ATN History Cycle 1 - The Adolescent Medicine Trials Network

ATN Era #1

2001-2006

In 2001, the ATN was established as the first and only HIV research network in the U.S. dedicated solely to adolescents & young adults. Many of the youth-centered and community-based methods developed in this period have remained core features of ATN research.

A note on study titles: Some ATN studies use language that’s now outdated or have long titles full of scientific jargon because they were named for researchers instead of young people. In more recent eras of the ATN, we try to create youth-friendly titles.

To stay true to our history, we’ve kept the original study names but included plain-language study descriptions to make them easier to understand.

1996

ATN 000: REACH

1996-2000

ATN 000 Reaching for Excellence in Adolescent Care and Health (REACH) was one of the first major U.S. studies to focus on how HIV affects young people, and how social, behavioral, and mental health factors influence health outcomes.

The observational cohort study followed both adolescents living with HIV and adolescents without HIV but considered to have a high chance of acquiring HIV. The findings laid the groundwork for the ATN’s youth-focused research.

2001

The Adolescent Medicine Trials Network is Launched by the National Institutes of Health

ATN Cycle 1: 2001-2006

Innovation

Young people are disproportionately affected by HIV but often underrepresented in research. Youth have distinct developmental, social, and healthcare needs.

To address the need for treatment and prevention strategies designed specifically for youth, the National Institutes of Health (NIH) created the ATN to bring together youth, researchers, healthcare providers, and communities.

Why It Matters

The ATN is the only HIV research network in the United States dedicated solely to adolescents and young adults, ensuring that young people’s unique needs are not overlooked in research.

ATN 016: Connect to Protect (C2P)

2001-2006

C2P spanned two ATN funding cycles and focused on creating lasting change in environments and systems, rather than changing individual behavior. The first phase of C2P identified community partners, prioritized demographic groups, and identified physical locations where youth congregated in order to organize community coalitions to plan interventions for structural change.

2003

2003-2004

Focused on helping teens make informed decisions about research participation. The study tested whether simpler forms and pictures could make complicated topics—like HIV vaccine research, risks, and benefits—easier for young people to understand.

ATN 015

2003-2006

Study Title
Short-Cycle Therapy in Adolescents Following Continuous Therapy with Established Viral Suppression

Explored whether young people living with HIV could take planned breaks from their HIV medication each week and still keep the virus under control. While some participants were able to maintain viral suppression, over a third of participants experienced increases in their viral load and had to return to daily treatment, showing that this approach was not a good fit for everyone.

ATN 021A

2003-2005

ATN 021A: Prevalence of Morphologic and Metabolic Abnormalities in HIV Infected and Uninfected Young Women looked at how HIV and HIV treatment can affect overall health beyond just controlling the virus.

Researchers looked at body composition, bone strength, and cholesterol levels to identify potential long-term health effects and ways to improve care for young women living with HIV.

ATN 026

2003

Study Title
Evaluation of HIV-Specific CD8+ T-Cell Responses and Escape Mutations as Explanations for the Observed Differences in Disease Progression Conferred by HLA Class I Alleles

Looked at how a person’s immune system can influence the way HIV progresses. By studying youth with specific genetic traits linked to stronger or weaker HIV control, researchers learned more about how the body fights HIV and how the virus changes to escape those defenses.

2004

ATN 020

2004-2005

Study Title
Identity Development in Gay/Bisexual/Questioning Male Youth: Implications for HIV Sexual Risk

At a time when most HIV research focused on behaviors, ATN 020 looked at the broader experiences shaping young people’s lives. The findings helped researchers better understand how identity, stigma, community connection, and personal development can influence health and HIV prevention among gay and bisexual men.

FDA Approved Truvada as Treatment for People Living with HIV

The FDA approved Truvada (emtricitabine/tenofovir) was approved for use among teens and adults as treatment for HIV-1. It is used in combination with other antiretroviral medications to lower the amount of the virus in the body and increase CD4 cells, which are your immune system’s ultimate defense squad.

Why It Matters

Before this approval, managing HIV often meant juggling a “cocktail” of medications every day. Approval marked a shift toward simplifying HIV treatment into a once-daily single tablet, becoming the foundational backbone for HIV care and making it easier for people to stay healthy.

