The Adolescent Medicine Trials Network

The Adolescent Medicine Trials Network

ATN History

Since 2001, the ATN has been at the forefront of discoveries, innovation, and impact in HIV prevention and care.

Behind each of our 100+ research studies is a question, a challenge, and a partnership among researchers, healthcare providers, and young people working together to keep youth healthy.

This story belongs to the 30,000+ young people who made our research possible—youth experiences and voices helped drive over 25 years of progress in HIV prevention and treatment. Explore the ATN’s bold ideas and lasting impact.

The Highlights

Swipe through to explore key ATN studies and historic events since 2001 that have shaped HIV & STI prevention and treatment for adolescents and young adults.

How to Look at Our Story

Dark pink: ATN Funding Cycles Different eras of the ATN’s journey. Purple: ATN Research Studies Projects that help answer important questions about adolescent sexual health. Green: HIV & STI Milestones Major changes in prevention and care for HIV and STIs. Blue: Impact of the ATN Highlighting how the ATN’s research helped shape HIV and STI milestones.
2001-2006 ATN Era #1 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.
2001-2006 ATN 016: Connect to Protect (C2P) ATN 016 launched C2P, which included several studies spanning two ATN funding cycles. It focused on creating lasting change in environments and systems, rather than changing individual behavior. C2P brought together coalitions of youth, researchers, healthcare providers, community orgs, and policymakers to identify and address community barriers making it harder for youth to stay healthy.
2006-2011 ATN Era #2 During the ATN’s second funding cycle, our research studies focused on addressing barriers like stigma, housing, and limited access to healthcare services.
2006-2011 ATN 041: Connect to Protect (C2P) This phase of C2P built on earlier partnerships by putting HIV prevention plans into action. Communities worked together to improve local programs, services, and resources to make it easier for youth to get the information, testing, and support they needed to stay healthy.
2011-2016 ATN Era #3 The ATN expanded its research to focus on helping young people access more HIV prevention tools. The network generated key evidence that supported the use of PrEP and other HIV prevention strategies for adolescents and young adults.
2013-2016 ATN 113: PrEPare One of the first studies to show that PrEP, an HIV prevention medication, is safe and acceptable for teens ages 15-17. It paved the way for PrEP to become available to adolescents. It also showed teens may need extra support, reminders, and youth-friendly care to stay on PrEP consistently and get the most protection.
2015-2016 ATN 132: Epic Allies Utilized gaming mechanics and social networking to support HIV care, antiretroviral therapy, and adherence, demonstrating the value and importance of mobile health interventions for youth.
2016-2022 ATN Era #4 The ATN restructured its research into coordinated multi-project hubs: iTech, Scale It Up, and CARES. Restructuring emphasized technology-enabled interventions, youth-centered design, and systems-level approaches to HIV prevention and care.
2017-2022 ATN 150: Minor Consent & Confidential Care Addressed legal and ethical barriers that historically prevented many young people from safely accessing sexual health services.
2017-2020 ATN 151: Work-to-Prevent Linked employment and economic stability to HIV prevention outcomes, expanding HIV prevention beyond individual behavior to include structural and socioeconomic conditions.
2018 FDA Greenlights PrEP as HIV Prevention for Teens Before the approval of a daily HIV prevention pill called Truvada for adolescents aged 13+, teens didn't have access to HIV prevention medication. Having oral PrEP available to youth, who account for 1 out of every 5 new HIV diagnoses in the U.S., was a massive win for keeping youth healthy. This major approval happened because our study called ATN 113: PrEPare showed that the medication worked for youth, too.
2018-2021 ATN 144: SMART SMART reframed adherence challenges by identifying opportunities for additional support, shifting from the perspectives of adherence being attributed to personal failure. This signaled a structural shift in responsibility toward responsive care systems.
2018-2021 ATN 146: Tailored Motivational Interviewing Trained healthcare providers in Tailored Motivational Interviewing, and found that when clinic conversations shift from giving medical orders to collaborative conversations, young people living with HIV are better able to build their own internal motivation to manage their health and stay engaged in HIV treatment.
