The availability of a safe and effective vaccine for COVID-19 is well-recognized as an additional tool to contribute to the control of the pandemic. At the same time, the challenges and efforts needed to rapidly develop, evaluate and produce this at scale are enormous. It is vital that we evaluate as many vaccines as possible as we cannot predict how many will turn out to be viable. To increase the chances of success (given the high level of attrition during vaccine development), we must test all candidate vaccines until they fail. WHO is working to ensure that all of them have the chance of being tested at the initial stage of development. This is a major and extraordinary global research undertaking: WHO is facilitating collaboration and accelerated efforts on a scale not seen before; it is convening vital communications across the research community and beyond.

The 4 critical elements of WHO global R&D efforts in detail

1. Harnessing a broad global coalition to develop and evaluate candidate vaccines as quickly and safely as possible

WHO’s core function is to direct and coordinate international efforts through:

  • Global collaboration and cooperation;
  • Development of robust methods;
  • Working to accelerate progress and avoid duplication of research efforts;
  • Coordinating an unparalleled effort to rapidly and simultaneously assess many vaccines.

 WHO is facilitating interactions between scientists, developers and funders to support coordination, and/or provide common platforms for working together. It is combining the relative strengths of different stakeholders. It has used its global mandate to rapidly convene 300 scientists, developers and funders to increase the likelihood that one or more safe and effective vaccines will soon be available to all.  Activities are being delivered at extremely high speed with many steps executed simultaneously.

2. Mapping candidate vaccines and their progress across the world 

Over 120 vaccines have been proposed across the world and WHO is tracking details in a landscape exercise  on their type and progress.

There are currently six vaccines in clinical evaluation (with another about to start)*, and about 70 in pre-clinical evaluation.

WHO is fostering regular open dialogue between researchers and vaccine developers to expedite the exchange of scientific results, debate concerns and propose rapid and robust methods for vaccine evaluation.

3. Defining the desired characteristics of safe and effective vaccines to combat the pandemic  

To guide the efforts of vaccine developers, WHO has drawn up a Global Target Product Profile target product profiles(TPPs)  for COVID-19.

This document outlines the minimum and desired attributes of safe and effective vaccines. The TPPs cover two types of vaccines: vaccines for the long-term protection of people at higher risk of COVID-19 such as healthcare workers; and vaccines for use in response to outbreaks with rapid onset of immunity.

WHO has also coordinated expert consultations to identify the potential role of different animal models and laboratory assays to evaluate and screen candidate vaccines before their evaluation in humans. We are devising an unprecedented effort for rapid assessment of many candidates simultaneously before they are tested in humans.

4. Coordinating clinical trials across the world – giving humanity the best chance of safe and effective vaccines for all 

WHO is proposing to massively accelerate the evaluation of vaccines. Its expert group has designed a large international randomized controlled clinical trial to enable the simultaneous evaluation of the benefits and risks of different vaccines at sites with sufficiently high rates of the disease. This will ensure a faster turnaround of results.

The power of the vaccine Solidarity trial is its global ambition, and the potential to rapidly deploy and assess vaccines in areas with high transmission. The results for the efficacy of each vaccine are expected within three to six months and this evidence, combined with data on safety, will inform decisions about whether it can be used on a wider scale in those countries or regions where the vaccines are being tested.

To guide decisions on which vaccines to include in the clinical trials, WHO expert groups are also considering the following:

  • Key criteria to help prioritise which vaccines should go into Phase II and III Clinical trials;
  • A Phase 2b/3 Clinical Trial protocol that can be used by all vaccine developers to shape their trial, which will enable real-time evaluation of the benefits and risks of each promising candidate.

WHO expert groups are also considering:

  •  Key criteria to help prioritize which vaccines should go into Phase II and III clinical trials;
  • A Phase 2b/3 protocol  that can be used by all vaccine developers to shape their trial, which will enable real-time evaluation of the benefits and risks of each promising candidate vaccine.

Next steps

Once a safe and effective vaccine becomes available, it will be vital that it is accessible to everyone who needs it. WHO will continue to work to align R&D, fast-track regulatory approvals and manufacturing so that all populations in all countries can access a vaccine as early as possible.

The centre-piece of the world’s research response is a globally agreed scientific R&D Roadmap for COVID-19, which details steps for current and future work.

A full list of WHO R&D actions for COVID-19 are available here: