active young women including 75 to 100 from Kenya.

Genetically modified rice can prevent HIV

Researchers have created a genetically modified strain of rice with virus-neutralising proteins that can prevent HIV infections.

The rice produces an antibody and two proteins that bind to the virus, thereby preventing them from interacting with human cells. The researchers note that once grown, the grains can be processed to make a microbicide with the HIV-neutralising proteins and people can grow as much rice as they need to make the microbicide.

However, further testing is needed to ensure that the genetic engineering process does not introduce modifications that might be harmful to humans. The findings were published in the journal PNAS.


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