Comprehensive review of over 20,000 studies conclude vaccines are safe for children

Despite the controversy surrounding vaccines, a comprehensive analysis of more than 20,000 scientific titles and 67 papers on vaccine safety concluded that vaccines are safe for children and should be administered.

The review appears in the latest edition of the medical journal Pediatrics. The evidence strongly suggests that side effects from vaccines are incredibly rare and no ties were found between vaccines and the rising number of children with autism. This was in response to a small but vocal group of anti-vaccine activists, including actors Jenny McCarthy and Jim Carey.

The researchers, from the RAND Corporation, searched databases of scientific literature for vaccine-related studies, turning up 20 ,478 in total. This included studies of childhood vaccines - such as DTaP (diphtheria, tetanus and acellular pertussis), hepatitis A, hepatitis B, influenza, meningococcal, MMR (measles, mumps and rubella), and varicella - as well as adult vaccines such as flu shots.

"There is a lot of misinformation out there about vaccines," says co-author Margaret Maglione, also a researcher with Rand. "With the rise of the Internet and the decline of print journalism, anyone can put anything on the Internet."

Like all drugs, vaccines can cause serious side effects. But those complications are "extremely rare" and should be weighed against vaccination's enormous benefits, Maglione says.

Although they found no link between vaccines and autism or leukemia, they did find some very rare links between certain vaccines and children's health problems.

For example, the rotavirus vaccine is associated with an increased risk of intussusception, a serious disorder in which part of the intestine slides into an adjacent part of the intestine, causing blockage of the bowels.