Infectious Diseases

Measles (Rubeola): Symptoms, Risks, Vaccination, and Outbreaks

Measles is one of the most contagious viruses known. Learn symptoms, risks, vaccination guidance, and why outbreaks are resurging worldwide.

Updated: 3 min read

Measles (Rubeola)

Intro

Measles is a highly contagious viral illness that spreads through the air and can remain infectious for up to two hours after an infected person leaves a room.

Although preventable by vaccination, measles outbreaks are resurging worldwide due to immunity gaps, disrupted healthcare systems, and declining vaccination coverage.

Key Points

  • One of the most contagious viruses known
  • Airborne transmission with prolonged environmental survival
  • Serious complications including pneumonia and encephalitis
  • No antiviral cure — prevention is essential
  • Two-dose MMR vaccination provides ~97% protection

Risk Stratification

High risk:

  • Unvaccinated children
  • Infants under 12 months
  • Pregnant people
  • Immunocompromised individuals

Low risk:

  • Fully vaccinated adults

The Disease

  • Transmission: Airborne droplets and aerosols
  • Incubation period: 7–14 days
  • Early symptoms: Fever, cough, runny nose, red eyes
  • Classic signs: Koplik spots followed by a spreading red rash
  • Immune effects: Temporary immune suppression lasting months

Complications

  • Pneumonia (most common cause of death)
  • Encephalitis (~1 in 1,000 cases)
  • Vision and hearing loss
  • Subacute sclerosing panencephalitis (SSPE) — rare, delayed, and fatal

The Vaccine (MMR)

  • Licensed: 1963
  • Effectiveness: ~93% after one dose, ~97% after two doses
  • Safety: Excellent; serious adverse events are extremely rare
  • Population benefit: Protects infants and vulnerable individuals via herd immunity

Why Outbreaks Are Returning

  • Missed routine childhood vaccinations during COVID-19
  • Conflict and population displacement
  • Health system strain
  • Vaccine misinformation and hesitancy
  • International travel seeding new clusters

FAQ

Q: Can vaccinated people still get measles? A: Rarely. Breakthrough cases are usually mild and much less contagious.

Q: Is measles only a childhood illness? A: No. Adults can become severely ill, especially if unvaccinated.

Q: Is vitamin A useful in measles? A: Yes. In children, vitamin A supplementation reduces severity and mortality.

Further Reading

  • WHO — Measles fact sheets
  • CDC — Clinical guidance
  • ECDC — Global immunization data

Educational only; not a substitute for professional medical advice.