The measles vaccine first became available in the United States in 1963

The first measles vaccine was licensed in the U.S. in March 1963. It was developed by John Enders and his team at Boston Children's Hospital, building on decades of research into the measles virus itself. The vaccine used a live but weakened form of the virus, called an attenuated vaccine.

Before 1963, measles was a common childhood disease that killed hundreds of Americans each year and left others with permanent brain damage, deafness, or blindness. The arrival of the vaccine changed the disease from inevitable to preventable. Within a few years, measles cases dropped sharply across the country.

Key Takeaways

  • The measles vaccine was licensed in the United States in March 1963 after being developed at Boston Children's Hospital.
  • The original vaccine was a live attenuated vaccine, meaning it contained a weakened form of the measles virus.
  • A second, improved measles vaccine was licensed in 1968 and became the standard version used in the U.S. for decades.
  • The measles vaccine has been part of routine childhood vaccination schedules since the 1960s, though the exact timing and number of doses has changed over time.

How the 1963 vaccine worked and why it was replaced

The original 1963 measles vaccine worked by exposing the immune system to a weakened virus, allowing the body to build immunity without causing the full disease. However, this first version sometimes caused a rash and fever in vaccinated children, and immunity could fade over time.

In 1968, a new measles vaccine was licensed that used a different strain of weakened virus. This improved vaccine caused fewer side effects and provided longer-lasting immunity. The 1968 version became the standard measles vaccine used in the United States and remained the main version for decades.

When measles vaccination became routine for all children

Measles vaccination was recommended for children starting in 1963, but it was not immediately mandatory everywhere. States and school districts gradually added measles to their required vaccination lists throughout the 1960s and 1970s. By the 1980s, measles vaccination was part of routine childhood care in all 50 states.

The current standard schedule calls for two doses of measles vaccine: the first dose at 12 to 15 months of age, and the second dose at 4 to 6 years old. This two-dose schedule has been in place since the 1980s and provides immunity to more than 99 percent of people who receive both doses.

The combined MMR vaccine and when it started

In 1971, the measles vaccine was combined with vaccines for mumps and rubella to create the MMR vaccine. This single shot protected against all three diseases instead of requiring separate injections. The MMR vaccine became the standard way measles protection was given to children and remains the most common form today.

The MMR vaccine uses the same weakened measles virus as the 1968 single-disease vaccine, so the measles protection itself did not change. What changed was convenience—one shot instead of three, and one appointment instead of multiple visits.

How measles rates changed after vaccination started

Before the vaccine, measles infected nearly all American children by age 15. In 1962, the year before the vaccine was licensed, there were more than 3 million measles cases reported in the U.S. By 1968, that number had dropped to about 22,000 cases. By the 1980s, measles was no longer a common childhood disease in America.

The United States declared measles eliminated in 2000, meaning the disease was no longer spreading continuously in the country. Measles cases that occurred after that year were almost always brought in from other countries where the disease was still common. This elimination remained in place until measles was reintroduced in recent years through unvaccinated populations.

Why the timing of the vaccine matters for understanding measles today

The 1963 start date explains why measles immunity patterns differ by age. Adults born before 1963 either had measles as children or were never vaccinated, depending on whether they caught the disease naturally. Adults born after 1963 were typically vaccinated as children and have vaccine-based immunity.

This history also matters for understanding measles outbreaks. When vaccination rates drop below a certain threshold in a community, measles can spread again—even though the vaccine has been available for 60 years. The disease itself has not changed, but the level of community immunity has.

Frequently Asked Questions

Did measles vaccination start at the same time everywhere in the U.S.?

The vaccine was licensed nationally in 1963, but states and school districts added it to their requirements at different times. Some states required it immediately; others took several years. By the 1980s, all states required measles vaccination for school entry.

Is the measles vaccine today the same as the 1963 version?

No. The 1963 vaccine was replaced by an improved version in 1968 that caused fewer side effects and provided better immunity. Today's MMR vaccine uses the 1968 strain of weakened virus combined with mumps and rubella protection.

Why did it take until 1963 to develop a measles vaccine?

Scientists had to first isolate and grow the measles virus in the laboratory, which took decades of work. Once they could grow it reliably, they could weaken it and test whether it was safe and effective. The entire process from virus discovery to licensed vaccine took roughly 30 years.

Could measles come back if vaccination rates keep dropping?

Yes. Measles is highly contagious and spreads quickly in unvaccinated populations. The disease has not disappeared from the world—it is still common in many countries. If vaccination rates fall too low in any community, measles can return and spread rapidly.