What to know about measles
Measles is one of the most contagious diseases of humans. Estimates suggest nine out of 10 nonimmune people exposed to measles will become infected. Measles is far more contagious than the flu, COVID-19, or even Ebola.
Before the introduction of measles vaccine in 1963, major epidemics occurred approximately every 2 to 3 years and it is estimated that 30 million cases of measles and more than 2 million deaths occurred globally each year, and that by the age of 15 years, more than 95% of individuals had been infected with measles virus.}
Measles is preventable and can be eliminated by vaccination. Before the introduction of measles vaccine in 1963, major epidemics occurred approximately every 2 to 3 years and it is estimated that 30 million cases of measles and more than 2 million deaths occurred globally each year, and that by the age of 15 years, more than 95% of individuals had been infected with measles virus.
Measles is preventable and can be eliminated by vaccination.
Vaccination is highly effective
Two doses of the current vaccine provide 97% protection — much higher than most other vaccines. Rarely, a person gets measles despite being fully vaccinated. When that happens, the disease tends to be milder and less likely to spread to others.
The safety profile of the measles vaccine is excellent. Common side effects include temporary soreness in the arm, low-grade fever, and muscle pain, as is true for most vaccinations.
A suggestion that measles or other vaccines cause autism has been convincingly discredited. However, this often-repeated misinformation has contributed to significant vaccine hesitancy and falling rates of vaccination.
Early diagnosis
It usually takes seven to 14 days for symptoms to show up once a person gets infected. Common early symptoms — fever, cough, runny nose — are similar to other viral infections such as colds or flu. A few days into the illness, painless, tiny white spots in the mouth (called Koplik spots) appear. But they’re easy to miss and are absent in many cases. A day or two later, a distinctive skin rash develops.
Measles can be serious and even fatal
Measles is not just another cold. A host of complications can develop, including brain inflammation (encephalitis), which can lead to seizures, hearing loss, or intellectual disability pneumonia eye inflammation (and occasionally, vision loss) poor pregnancy outcomes, such as miscarriage subacute sclerosing panencephalitis (SSPE), a rare and lethal disease of the brain that can develop years after the initial measles infection.
Complications are most common among children under age 5, adults over age 20, pregnant women, and people with an impaired immune system. Measles is fatal in up to three of every 1,000 cases.
Cost-effectiveness
Due to the availability of an inexpensive effective vaccine, measles immunization is one of the most cost-effective public health interventions in a wide range of development settings.
The bottom line
Infectious Diseases and Vaccine Experts warn that the number of cases (and possibly deaths) are likely to increase. And due to falling vaccination rates, outbreaks are bound to keep occurring.
The good news: measles outbreaks can be contained and the disease itself can be eliminated by vaccination, and during the past 50 years, has saved an estimated 94 million lives.
To limit the impact of measles outbreaks, WHO recommends surveillance for early detection, thorough assessment of the risk of spread and of severe disease outcomes, identification of immunity gaps, and planning rapid responses.
REFERENCES
- Minta AA, Ferrari M, Antoni S, et al. Progress Toward Measles Elimination — Worldwide, 2000–2023. MMWR Morb Mortal Wkly Rep 2024;73:1036–1042. DOI: http://dx.doi.org/10.15585/mmwr.mm7345a4
- Measles vaccines: WHO position paper – April 2017 – Weekly Epidemiological Record, 2017, vol. 92, 17 [full issue] – 28 April 2017
- World Health Organization. Measles and rubella strategic framework 2021–2030. Geneva, Switzerland: World Health Organization; 2020. https://www.who.int/publications/i/item/measles-and-rubella-strategic-framework-2021-2030
- Thompson KM and Odahowski CL (2016). Systematic review of health economic analyses of measles and rubella immunization interventions. Risk Analysis, 36(7), 1297–1314.
- Am J Respir Crit Care Med Vol. 211 P5-P6, 2025
- World Health Organization WHO | MMR and autism. MMR vaccines and autism. Published 2003. Accessed Feb 28, 2025.
- Centers for Disease Control and Prevention | Measles Cases and Outbreaks | CDC Measles Cases and Outbreaks | Measles (Rubeola) | CDC. Published 2025. Accessed Feb 28, 2025.
- American Academy of Pediatrics—Healthy Children.org https://www.healthychildren.org/English/safetyprevention/immunizations/Pages/How-to-Protect-YourChildren-During-A-Measles-Outbreak.aspx
