Anyone can report an adverse event to the VAERS. Patients, doctors, parents... if a person has had a vaccine and then gets sick sometime afterwards, there is always the option to report the event. That does not, however, mean that the vaccine caused the event.
There are many limitations to the VAERS, the biggest one being that there's no way to get around the fact that just because two events happen closely together in time -- for example a person getting a vaccine and then getting sick -- it doesn't mean that one of those events (getting the vaccine) caused the the other (getting sick). A large number of adverse events reported to VAERS probably have nothing to do with the vaccine they are linked to. It is therefore essential that scientific investigations of all serious events, particularly life threatening ones, be conducted before any conclusions about vaccine safety are drawn.
Other limits of the reporting system include:
- The reported events are usually unverified. They may not represent accurate diagnoses.
- Only the first report of an event is included. This may not be either the most up to date, or the most accurate, report.
- When, and if, data is verified, the database of adverse events my change.
- It is not always known what other factors may have led to the adverse event -- such as multiple vaccinations at the same time or another type of exposure.
- Often the prevalence of the reported events in the general (un-vaccinated) population is unknown -- making it difficult to tell whether or not the adverse event might have been expected to occur by chance
- Vaccine adverse event surveillance is passive as opposed to active. In other words people have to report events to the government, the government doesn't seek out the events. This means that some events almost certainly go unreported, which could lead to underestimating the magnitude of a potential problem.
In summary, although the VAERS is incredibly useful in monitoring vaccine safety, it is also incredibly fallible. Despite what some news reports suggest, events in the database, such as deaths, are not necessarily verified, and even if they are that is no guarantee that they are linked to the administration of a particular vaccine. People get sick every day. People die every day. Sometimes people get vaccines in the day, or week, before they would have gotten sick, or died, anyway. It takes careful scientific investigation to determine whether the events reported to VAERS are actually vaccine related, and oftentimes many of them are not.
Vaccines do have risks, that is undeniable, however those risks are often overstated by the news media and the public. Scientists and doctors have no desire to put healthy individuals in unnecessary danger.
The goal of vaccine use is to prevent health problems, not cause them. Although the VAERS isn't perfect, when used properly it is an important tool in monitoring vaccine safety.
Sources:
The CDC GARDASIL VAERS Report for 2008
The VAERS Information Page
