Everything You Need to Know About the Measles Vaccine

Measles is a highly contagious disease that can lead to serious health complications. The introduction of the Measles, Mumps, and Rubella (MMR) vaccine has been instrumental in controlling the spread of measles. However, despite its proven effectiveness, vaccination rates have been declining, leading to a resurgence of measles cases in Oklahoma, Texas and New Mexico.

History of Measles

One of the earliest written accounts of measles dates back to the 9th century when a Persian doctor, Rhazes, described the disease in his medical texts. In 1757, Scottish physician, Dr. Francis Home discovered that measles is caused by something infectious in the blood. By 1912, doctors in the United States had to report measles cases, and about 6,000 people died from it each year.

The measles vaccine was introduced in 1963 by John Enders and his team. Before the vaccine, nearly all children got measles by age 15, with millions infected yearly, leading to hundreds of deaths and thousands of hospitalizations.
In 1968, Maurice Hilleman developed an improved vaccine, which is still used today. This vaccine, often combined with mumps and rubella vaccines (MMR), greatly reduced measles cases and deaths.

The CDC aimed to eliminate measles by 1982. Although this goal wasn't met, cases dropped significantly. In 1989, a second dose of the MMR vaccine was recommended, further reducing cases. Measles was declared eliminated in the U.S. in 2000 due to high vaccination rates.

However, with declining measles vaccination rates, this disease has made an emergence. As of early 2025, the U.S. has already recorded over 378 confirmed measles cases, which is more than any single year since 2019. The new measles cases are being reported in Oklahoma, New Mexico and Texas.

How the Measles Vaccine Works

The MMR vaccine works by stimulating the immune system to recognize and fight the measles virus. It contains weakened versions of the measles, mumps, and rubella viruses, which prompt the body to produce antibodies. These antibodies remain in the body, ready to combat the actual viruses if exposed in the future. Two doses of the MMR vaccine provide about 97% protection against measles.

Children should receive two doses of the MMR (measles, mumps, rubella) vaccine. The first dose should be given at 12 to 15 months of age, and the second dose at 4 to 6 years of age. In outbreak settings, children can receive a dose at 6 months of age for protection. If they receive an early dose, they will still need two more doses according to the typical schedule. They can also get a second dose early as long as it's at least 28 days after initial dose, during outbreak settings.

Safety and Efficacy

The MMR vaccine is both safe and effective. Extensive research and monitoring have shown that serious side effects are extremely rare. Common side effects, such as mild fever or rash, are temporary and far outweighed by the benefits of vaccination. The Centers for Disease Control and Prevention (CDC) and other health organizations continue to endorse the MMR vaccine as a critical tool in preventing measles outbreaks.

Vaccination Rates and Herd Immunity

High vaccination rates are essential for achieving herd immunity, which protects those who cannot be vaccinated. Herd immunity occurs when most of the population is vaccinated, reducing virus spread. Some regions in Oklahoma are falling below necessary coverage levels, increasing the risk of outbreaks.

In Oklahoma, the statewide MMR vaccination rate for kindergarteners is about 87%, but only 17 counties exceed the 92% threshold needed for herd immunity. Nationally, around 90.8% of children are vaccinated against measles by 24 months, but overall coverage among kindergarteners is below the 95% target, with Oklahoma at 88.5%. Vaccination rates vary significantly by county, with some as low as 75%.

For More Information

For general vaccination information in Oklahoma. You can learn more at: Oklahoma State Department of Health.

The Oklahoma State Department of Health (OSDH) provides regular updates on measles cases and outbreaks on their website. This can help residents stay informed about the current situation. You can learn more at Oklahoma.gov/health/measles.

The OSDH conducts a Kindergarten Survey to provide information on vaccination rates. This data can give residents an idea of the vaccination coverage in their community.

Vaccination is the Best Prevention

Measles is still a big health problem, especially in places with low vaccination rates. The World Health Organization (WHO) says measles vaccines have saved millions of lives. However, outbreaks still happen, showing the need for ongoing vaccination. In 2023, about 107,500 people died from measles, mostly in countries with low vaccination coverage.

Staying informed about the measles vaccine and understanding its benefits is essential for protecting public health. By consulting with healthcare providers and ensuring vaccinations are up to date, we can work together to prevent measles outbreaks and safeguard our communities.