Characterization of HIV-1 Reservoirs in HIV+ Adolescents

Title: Characterization of Viral Reservoirs among HIV-1 non-B Vertically Infected Adolescents receiving Antiretroviral Therapy in Cameroon.

Acronym: AVIR-study, Adolescent viral reservoir

Importance and relevance Sub-Saharan Africa (SSA) is disproportionally affected with HIV/AIDS, with close to 70% of the global epidemics. With the highest burden of paediatric HIV infections, about nine out of every 10 children living with HIV found in the SSA region(1, 2). Adolescents and young people represent a growing share of people living with HIV worldwide. In 2019, about 1.7 million [1.1 million-2.4 million] adolescents between the ages of 10 and 19 were living with HIV worldwide representing about 5% of all people living with HIV, about 1.5 million [1.0 - 2.1 million] or 88% of HIV infected adolescent live in SSA. In 2019 alone, 460,000 [260,000-680,000] young people between the ages of 10 to 24 were newly infected with HIV, of whom 170,000 [53,000-340,000] were adolescents between the ages of 10 and 19. To compound this, most recent data indicate that only 27% of adolescent girls and 16% of adolescent boys aged 15-19 in Eastern and Southern Africa - the region most affected by HIV - have been tested for HIV in the past 12 months and received the result of the last test. The testing rates in West and Central Africa and South Asia are even lower. If current trends continue, hundreds of thousands more will become HIV-positive in the coming years, and without knowing their status, adolescents will miss out on life-saving treatment. Additionally, a large population of children infected with HIV perinatally over the last decade are growing into adolescence (3). Of the estimated 690,000 people who died of AIDS-related illnesses in 2019, 110,000 (or approximately 16%) of them were children under 20 years of age. (UNICEF global and regional trends, July 2020).

With the advent and scalability of Antiretroviral therapy (ART), there is a global decrease in AIDS-related deaths. As of the end of 2019, 25.4 million people were accessing antiretroviral therapy, representing 67% of all people living with HIV. However, only 53% of children living with HIV were receiving ART. Interestingly, about 94% of all children receiving ART are from SSA (4). In this context of continuous new HIV paediatric infections and increasing coverage in paediatric ART, the number of children living with HIV will increase, suggesting a higher likelihood of reaching adolescent age and even adulthood if treatment regimens remain fully effective in controlling HIV infection (3, 4). ADLHIV therefore constitutes an HIV population with growing health concerns and with very limited findings for generalizable best practices specific to this target population, especially in SSA.

Like several West and Central African countries, Cameroon is still faced with a generalized HIV epidemiology (2.7% prevalence) (5), with higher prevalence among pregnant women (5.7%) and HIV-exposed infants/children (5.8% [958/16,638] positivity at first PCR and 15% at the end of the PMTCT cascade) (6). As of June 2018, the national coverage of ART was 51.5% (281,083), which includes 12,362 children below 15 years of age (6). Regarding response to ART in Cameroon, we reported an overall rate of 79.4% viral suppression, with significant disparities across age ranges: 81.1% in adults, 75.6% in children, and only 53.3% in adolescent aged 10-19 years (7). Similar to UNAIDS reports, adolescents living with HIV (ADLHIV) represent the most vulnerable and underserved population in response to the epidemics(1, 5). For a safer growth toward adulthood, there is need to prioritize this population for the quest of innovative treatment strategies that ensure their well-being and their contribution for the development of SSA.