2018-2020 ATN 152: TERA Showed that real-time support—like text messages, virtual coaching, and smart medication monitoring—can help young people living with HIV take their medication more consistently. and stay engaged in their HIV care.
2018-2020 ATN 154: Cascade Monitoring Tracked how young people moved through different steps of HIV care—from getting connected to a clinic to staying in treatment and reaching an undetectable viral load. By identifying where youth were doing well and where they were more likely to fall out of care, this study’s findings hope to help clinics and researchers develop better ways to support the long term health of youth living with HIV.
2019 Undetectable = Untransmittable Endorsed by CDC Research from the HIV Prevention Trials Network (HPTN) 052 study and the PARTNER studies followed more than 2,000 serodifferent couples (where one partner has HIV and the other does not) and found zero cases of HIV transmission when the partner living with HIV maintained an undetectable viral load through treatment. U=U dispels outdated, fear-based stigma and myths about HIV transmission, proving people living with HIV who are on effective treatment can date, hook up, love, live full sexual lives, and have children with absolutely zero fear of passing HIV on to someone else.
2019-2022 ATN 155: Planning4PrEP Developed and tested ways to offer PrEP through family planning and reproductive health clinics. The goal was to bring HIV prevention into healthcare settings that many young women already visit, helping more adolescent and young women access PrEP.
2019-2022 ATN 159: ePrEP Demonstrated that a virtual PrEP program could be delivered to young men in rural communities, allowing them to receive HIV prevention care, complete testing, and manage PrEP using telelhealth and at-home test kits. This study helped lay the groundwork for the expanded use of virtual healthcare approaches that became much more common during and after the COVID-19 pandemic.
2020-2022 ATN 156: We Test Showed that couples-based HIV testing and communication support helped young same-sex male couples talk more openly about HIV prevention, sexual health, and PrEP, providing evidence that relationship-focused approaches may be a useful way to support HIV prevention among youth.
2022-2030 ATN Era #5 Our current cycle focuses on helping more youth learn their HIV status, prevent new HIV transmission, connect to HIV care, stay on treatment, and seeks to address the ongoing effects of COVID-19 on health.
2022 Long-Acting HIV Medication Approved for Adolescents The FDA approved Cabenuva (cabotegravir/rilpivirine) in 2021, making it the first long-acting injectable treatment for adults living with HIV. In 2022, it was approved for teens aged 12+. Do the math: with an injection every 2 months, treatment drops to just 6 times a year instead of swallowing a pill 365 days a year. This completely changes the vibe of managing HIV, giving youth (and adults) the freedom to live thier lives without worrying about daily phone alarms or carrying medication.
2024 DoxyPEP Guidelines Released by CDC Taking DoxyPEP (doxycycline post-exposure prophylaxis) after potential exposure is a total game-changer for protecting sexual health—think of DoxyPEP kind of like a morning-after pill, but for preventing bacterial sexually transmitted infections. DoxyPEP significantly reduces men's chances of getting syphilis, chlamydia, and gonorrhea by 50-80%. Right now, the CDC’s guidelines are for certain populations like gay and bisexual men. However, more research is needed before more populations, like women, can have access to DoxyPEP.
2024-2025 ATN 168: HAPPY The HIV and Pregnancy Prevention for Youth (HAPPY) study explored young people's interest in a long-acting injectable medication that could prevent both HIV and pregnancy. By learning what features youth value in prevention options, researchers hope to help shape future tools that are easier for young people to access and use. Findings coming soon!
2024 Twice-A-Year PrEP Injection Changes HIV Prevention In 2025, the FDA approved Yeztugo (lenacapavir), the first long-acting injection for HIV prevention. It requires only two doses per year. Remembering to take a pill consistently is a lot of pressure, and missing doses makes oral PrEP less effective, so this provides a crucial alternative to daily oral PrEP that can increase adherence.

How to Look at Our Story

ATN Funding Cycles
Different eras of the ATN’s journey.

ATN Research Studies
Projects that help answer important questions about adolescent sexual health.

HIV and STI Milestones
Major changes in prevention and care for HIV and STIs.

Impact of the ATN
Highlighting how the ATN’s research helped shape HIV and STI milestones.

