Mumps vaccine facts for kids

Mumps vaccines are special medicines called vaccines. They help stop people from getting mumps, a sickness caused by a virus. When most people in a community get vaccinated, it helps protect everyone. This is because the virus has fewer people to spread to.

If 90% of people are vaccinated, the vaccine is about 85% effective at preventing mumps. To get long-lasting protection, you usually need two doses. The first dose is often given when a child is between 12 and 18 months old. The second dose is usually given between two and six years of age.

What Are the Side Effects?

Most of the time, side effects from the mumps vaccine are mild. You might feel a little pain or see some swelling where the shot was given. A mild fever can also happen. Serious side effects are very rare. There isn't enough proof to say the vaccine causes serious problems like nerve issues.

Some people should not get the vaccine. This includes people who are pregnant or have a very weak immune system. However, there have been no reported problems for babies whose mothers got the vaccine while pregnant. Even though the vaccine is made using chicken cells, it's usually safe for people with egg allergies.

How Mumps Vaccines Are Used

Many countries around the world include the mumps vaccine in their regular immunization plans. It's often given as part of the MMR vaccine. This single shot protects against measles, mumps, and rubella vaccine. There's also an MMRV vaccine, which adds protection against chickenpox.

By 2005, 110 countries offered the mumps vaccine. In places where many people get vaccinated, the number of mumps cases has dropped by more than 90%. Over half a billion doses of one type of mumps vaccine have been given worldwide.

History of the Mumps Vaccine

In the middle of the 1900s, mumps in children wasn't seen as a big problem. But for adult men, mumps could cause painful swelling. During World War II (1939-1945), the United States government started researching mumps. The first experimental mumps vaccine came out in 1948. It used a killed virus, but it only worked for a short time.

Better Vaccines in the 1960s

Improved mumps vaccines became available in the 1960s. In 1963, a scientist named Maurice Hilleman from Merck & Co. took samples of the mumps virus from his daughter, Jeryl Lynn, who had mumps. He used these samples to create a new vaccine strain named after her: the Jeryl Lynn strain.

Scientists used new methods from vaccines for polio and measles. They grew the mumps virus in chicken eggs and chick embryo cells. This made the virus weaker and less able to cause sickness in humans. These weakened viruses are called attenuated viruses. They are also less harmful to human neurons (brain cells) than the wild mumps virus.

Hilleman's work led to the first truly effective mumps vaccine, called Mumpsvax. It was approved in 1967. It took four years to develop, which was a record at the time. Only the COVID-19 vaccine was developed faster, in less than a year.

Mumps Vaccine Becomes Routine

Getting vaccinated against mumps didn't become common until Mumpsvax was added to Merck's combined MMR vaccine. This vaccine protected against measles, mumps, and rubella all at once. The MMR vaccine was approved in 1971. By 1974, 40% of American children had received it.

In 1977, the U.S. Centers for Disease Control and Prevention (CDC) suggested that all children over 12 months old get the MMR vaccine. Later, in 1998, the CDC started recommending two doses of the MMR vaccine for better protection.

Types of Mumps Vaccines

The first mumps vaccine in the 1940s used a killed virus. But since the 1960s, mumps vaccines use a live, but weakened, virus. The mumps vaccine is on the World Health Organization's List of Essential Medicines. This means it's considered a very important medicine for basic health care.

Mumpsvax is the brand name for Merck's Jeryl Lynn strain vaccines. It's the mumps part of Merck's MMR vaccine and is the standard mumps vaccine in the United States. Mumpsvax is given as a shot under the skin. It uses a live virus that has been freeze-dried and then mixed with liquid before injection. Merck stopped making Mumpsvax as a stand-alone product in 2009.

Other Mumps Vaccine Strains

Scientists have developed other types of mumps vaccine strains:

• RIT 4385 is a newer strain that came from the Jeryl Lynn strain.
• Leningrad-3 strain was developed in Russia and has been used there since the 1950s.
• L-Zagreb strain is used in places like Croatia and India. It was made from the Leningrad-3 strain.
• Urabe strain was used in Japan and some European countries. However, it was linked to a slightly higher chance of meningitis (brain swelling), so many countries stopped using it.
• Rubini strain was mainly used in Switzerland. It was found to be less effective than other strains.

Storing Mumps Vaccines

Keeping vaccines cold is very important, especially in warmer countries. This is called the cold chain. Mumps vaccines are usually kept in a refrigerator. However, they can stay effective for about 65 days even at 23 degrees Celsius (73 degrees Fahrenheit).