Children's Health

Measles: Symptoms, Complications & Vaccine

Measles is one of the most contagious diseases known, and outbreaks are rising globally due to declining vaccination rates. It is not a trivial childhood illness — complications can be serious and even fatal.

Contagiousness
Among the most infectious diseases known (R0 12-18)
Vaccine
MMR — 2 doses, ~97% effective
Complication rate
1 in 15 develop serious complications
Fatality
1-2 per 1000 cases (higher in malnourished/young)

Symptoms and Timeline

DaySymptoms
Day 1-4 (prodrome)High fever, cough, runny nose, conjunctivitis (red eyes)
Day 2-3Koplik spots — small white spots inside the mouth (highly characteristic)
Day 3-5Red-brown rash starts on face, spreads down body over several days
Day 7-10Rash fades, cough may persist

Serious Complications

Why Measles Is Returning

Measles was declared eliminated in many countries after successful vaccination programmes. However, MMR uptake has fallen below the 95% threshold needed for herd immunity in many areas, driven by vaccine misinformation (including the debunked 1998 Wakefield study), leading to resurgent outbreaks.
Highly Contagious — Isolate and InformIf measles is suspected, contact your GP or NHS 111 by phone BEFORE attending in person — do not go directly to a waiting room, as measles spreads through the air and can infect vulnerable people (infants, pregnant women, immunocompromised) even briefly.
MMR Catch-UpIf you or your child missed any MMR doses, it's never too late to catch up — the vaccine is free on the NHS at any age and provides excellent protection even when given later than the routine schedule.
Does the MMR vaccine cause autism?
No. This claim originated from a single fraudulent, retracted study by Andrew Wakefield in 1998. Dozens of subsequent large studies involving millions of children worldwide have found no link between MMR and autism.
Can vaccinated people still get measles?
Rarely — the MMR vaccine is about 97% effective after 2 doses. Breakthrough infections are typically much milder than in unvaccinated people.
How long is someone with measles contagious?
From 4 days before the rash appears until 4 days after it appears — this long infectious window before symptoms are obvious is part of why measles spreads so effectively.
Medical Disclaimer: This page is for general education only and does not replace professional medical advice. Always consult a qualified healthcare provider.