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Young women have good adherence to PrEP vaginal ring and PrEP pills in 18-month trial

Hester Phillips

03 January 2024

When given the choice, two thirds of young women in East and Southern African trial opted for vaginal rings while one third chose daily pills – and adherence to both was higher than in previous studies

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Photos are used for illustrative purposes. They do not imply health status or behaviour. Credit: iStock/LaylaBird

A trial in South Africa, Uganda and Zimbabwe asked young women to try PrEP pills for six months then PrEP vaginal rings for another six before opting for a preferred method. The results show how essential choice is when it comes to PrEP. 

What is the research about? 

Young women’s use of the PrEP vaginal ring and oral PrEP. Around 250 adolescent girls and young women (ages 16-21) took part in the trial which ran between 2019 and 2021. One-third were aged 16–17.  

For six months, half used a PrEP ring and half took daily PrEP pills. Then the groups swapped over and used the other type of PrEP for six months. Then participants decided which type of PrEP they wanted to use for six months. Rings were provided monthly, as were PrEP pill refills. Participants also had access to adherence counselling.  

Why is this research important? 

Women in sub-Saharan Africa are disproportionately affected by HIV, particularly adolescent girls and young women. Women often struggle to get male partners to wear condoms, and PrEP provides an alternative HIV prevention method. The most common type of PrEP is oral PrEP. But some people find it hard to take a daily pill, so it is important to look at other PrEP options, such as vaginal rings. (PrEP can also come in injection form.) 

What did they find out? 

HIV risk  

At the beginning of the trial, around half the young women reported being very or somewhat worried about their HIV risk in the next year. One quarter of participants with a regular partner were unsure of their partner’s HIV status. Around one third had gonorrhoea or chlamydia. 


Adherence levels were the same for the PrEP ring and PrEP pills. For both, 57% of participants were highly adherent, and around 40% had some adherence. This is a higher level of adherence than other PrEP trials involving adolescent girls and young women. 


Both PrEP options were effective at preventing HIV. During the trial, four participants got HIV. But all four had PrEP levels in their body that indicated low or no PrEP use.  

Side effects  

Both PrEP options were safe and well tolerated, although one participant stopped taking PrEP pills due to side effects. For PrEP pills, there were 54 reports of moderate side effects (such as nausea and headaches) and 5 for the ring (such as vaginal discomfort and odour). 


At the beginning of the final six months, 65% of participants chose the ring, 30% chose PrEP pills and 5% chose neither. These choices remained fairly stable throughout the six months (58% continued with the ring, 26% continued with PrEP pills, 13% switched products, and 4% did not use either product). Adherence levels were similar to those during the trial’s first and second six months.  

What does this mean for HIV services? 

The results show how important it is to offer young women a choice, as different PrEP products are likely to suit different people. It also shows that young women can use PrEP consistently either as pills or vaginal rings over an 18 month period. 

Previous PrEP studies involving young women have not offered a choice of products and have not included monthly adherence support. This suggests that considering young women’s realities, needs and preferences is a strategy that works. Knowing what these needs and realities are means working with young women to co-design PrEP programmes.  

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