The first COVID-19 vaccines are beginning to be introduced in countries. Before COVID-19 vaccines can be delivered:

The vaccines must be proven safe and effective in large (phase III) clinical trials. Some large clinical trials of COVID-19 vaccine candidates have reported encouraging preliminary results, and many other potential vaccines are being developed.
A series of independent reviews of the efficacy and safety evidence is required, including regulatory review and approval in the country where the vaccine is manufactured, before WHO considers a vaccine product for prequalification. Part of this process also involves the Global Advisory Committee on Vaccine Safety.
An external panel of experts convened by WHO, called SAGE, analyzes the results from clinical trials, along with evidence on the disease, age groups affected, risk factors for disease, and other information. The panel then recommends whether and how the vaccines should be used. Officials in individual countries decide whether to approve the vaccines for national use and develop policies for how to use the vaccines in their country based on the WHO recommendations.
The vaccines must be manufactured in large quantities, which is a major and unprecedented challenge – all the while continuing to produce all the other important life-saving vaccines already in use.
As a final step, all approved vaccines will require distribution through a complex logistical process, with rigorous stock management and temperature control.


WHO is working with partners around the world to accelerate every step of this process, while also ensuring the highest safety standards are met. More information is available here.