The Rise of Broadly Neutralizing Antibodies

Bill Snow founded AVAC and is the former Global HIV Vaccine Enterprise Executive Director.

Research on broadly neutralizing antibodies (bNAbs) is taking the field of HIV prevention science in new directions, with implications for new prevention interventions and vaccine development. There’s much to know and much to learn about these powerful instruments of the immune system.

Since 2016, more than 2,700 men in Brazil, Peru, Switzerland and the US, and 1,900 women in Southern Africa have begun to enroll in clinical trials looking at antibody-mediated prevention, or AMP (see Figure 1). A collaboration between the HIV Prevention Trials Network (HPTN) and HIV Vaccine Trials Network (HVTN) (both funded by the National Institutes of Health), the AMP studies test the safety and efficacy of the broadly neutralizing antibody (bNAb) VRC01 when it is given every 8 weeks to reduce the risk of HIV infection. But how did this approach come about, why is it important and what may happen next with bNAbs for HIV prevention?


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What’s an antibody?

Antibodies are Y-shaped proteins produced by B cells to clear infected cells and pathogens in the bloodstream. B cells are part of what is known as the adaptive immune system, which mounts defenses aimed at specific invaders—like a cold virus or chicken pox or HIV. The innate immune system also defends against invaders, but its defenses are not so finely tailored to a specific pathogen. When a virus encounters the right B cell, the B cell begins cloning itself and produces antibodies designed to battle that virus. These antibodies circulate throughout the body looking for the virus, and they evolve continuously, becoming ever more precise and numerous.

The Antibody Hierarchy

Here are some terms that will help you follow this ongoing story:

  • Antibody: Proteins produced by B cells as a major part of the adaptive human immune defense against specific invaders.
  • Binding antibody: An antibody that attaches to a virus but doesn’t necessarily render it ineffective; can be driven by the innate immune system.
  • Monoclonal antibody: A bioengineered antibody made in a manufacturing facility by copying (cloning) one original antibody—selected for its potency and other characteristics.
  • Neutralizing antibody: Antibody that disables virus.
  • Broadly neutralizing antibody: An antibody that neutralizes many different genetic variants of HIV.
  • Passive antibodies: A dose of monoclonal antibodies that are infused or injected, rather than made by one’s own immune system.

The Stories of HIV Vaccines in 2018—From science to stakeholder engagement

This four-pager explores stories about stakeholder engagement in the current suite of efficacy trials as well as stories around global support for vaccine research in the age of an expanded HIV prevention landscape.

Vaccines Efficacy Trials: A surge of activity

A picture of the status of vaccine trials since 2003: The four trials shown here represent an unprecedented number of late phase trials underway in vaccines research.

Prevention Research & Oral PrEP Rollout: The evolving context for HIV prevention research

Many of the current or planned prevention trials are taking place in countries where daily oral PrEP is available or will be soon. This infographic shows the status PrEP and the location of scheduled trials by country.

Vaccine and Antibody Trial Participant Recruitment, 2018

A global snapshot of total numbers of participants in trials by country.

HIV Vaccine Awareness Day: In May 2018, the story is…

HIV Vaccine Awareness Day (HVAD), May 18, is just a week away. Today, we’re bringing you AVAC’s annual HVAD Toolkit, a new advocacy resource—The Story Is…, and our HVAD webinar announcement!

AVAC’s HVAD 2018 webinar, to be held on Thursday, May 17, 9am ET, will tell the current story of HIV vaccine research from two perspectives. Dr. Sandhya Vasan of the Military HIV Research Program in Thailand will give her take on the world of HIV vaccine research since RV144: from where have we come, and where are we going? Mark Hubbard, a seasoned vaccine advocate and community representative for HIV research in Nashville, Tennessee will tell the story from a community and advocacy perspective: what are today’s current successes and challenges, and how are community members pushing the HIV vaccine agenda? Register now.

We’re especially excited in this year’s HVAD Toolkit to bring you a set of infographics that explain key aspects of vaccine research—trial participant and enrollment numbers, global funding, trials timelines, and more. We also have updated versions of old favorites you’ve come to expect each year, all available online at www.avac.org/hvad.

So, what is the story this year for HVAD? The story is the science, with an unprecedented level of vaccine and antibody clinical activity underway. But it’s not only the science—there are other important stories to tell as well, about global support for vaccine research in a time when there are many priorities in HIV prevention, and about stakeholder engagement in the current trial context. AVAC is publishing a special advocacy document, The Story Is…, which explores all this with an eye on primary prevention and the central role that research must play in it. Download it here.

As always, AVAC hopes these tools prove useful for HVAD events in your communities around the world. We know many of you are hard at work for HVAD, and we can’t wait to hear your stories, too.

Three Perspectives, Two Trials and One Big Goal

With more efficacy trials underway today than ever before in HIV prevention research, this episode of Px Pulse zooms in on two that have most recently launched: one of two trials testing a long-acting injectable antiretroviral called cabotegravir (HPTN 084), and the study of a “mosaic” vaccine developed by Janssen Pharmaceuticals (HVTN 705/HPX2008).

Three Perspectives on Two Big HIV Prevention Trials in Latest Px Pulse Podcast

The February episode of the Px Pulse podcast is up and brings you three perspectives on two recently launched major trials in HIV prevention: HPTN 084 testing a long-acting injectable antiretroviral called cabotegravir and HVTN 705/HPX 2008 testing a “mosaic” vaccine.

