All the ingredients in a vaccine play an important role in ensuring a vaccine is safe and effective. These ingredients, as well as the vaccines themselves, have been thoroughly tested and are monitored to ensure they are safe.
This page answers the most frequently asked questions about COVID-19 vaccines and vaccine safety. If the information you are looking for is not here, check out our related links on the right-hand side of the page.
Vaccination is one of the most effective ways to prevent diseases. Over the past 50 years, essential vaccines against just 14 diseases have saved at least 154 million lives (1). During the same period, vaccination has contributed to 40% of the drop in infant deaths. Together with governments, vaccine manufacturers, scientists and medical experts, WHO's vaccine safety programme is constantly ...
The TAG-CO-VAC reconvened on 6-7 May 2025 to review the genetic and antigenic evolution of SARS-CoV-2; immune responses to SARS-CoV-2 infection and/or COVID-19 vaccination; the performance of currently approved vaccines against circulating SARS-CoV-2 variants; and the implications for COVID-19 vaccine antigen composition.
Vaccines are available to prevent more than 20 life-threatening diseases, helping people live longer, healthier lives. They reduce risks of getting a disease by working with your body’s natural defenses to build protection. When you get a vaccine, your immune system responds.
The World Health Organization (WHO) today announced recommendations for the viral composition of influenza (or “flu”) vaccines for the 2026-2027 northern hemisphere influenza season. The announcement was made following a 4-day consultation examining global influenza surveillance data.
The World Health Organization (WHO) has prequalified an additional novel oral polio vaccine type 2 (nOPV2), further strengthening the global supply of a vaccine at the heart of efforts to stop poliovirus type 2 outbreaks more sustainably and accelerate progress towards polio eradication.