Vaccines and immunization: What is vaccination? The vaccine is therefore a safe and clever way to produce an immune response in the body, without causing illness Our immune systems are designed to remember Once exposed to one or more doses of a vaccine, we typically remain protected against a disease for years, decades or even a lifetime This is what makes vaccines so effective
COVID-19 vaccines - World Health Organization (WHO) Criteria for COVID-19 vaccine prioritization The proposed attributes and criteria provide considerations for the evaluation and prioritization of COVID-19 candidate vaccines to be considered for further development by WHO The target audience includes vaccine scientists, product developers, manufacturers, regulators and funding agencies
Vaccines and immunization - World Health Organization (WHO) Vaccination is a simple, safe, and effective way of protecting people against harmful diseases, before they come into contact with them It uses your body’s natural defences to build resistance to specific infections and makes your immune system stronger
How do vaccines work? - World Health Organization (WHO) This article is part of a series of explainers on vaccine development and distribution Learn more about vaccines – from how they work and how they’re made to ensuring safety and equitable access – in WHO’s Vaccines Explained series
A Brief History of Vaccination For centuries, humans have looked for ways to protect each other against deadly diseases From experiments and taking chances to a global vaccine roll-out in the midst of an unprecedented pandemic, immunization has a long history
Whats in a vaccine? - World Health Organization (WHO) Live-attenuated vaccine A live-attenuated vaccine uses a living but weakened version of the virus or one that’s very similar The measles, mumps and rubella (MMR) vaccine and the chickenpox and shingles vaccine are examples of this type of vaccine This approach uses similar technology to the inactivated vaccine and can be manufactured at scale
Coronavirus disease (COVID-19): Vaccines and vaccine safety 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
Statement on the antigen composition of COVID-19 vaccines 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
Know the facts - World Health Organization (WHO) Vaccination is a simple, safe, and effective way of protecting people against harmful diseases, before they come into contact with them It uses your body’s natural defences to build resistance to specific infections and makes your immune system stronger
Vaccines and immunization: Dengue TAK-003 is a live-attenuated vaccine containing weakened versions of dengue virus serotypes 1, 2, 3 and 4 developed by Takeda TAK-003 uses the DENV2 strain as the genomic backbone The vaccine schedule is a 2-dose series three months apart, given to specific age groups and in specific circumstances according to WHO recommendations