  • What opportunities stand out in an advocate’s eyes as these trials enroll?
  • What’s a mosaic vaccine?
  • What’s the status of ethical standards at trial sites?

Explore these issues and more in this episode of Px Pulse, AVAC’s podcast on HIV prevention research today.

You’ll hear from Malawi’s veteran advocate Maureen Luba, Zimbabwe-based bioethicist Paul Ndebele and leading scientist Dan Barouch.

In a hurry? Select among the podcast highlights.

And don’t forget to tell us what you think!

New Px Wire — 2018: Countdowns and counting what matters

The first issue of AVAC’s quarterly newsletter for 2018 is here! It’s designed to help you mark your calendars and make your advocacy plans for critical events in the next 12 months. These include:

  • The upcoming country deadlines for creating roadmaps to implement the priorities laid out by the UNAIDS’ Global Prevention Coalition. This work is supposed to jump-start primary prevention and bring down the rate of new diagnoses by 75 percent by 2020. Will it? Only if you get involved!
  • In the coming weeks, PEPFAR and many stakeholders will gather to develop targets, service delivery approaches and comprehensive plans for testing, prevention, treatment and virologic suppression in PEPFAR countries. It’s a key process for civil society to track. Find out how!
  • In 2019, the ECHO trial is expected to release its results on whether three different contraceptive methods impact women’s risk of HIV—but preparation for these trial results is starting now! Get involved!
  • Seven major efficacy trials of biomedical prevention tools are currently underway—read on to find out where, what and how to learn more.

This issue of Px Wire also includes a detailed infographic showing the status of oral PrEP rollout in the countries where trial sites are located. And don’t miss the infographic explaining the demographics of Africa’s “youth bulge” and its implications for the global response.

Find the full issue of Px Wire and the archive of past issues at www.avac.org/pxwire.

African Advocates Build Platforms and Networks to Push for HIV Prevention Access and Ethical Research Conduct in Africa

Morenike Oluwatoyin Folayan is an Associate Professor at Obafemi Awolowo University and Coordinator of the New HIV Vaccine and Microbicide Advocacy Society (NHVMAS) in Ife, Nigeria. This post first appeared in News Proof.

It was a beautiful sight to behold – the coming together of African advocates for HIV prevention access and conduct of biomedical HIV prevention research that respects the rights and welfare of participants. Acronyms like NHVMAS, AfNHI, VARG, AAVVi.net, APHA, WACIHealth were a delight to hear.

The New HIV Vaccine and Microbicide Advocacy Society (NHVMAS) was the oldest of the pack. It was formed by Advocates in Nigeria to push for the access of Nigerians to biomedical HIV prevention tools as soon as they were available way back in 2004. It is expanding its scope of work to West Africa and liasing with other networks to expand its work to Africa.

One of its chief liaison is WACIHealth. WACIHealth is focused on promoting increased domestic funding for health in Africa. It expanded its scope of work to include advocacy for HIV prevention commodity access, including promoting domestic investment for biomedical HIV prevention research, in 2011 just ahead of the Abuja+12 conference. Its partnership with NHVMAS led to the successful implementation of the biennial Biomedical HIV Prevention Forum since 2013. The forum serves as a platform for networking, sharing, providing updates and motivating for new action to promote access to HIV prevention tools and investment in ethical conduct of biomedical HIV prevention in Africa.

AfNHI is a birth product of the WACIHealth and NHVMAS with ample midwifery from AVAC. AfNHI envisons seeing Africa free of New HIV Infection. It is led by Africans for Africa and largely marries the vision of both WACIHealth and NHVMAS for the purpose of prevention new HIV infection in Africa. The network was launched during the 2017 Biomedical HIV Prevention pre-conference that held on the 3rd of December 2017 in Abidjan.

Also launched was the Vaccine Advocacy Resource Group (VARG). The Group is more global in outlook with members from beyond Africa. The lead of the Group – Tian Johnson – shared the goals and aspiration of the group at the meeting one of which was to be the voice of community advisory boards. The group is largely focused on promoting HIV vaccine research that respects the rights of study participants, and future end users. It tries to address the complex relationship between race, gender, rights and research. One of its most astounding work is the shift it accomplished with respect to PrEP access for all and by all study participants enrolled for HIV vaccine research in South Africa. This landmark shift in the context of designing and implementing HIV prevention research is historical and a huge success worthy of celebration – a proof that the VARG through its members – the VARGers – has the potential to make landmark changes in the way HIV prevention research is designed and implemented in Africa.

Also present at the meeting was Ntando Yola, a founding member of APHA – a group of HIV prevention advocates working in South Africa; and Prince Bahati, a member of AAVVi.net – a group of researchers and advocates who are set to shape the science of HIV vaccine research in Africa.

While it is so heartening to see the evolution of these groups on the continent the hosts the highest number of HIV prevention research, it was clear that more work needs to be done to breed new and many young advocates on the continent. You find the same set of people belonging to the groups. This comes with its challenges – how novel and distinct can the concepts and ideas of these groups be? How do they deal with conflicts of interest? How do the organisations handle the financial resources from funders?

The AVAC Fellowship and PxROAR Africa programmes and the NHVMAS LeNNiB Champion project may be one of the many ways to address this time-limited challenge. Let’s look forward optimistically to what these networks, platforms, organisations, programmes and project is set to do for HIV epidemic on the sub-Saharan continent.