2001-2006 ATN Era #1 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.
2001-2006 ATN 016: Connect to Protect (C2P) ATN 016 launched C2P, which included several studies spanning two ATN funding cycles. It focused on creating lasting change in environments and systems, rather than changing individual behavior. C2P brought together coalitions of youth, researchers, healthcare providers, community orgs, and policymakers to identify and address community barriers making it harder for youth to stay healthy.
2006-2011 ATN Era #2 During the ATN’s second funding cycle, our research studies focused on addressing barriers like stigma, housing, and limited access to healthcare services.
2006-2011 ATN 041: Connect to Protect (C2P) This phase of C2P built on earlier partnerships by putting HIV prevention plans into action. Communities worked together to improve local programs, services, and resources to make it easier for youth to get the information, testing, and support they needed to stay healthy.
2011-2016 ATN Era #3 The ATN expanded its research to focus on helping young people access more HIV prevention tools. The network generated key evidence that supported the use of PrEP and other HIV prevention strategies for adolescents and young adults.
2013-2016 ATN 113: PrEPare One of the first studies to show that PrEP, an HIV prevention medication, is safe and acceptable for teens ages 15-17. It paved the way for PrEP to become available to adolescents. It also showed teens may need extra support, reminders, and youth-friendly care to stay on PrEP consistently and get the most protection.
2015-2016 ATN 132: Epic Allies Utilized gaming mechanics and social networking to support HIV care, antiretroviral therapy, and adherence, demonstrating the value and importance of mobile health interventions for youth.
2016-2022 ATN Era #4 The ATN restructured its research into coordinated multi-project hubs: iTech, Scale It Up, and CARES. Restructuring emphasized technology-enabled interventions, youth-centered design, and systems-level approaches to HIV prevention and care.
2017-2022 ATN 150: Minor Consent & Confidential Care Addressed legal and ethical barriers that historically prevented many young people from safely accessing sexual health services.
2017-2020 ATN 151: Work-to-Prevent Linked employment and economic stability to HIV prevention outcomes, expanding HIV prevention beyond individual behavior to include structural and socioeconomic conditions.
2018 FDA Greenlights PrEP as HIV Prevention for Teens Before the approval of a daily HIV prevention pill called Truvada for adolescents aged 13+, teens didn't have access to HIV prevention medication. Having oral PrEP available to youth, who account for 1 out of every 5 new HIV diagnoses in the U.S., was a massive win for keeping youth healthy. This major approval happened because our study called ATN 113: PrEPare showed that the medication worked for youth, too.
2018-2021 ATN 144: SMART SMART reframed adherence challenges by identifying opportunities for additional support, shifting from the perspectives of adherence being attributed to personal failure. This signaled a structural shift in responsibility toward responsive care systems.
2018-2021 ATN 146: Tailored Motivational Interviewing Trained healthcare providers in Tailored Motivational Interviewing, and found that when clinic conversations shift from giving medical orders to collaborative conversations, young people living with HIV are better able to build their own internal motivation to manage their health and stay engaged in HIV treatment.
2018-2020 ATN 152: TERA Showed that real-time support—like text messages, virtual coaching, and smart medication monitoring—can help young people living with HIV take their medication more consistently. and stay engaged in their HIV care.
2018-2020 ATN 154: Cascade Monitoring Tracked how young people moved through different steps of HIV care—from getting connected to a clinic to staying in treatment and reaching an undetectable viral load. By identifying where youth were doing well and where they were more likely to fall out of care, this study’s findings hope to help clinics and researchers develop better ways to support the long term health of youth living with HIV.
2019 Undetectable = Untransmittable Endorsed by CDC Research from the HIV Prevention Trials Network (HPTN) 052 study and the PARTNER studies followed more than 2,000 serodifferent couples (where one partner has HIV and the other does not) and found zero cases of HIV transmission when the partner living with HIV maintained an undetectable viral load through treatment. U=U dispels outdated, fear-based stigma and myths about HIV transmission, proving people living with HIV who are on effective treatment can date, hook up, love, live full sexual lives, and have children with absolutely zero fear of passing HIV on to someone else.
2019-2022 ATN 155: Planning4PrEP Developed and tested ways to offer PrEP through family planning and reproductive health clinics. The goal was to bring HIV prevention into healthcare settings that many young women already visit, helping more adolescent and young women access PrEP.
2019-2022 ATN 159: ePrEP Demonstrated that a virtual PrEP program could be delivered to young men in rural communities, allowing them to receive HIV prevention care, complete testing, and manage PrEP using telelhealth and at-home test kits. This study helped lay the groundwork for the expanded use of virtual healthcare approaches that became much more common during and after the COVID-19 pandemic.
2020-2022 ATN 156: We Test Showed that couples-based HIV testing and communication support helped young same-sex male couples talk more openly about HIV prevention, sexual health, and PrEP, providing evidence that relationship-focused approaches may be a useful way to support HIV prevention among youth.
2022-2030 ATN Era #5 Our current cycle focuses on helping more youth learn their HIV status, prevent new HIV transmission, connect to HIV care, stay on treatment, and seeks to address the ongoing effects of COVID-19 on health.
2022 Long-Acting HIV Medication Approved for Adolescents The FDA approved Cabenuva (cabotegravir/rilpivirine) in 2021, making it the first long-acting injectable treatment for adults living with HIV. In 2022, it was approved for teens aged 12+. Do the math: with an injection every 2 months, treatment drops to just 6 times a year instead of swallowing a pill 365 days a year. This completely changes the vibe of managing HIV, giving youth (and adults) the freedom to live thier lives without worrying about daily phone alarms or carrying medication.
Taking DoxyPEP (doxycycline post-exposure prophylaxis) after potential exposure is a total game-changer for protecting sexual health—think of DoxyPEP kind of like a morning-after pill, but for preventing bacterial sexually transmitted infections. DoxyPEP significantly reduces men's chances of getting syphilis, chlamydia, and gonorrhea by 50-80%. Right now, the CDC’s guidelines are for certain populations like gay and bisexual men. However, more research is needed before more populations, like women, can have access to DoxyPEP.
2024-2025 ATN 168: HAPPY The HIV and Pregnancy Prevention for Youth (HAPPY) study explored young people's interest in a long-acting injectable medication that could prevent both HIV and pregnancy. By learning what features youth value in prevention options, researchers hope to help shape future tools that are easier for young people to access and use. Findings coming soon!
2024 Twice-A-Year PrEP Injection Changes HIV Prevention In 2025, the FDA approved Yeztugo (lenacapavir), the first long-acting injection for HIV prevention. It requires only two doses per year. Remembering to take a pill consistently is a lot of pressure, and missing doses makes oral PrEP less effective, so this provides a crucial alternative to daily oral PrEP that can increase adherence.

The Full Story

Dive deep into all ATN studies alongside key HIV and STI milestones that have transformed research, policy, and public health since 2001.

The National Institutes of Health (NIH) funds the ATN in cycles that last for about 5-7 years. In each cycle, NIH determines the structure of the network and areas of focus for research studies that will occur in the cycle.

ATN Era #1

2001-2006

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.

Explore ATN Era #1

Jump to:

1996
2001
2003
2004
2005

ATN Era #2

2006-2011

The ATN’s research studies during this time focused on addressing barriers like stigma, housing, and limited access to healthcare services.

Explore ATN Era #2

Jump to:

2006
2007
2008
2009
2010

ATN Era #3

2011-2016

During this era, the ATN expanded its research to focus on helping youth access more HIV prevention tools.

The network generated key evidence that supported the use of PrEP and other HIV prevention strategies for adolescents and young adults.

Jump to:

2011
2012
2013
2015
2016

ATN Era #4

2016-2022

The ATN restructured into multi-project hubs (iTech, Scale It Up, & CARES) that created and tested digital health interventions, youth-centered design, and systems-level approaches to HIV prevention and care.

Jump to:

2016
2017
2018
2019
2020
2021

ATN Era #5

2022-2030

Our current cycle focuses on helping more youth learn their HIV status, prevent new HIV transmission, connect to HIV care, stay on treatment, and seeks to address the ongoing effects of COVID-19 on health.

Jump to:

2022
2024
2025