How is vaccine safety monitored? 

As something that is administered to millions of children, vaccinations are one of the more closely monitored programs in the medical field.  At every step of development, the safety of the vaccine is considered.  In order to make it to the market, a vaccine must fulfill several criteria. This does not mean that every vaccine is 100% safe.  No medical intervention is entirely safe.  The goal is for the vaccine to be safer and prevent more adverse outcomes then would occur without it.  It is up to vigilant parents and health car providers to keep on the look out for possible safety concerns so that the population can be as safe as possible.

Criteria for being a recommended vaccination:

• The disease was sufficiently common to be a burden to society.

• The disease causes significant illness and/or death.

• A vaccine is available.

• The vaccine is effective in preventing the most serious effects of the disease.

• The vaccine is effective in the age group that is most susceptible to the effects of the disease.

• The vaccine has far fewer side effects than the disease it is preventing.

• Widespread administration of the vaccine is cost effective. 

 Ongoing safety monitoring:               

Even after a vaccination has been released and is being used with the general population, the government and the manufacturer keep track of adverse events that may be related to the vaccination. The Vaccine Adverse Event Reporting System (VAERS) is a national database that collects reports of adverse events that occur after vaccines are administered. Any adverse effect following a vaccination can be submitted.  Forms can be submitted by physicians, manufacturers, parents or patients.  Physicians are required to submit forms for many serious events.  Not every adverse affect reported to VAERS is caused by the vaccination.  It is simply temporally related.   The purpose of this monitoring is to try and detect trends and ultimately determine causality.  The data is analyzed regularly so that trends may be recognized as early as possible and investigated.  If a vaccination is found to be causing a serious adverse effect, the vaccine may be removed form the market. 

Links:

VAERS - The Vaccine Adverse Event Reporting System

The CDC explains the Vaccine Product Approval Process:  http://www.hhs.gov/nvpo/factsheets/fs_tableII_doc2.htm