ATN 024

2004-2008

Study Title
A Randomized, Open-Label Trial of Three Hepatitis B Vaccination Schemas in HIV-Positive Youth

ATN 024 helped answer an important question: how can we make hepatitis B vaccines work better for young people living with HIV? Youth living with HIV may not respond as well to vaccines as others.

ATN 024 followed 371 youth living with HIV for up to 72 weeks after vaccination. The study found that higher-dose vaccines and a combined hepatitis A/hepatitis B vaccine helped more participants develop protection against hepatitis B than the standard vaccine approach.

ATN 025

2004-2008

Study Title
Hepatitis B Vaccination in Youth at ATN Sites: Effectiveness of Two Strategies and Evaluation of Tools to be Used in Future HIV Prevention Trials

ATN 025 looked at ways to better protect young people from hepatitis B, a virus that can damage the liver. The study compared two vaccines among youth with an increased likelihood for acquiring HIV. The study also helped researchers learn how to make future HIV vaccine studies more youth-friendly by understanding what teens think about research participation and consent forms.

2005

ATN 004: Healthy Choices

2005-2006

Tested a counseling program that used motivational interviewing to help young people living with HIV think about their health, relationships, and future goals. Through supportive conversations with counselors, participants learned skills that could help them make healthier choices, stay safer, and take better care of themselves.

ATN 012: Family-Based HIV Prevention for Adolescent Females

2005-2006

Tested a family-centered program that helped teen girls and their parents talk more openly about relationships, sexual health, and making safer choices, with the goal of helping teens stay healthy and protected.

ATN 023

2005-2006

Study Title
Typology of Adherence in Adolescents: Phase II

Identified the most common barriers that prevent young people from consistently taking HIV medication, helping researchers develop more effective, youth-centered adherence support programs.

2005-2006

This study tested a new approach to HIV and STI prevention by working with groups of friends instead of individual teens. The study recruited adolescents and their social networks into small group sessions that focused on reducing certain sexual behaviors that could lead to HIV and STIs, increasing condom use, and helping young people make safer choices around sex and substance use.

ATN 034: PROJECT ÒRÉ

2005-2006

Study Title
PROJECT ÒRÉ: An Innovative Friendship Based HIV/STI Intervention for High Risk African American Females

PROJECT ÒRÉ tested a culturally tailored HIV/STI prevention program for African American adolescent girls. Instead of working with individual participants, the program brought together groups of friends for interactive workshops focused on healthy relationships, communication, safer sex, and HIV/STI prevention.

The results showed that the program had positive effects that varied by age group:

Younger participants were more likely to get tested for HIV
Older participants reported less risky sexual behavior after the intervention
Participants in the middle age bracket reported fewer sexual partners.

ATN 039

2005-2006

Examined behavior, healthcare experiences, and barriers to accessing services among young people from an underserved population. Through surveys and interviews, researchers sought to better understand the challenges youth face in order to inform future HIV prevention and care efforts.

ATN 048

2005-2007

Study Title
Correlates of HBV-Specific B Cell Memory Following Vaccination in HIV-Infected Adolescents and HIV-Uninfected Adolescents: A Substudy of ATN 024 and ATN 025

ATN 048 was a laboratory substudy of ATN 024 and ATN 025 that looked at what happens inside the immune system after hepatitis B vaccination. Researchers wanted to understand why some adolescents developed strong, long-lasting protection from the vaccine while others did not. They studied immune cells and antibody responses in both youth living with HIV and youth without HIV.

The study found that differences in B-cell memory and other cellular immune responses were linked to whether adolescents developed and maintained protection after hepatitis B vaccination. In other words, some young people created stronger long-term immune memory than others, helping explain why vaccine responses can vary.

ATN 052

2005-2008

Study Title
Population Genetics and Immune Response to Hepatitis B Vaccination in Adolescents: A Substudy of ATN 024 and ATN 025

Studied data from participants in ATN 024 and ATN 025 to learn more about how genetic differences affect hepatitis B vaccine response in adolescents. The study identified immune-system genes linked to stronger or weaker protection after vaccination, helping explain why vaccine effectiveness varies between individuals.

ATN Era #2

ATN Era #3

ATN Era #4

ATN Era #5

ATN Era #2

ATN Era #3

ATN Era #4

ATN Era #5

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