Infectious Diseases
Measles (Rubeola): The Disease and the Vaccine
2025-10-05
Measles (Rubeola): The Disease and the Vaccine
Intro
Measles is one of the most contagious viruses known — capable of infecting up to 9 out of 10 unvaccinated contacts after exposure.
It spreads through the air and can remain suspended for up to two hours.
The measles vaccine (MMR: measles, mumps, rubella) is safe, highly effective, and essential to public health.
Outbreaks return wherever coverage drops.
Key Points
- Contagious: One case can infect most unvaccinated contacts nearby.
- Vaccine effectiveness: ~97% after two doses.
- Herd protection: ~95% coverage required.
- Impact: Over 23 million deaths prevented since 2000.
- Safety: Decades of data show no link to autism.
The Disease
- Transmission: Airborne droplets/aerosols; survives up to 2 hours.
- Symptoms: Fever, cough, runny nose, red eyes, Koplik spots, spreading rash.
- Complications: Pneumonia, encephalitis (~1 in 1,000), rare fatal SSPE.
- At risk: Infants, pregnant people, immunocompromised.
The Vaccine
- History: Licensed 1963; improved formulations soon after.
- Formulations: MMR or MMRV.
- Effectiveness: One dose ≈ 93%; two ≈ 97%.
- Safety: Mild reactions common; serious events exceedingly rare.
- Myths: Autism claim was fraudulent and retracted.
Recent Outbreaks
The 2025 U.S. outbreak has surpassed 1,500 cases across > 20 states — the highest since 2019.
Clusters arise where vaccination rates fell below 95%.
International travel continues to seed cases.
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