The HVTN conducts all phases of clinical trials, bringing together experts from different sciences. Through this collaborative effort, the HVTN helps advance the HIV vaccinology field and, along the way, also helps advance the knowledge in fields as varied as social and behavioral sciences, statistics, and immunology. Our approach of integrated science give us the ability to look at the whole picture of HIV prevention, enabling us not only to fine-tune our study vaccines and recruiting methods, but also prepare for the day when an effective vaccine is found.

The questions we ask go far beyond, “Does this vaccine protect people from HIV/AIDS?” Here is a summary of how different sciences contribute to our overall mission.


Our clinical trials answer questions about vaccines and vaccination strategies. We use these answers in our search for an effective HIV vaccine.

The HVTN, with expert scientists from medical institutions across the globe alongside top clinicians, educators, and dedicated community representatives, is committed to conducting scientifically rigorous and ethical trials.


We apply the latest developments in immunology to standardize and expand approaches to the measurement and comparison of immune responses to vaccines.

HVTN Lab Center Assays for Clinical Trial Evaluation (click image to download pdf)

The HVTN maintains a vigorous program to facilitate the development of novel vaccine approaches. We are a leader in developing immunological assays to evaluate potential HIV vaccines. Our standardized assays and procedures provide rapid comparative data on experimental vaccines.

Our Laboratory Center has developed over 20 standardized assays that help us study immune responses in great detail and with significant accuracy. Descriptions of HVTN Laboratory Center assays can be found here.

Network researchers have developed several methods of sampling and processing samples from trial participants, allowing the HVTN to evaluate immune responses in different tissues and in blood. The differences in immune responses among different tissues and parts of the body can help design vaccines that target HIV at the places it is most likely to enter the body.

Conducting cutting edge analyses within the Network and collaboratively has resulted in significant changes and advances in HIV vaccines. These advances are described in publically available manuscripts.


We integrate biostatistics, bioinformatics, and computational biology to design and analyze clinical trials that provide definitive answers to questions about the potential of experimental vaccines.

HVTN statisticians develop statistical methods for clinical trial design and analysis. Their work includes creating a framework to understand immune responses, and developing new models for defining vaccine effects. Their achievements to date include:

  • Development of new trial design models (such as phase 2b trials) to efficiently evaluate vaccines
  • Development of new trial designs in response to developments in the field (for example, efficacy trials in the context of pre-exposure prophylaxis [PrEP] use)
  • Generation of sophisticated statistical methods for analyzing many complicated immunoassays
  • Methods for analyzing the safety, immune responses, and efficacy of study products in the context of social, behavioral, demographic, and genetic differences among participants

Behavorial Science

We incorporate new approaches from behavioral science to improve study volunteer recruitment, assess behavioral risks for HIV infection, and compare those risks with HIV infection rates or the efficacy of a vaccine.

The behavioral sciences examine how people act as individuals, and why they act in certain ways. The HVTN uses behavioral science methods to learn about behaviors affecting risk for becoming infected with HIV.

Accurate behavioral measures are important for many reasons, including:

  • They help us decide who can be in our clinical trials (some trials only enroll people whose risk of HIV infection is low; some trials look for people whose risk is high)
  • They help us look at what might affect our trial results besides the vaccine itself
  • They help us determine whether the participants in the study and control groups have risks that are about the same at the beginning of the study, and provide a measure of whether they remain comparable over time
  • They help us determine patterns of behavior change during a trial, and can indicate differences in risk, which might impact exposure to HIV
  • If a vaccine is efficacious, behavioral risk data can help us determine if different behaviors affect the efficacy of the vaccine
  • Behavioral data can help us estimate how much other biomedical interventions (such as PrEP) are used by the participants and in their segment of the population
  • They help us assess what risk behaviors should be taken into account when testing vaccine efficacy and correlates of protection

Social Science

We use social science concepts to look at human interactions, which helps us improve our engagement with communities and recruitment of study volunteers. We use social science models and theories to explore the many social factors that might impact trial design and implementation.

The social sciences look at the interactions of humans with each other, in large and small groups. The HVTN uses theoretical models and evidence from social science to look at factors that may have an effect on the efficacy of our study vaccines, and to improve our strategies for engaging communities and recruiting study volunteers.

Our social science work benefits our mission in many ways, including:

  • Understanding what impacts people’s perceptions of vaccine research and willingness to participate in HIV vaccine clinical trials
  • Identifying innovative community engagement approaches and outcome measures
  • Improving participation and retention rates
  • Improving adherence to study procedures and visits
  • Improving dissemination and acceptance of efficacious interventions