SPOKANE, Wash. -

It's been long debated whether childhood vaccines are actually safe for children. There's a growing number of anti-vaccine activists, including celebrities like Jim Carey and Jenny McCarthy. But a new study says children need to be vaccinated. 

The project screened more than 20,000 scientific titles and 6,700 papers on vaccine safety. They found that children should get vaccinated against preventable and potentially deadly diseases no matter what. 

The study was published in the medical journal "Pediatrics" and the evidence strongly suggests that side effects from vaccines are incredibly rare. 

The study found no ties between vaccines and the growing number of children with Autism. They also found no link between vaccines and childhood leukemia, as some other studies have suggested.

However, there was some evidence that the meningococcal vaccine can lead to a severe, whole-body allergic reaction in some children. 

While doctors say vaccines, like any medication, are not 100 percent risk free, they say serious reactions to vaccines are an anomily. 

Doctors say childhood vaccines are essential for good health. 

According to the study, millions of Americans live longer on average because of vaccines. Life expectancy has gone up in the United States by more than 30 years. 

The infant mortality rate has also decreased from 100 deaths per 1,000 children down to only 7.

Doctors say with all the data about childhood vaccinations, there's nothing to show an association with autism. 

Doctors urge the importance of childhood vaccinations, saying because of them many diseases that have plagued children for years have all but been eliminated.