How do countries decide whether to approve vaccines?

Many countries, regional health authorities, and global organizations (like the World Health Organization) have a detailed process for reviewing evidence to determine whether a vaccine is safe and effective and whether it should be approved for use in their jurisdiction.

This review process differs by country and regulatory authority. However, many regulatory authorities publish summaries of the evidence about how safe and effective a vaccine is based on phase 1, 2, and 3 clinical trial results . This evidence supports the decision to approve a vaccine. Some countries rely on the decisions of regional or global regulatory authorities and adopt their recommendations.

How are vaccines authorized for emergency use?

Many countries have a process for authorizing vaccines for emergency use to ensure timely access to essential medical resources, like vaccines against COVID-19 during the pandemic. The specific pathway for authorizing a vaccine for use is country-specific, though most countries follow international standards and evaluate vaccines based on phase 3 clinical trials to assess whether the vaccine meets appropriate standards for safety, efficacy, and quality. Even if a vaccine is given emergency use authorization, it must still undergo extensive review to ensure that it is safe and effective.

Emergency use authorizations are used in urgent situations typically when there are no approved and available alternative vaccines, and when the known and potential benefits of the vaccine in protecting people and keeping them healthy outweigh the known and potential side effects. Additionally, vaccines given emergency use authorizations, just like vaccines that are licensed or approved by other pathways, continue to be monitored as soon as vaccination campaigns begin to ensure that they remain safe and effective.

There are many approval pathways and these also differ by country and regulatory authority. On our site, vaccines listed as approved include vaccines that have been approved, authorized, licensed, given emergency use authorization, given emergency approval, or made available for use via any mechanism recognized in that country. Consult the official health authority in each country to learn more about the process.

Find out more about which vaccines are approved in your country .