How is the research and development process being accelerated without compromising safety?
WHO and its partners are committed to accelerating the development of COVID-19 vaccines while maintaining the highest standards on safety.
Vaccines go through various phases of development and testing – there are usually three phases to clinical trials, with the last one designed to assess the ability of the product to protect against disease, which is called efficacy. All phases assess safety. The last phase, phase III, are usually conducted in a large number of people, often 10’s of thousands. After that, the vaccine needs to go through a review by the national regulatory authority, who will decide if the vaccine is safe and effective enough to be put on the market, and a policy committee, who will decide how the vaccine should be used.
In the past, vaccines have been developed through a series of consecutive steps that can take many years. Now, given the urgent need for COVID-19 vaccines, unprecedented financial investments and scientific collaborations are changing how vaccines are developed. This means that some of the steps in the research and development process have been happening in parallel, while still maintaining strict clinical and safety standards. For example, some clinical trials are evaluating multiple vaccines at the same time. It is the scale of the financial and political commitments to the development of a vaccine that has allowed this accelerated development to take place. However, this does not make the studies any less rigorous.
The more vaccines in development the more opportunities there are for success.
Any longer-term safety assessment will be conducted through continued follow up of the clinical trial participants, as well as through specific studies and general pharmacovigilance of those being vaccinated in the roll out. This represents standard practise for all newly authorized vaccines.
More information about COVID-19 vaccine development is available here.
What are human challenge studies? What is WHO’s view on these studies?
In a regular vaccine study, one group of volunteers at risk for a disease is given an experimental vaccine, and another group is not; researchers monitor both groups over time and compare outcomes to see if the vaccine is safe and effective.
In a human challenge vaccine study, healthy volunteers are given an experimental vaccine, and then deliberately exposed to the organism causing the disease to see if the vaccine works. Some scientists believe that this approach could accelerate COVID-19 vaccine development, in part because it would require far fewer volunteers than a typical study.
However, there are important ethical considerations that must be addressed – particularly for a new disease like COVID-19, which we do not yet fully understand and are still learning how to treat; it may be difficult for the medical community and potential volunteers to properly estimate the potential risks of participating in a COVID-19 human challenge study. For more information, see this WHO publication on the ethics of COVID-19 human challenge studies.
Who should participate in clinical trials for COVID-19 vaccines?
Small (phase I) safety studies of COVID-19 vaccines should enroll healthy adult volunteers. Larger (phase II and III) studies should include volunteers that reflect the populations for whom the vaccines are intended. This means enrolling people from diverse geographic areas, racial and ethnic backgrounds, genders, and ages, as well as those with underlying health conditions that put them at higher risk for COVID-19. Including these groups in clinical trials is the only way to make sure that a vaccine will be safe and effective for everyone who needs it.
How do I volunteer for a COVID-19 vaccine trial?
Opportunities to volunteer for a COVID-19 vaccine trial vary from country to country. If you are interested in volunteering, check with local health officials or research institutions or email rdblueprint@who.int for more information about vaccine trials.
