Due to the success of immunization, some diseases are no longer perceived as a threat. Certain groups have even questioned the utility of vaccination in spite of its proven success in controlling disease. In recent years, a number of websites providing unbalanced, misleading and alarming vaccine safety information have been established, which can lead to undue fears, particularly among parents and patients. Acknowledging the above-mentioned issues and urged by governments, key non-governmental organizations and the United Nations Children's Fund (UNICEF), WHO initiated, in 2003, the Vaccine Safety Net Project (VSN).

The mission of the Vaccine Safety Net is to help internet users find reliable vaccine safety information tailored to their needs.

A key player in the Project is the Global Advisory Committee on Vaccine Safety (GACVS), established by WHO in 1999, to respond promptly, efficiently, and with scientific rigor to vaccine safety issues of potential global importance. 

At the outset of the Project, GACVS developed three categories of criteria for good information practices - regarding credibility, content and accessibility/design to which sites providing information on vaccine safety should adhere. WHO evaluates websites for their adherence to these criteria.

a. Evaluation of new websites

WHO is pleased to evaluate new candidates for inclusion in the VSN on a rolling basis. Please note that not all websites are eligible to join the VSN. For more information please look to the eligibility criteria.

The VSN evaluation process unfolds in the following manner:

- If you feel that your site meets the GACVS criteria outlined above, kindly download the VSN application form, complete it, and send it to  to pvsupport@who.int

- WHO will then conduct a preliminary assessment of your website. If your website meets the screening criteria then WHO will conduct a formal assessment.

- During the formal assessment, your website will be evaluated against the revised criteria for good information practices by a team comprised of the VSN coordinator and one or more external consultants.

- The evaluation team will send you feedback regarding any areas that require clarification or improvements in order to meet the GACVS criteria as well as a set of recommendations to assist you in meeting these criteria. When applicable, the WHO evaluation team will provide examples illustrating different ways that VSN members have addressed each recommendation.

- Once the identified issues have been addressed to the satisfaction of the evaluators, WHO will add your web site to the list of VSN members.

b. Re-evaluation of VSN member websites

Re-evaluations are conducted every one or two years, depending on the type of institution the website belongs to. The VSN evaluation process unfolds in the following manner:

- The team will re-evaluate your website against the good information practices criteria and send you feedback regarding any areas that require clarification or improvements to meet the GACVS criteria, as well as a set of recommendations to assist you in meeting these criteria. When applicable, the WHO evaluation team will provide examples illustrating different ways that VSN members have addressed each recommendation.

- When sites are considered by evaluators to satisfactorily meet the good information practices criteria, the date of finalization of the reevaluation is indicated at the bottom of the site description.

Please visit the VSN portal to access numerous and useful resources from VSN members’ and make them available to the public, health practitioners and policymakers.