While no vaccine is 100% safe, overall, vaccines have an excellent safety record, according to CDC. And ongoing medical research and monitoring is making them safer and more effective.
Every vaccine goes through a lengthy approval process. Even after vaccines are licensed, they are carefully monitored.
Some people claim there is a link between vaccines and illnesses such as sudden infant death syndrome (SIDS), diabetes or autism. But no scientific evidence supports these claims, according to CDC.
While some vaccines have been found to cause rare, serious side effects (for example, the oral polio vaccine, which caused one case of paralysis for every 2.4 million doses and is no longer used in the United States), most side effects are mild to moderate and temporary.