Fact check: MMR vaccine is not more dangerous than measles and does not cause measles

Social media users have been sharing content online claiming the MMR (measles, mumps and rubella) vaccine is more dangerous than measles itself. This claim is false.

Reuters Fact Check. REUTERS

An example can be seen here and here .

One post’s description reads: “Most doctors are trained to deny vaccine failure, vaccine injury, and vaccine death. The MMR causes measles and other various side effects some of which are more serious than the measles that they try to scare the public with.”

According to the Centers for Disease Control and Prevention (CDC), measles causes symptoms such as high fever, cough, runny nose, watery eyes and rash. (here ) The CDC recommends the MMR vaccination to prevent measles, which the United States reported 1,282 cases of in 2019. ( and here )

The disease can be serious in all age groups, and children under 5 years, adults older than 20 years, pregnant women and those with compromised immune systems are more likely to develop complications, according to the CDC. Severe complications include pneumonia and encephalitis. Pregnant women who have measles may give birth prematurely or have a baby with low birth weight. More information on complications can be found here here .

The CDC says that before the measles vaccine, nearly everyone in the United States contracted the highly contagious virus and hundreds died each year. (here ) One dose of the vaccine is 93% effective and two doses are 97% effective at preventing contracting the virus if exposed. (here )

The CDC notes on its website: “Before the measles vaccination program started in 1963, an estimated 3 to 4 million people got measles each year in the United States, of which 500,000 were reported. Among reported cases, 400 to 500 died, 48,000 were hospitalized, and 1,000 developed encephalitis (brain swelling) from measles.” (here )

The U.S. Department of Health & Human Services explains potential side effects of the MMR vaccine on its website, which include a fever, mild rash and swollen glands. (here ) Less common side effects include pain or stiffness in the joints, potential seizures from a high fever and temporary low platelet count.

The department advises that as with any medicine, there is a very small chance that the vaccine can cause a serious reaction, but that receiving the measles vaccine is much safer than contracting measles. (here )

The Infectious Diseases Society of America explains on its website that the MMR vaccine does not cause measles. (here ) The vaccine is made from a weakened live virus which the immune system reacts to, causing some to have mild symptoms such as a fever or rash. This reaction is not the measles virus.

The Texas Children’s Hospital addresses myths about vaccines on its website. (here ) The hospital explains that with vaccines that contain weakened live viruses, such as the chickenpox or MMR vaccines, the patient might “develop a very mild illness that would be much less severe if the person did not receive the vaccination and contracted the disease.”

More information about the safety of the MMR vaccine can be found here .


False. The MMR vaccine that prevents the measles virus is not more dangerous than the virus itself and does not cause the virus.

This article was produced by the Reuters Fact Check team. Read more about our fact-checking work here  .