US measles outbreak advisory urges British travellers to vaccinate before visiting Pennsylvania, South Carolina and Utah
British travellers to Pennsylvania, South Carolina or Utah are urged to be fully vaccinated against measles before departure. The advisory is in force now and targets visitors to the three US states with the highest case numbers.
In this story
At a glance
- What changes
- British visitors must confirm full MMR vaccination before traveling to Pennsylvania, South Carolina or Utah
- Timing
- Advisory is active immediately
- Who is affected
- British citizens planning trips to the three highlighted US states
The details
- Announced by
- Centers for Disease Control and Prevention (CDC)
- New rule
- The CDC now recommends that all travellers to the identified outbreak zones be fully vaccinated with two doses of MMR at least two weeks before departure.
Background of the outbreak
More than 5,100 measles cases have been recorded across 45 US states in 2026, the highest total since 1991. Pennsylvania (1,416 cases), South Carolina (759 cases) and Utah (606 cases) account for the largest concentrations. Over half of infections involve children and teenagers, and the hospitalisation rate is about 11 percent.
CDC travel health notice
The CDC issued a travel health notice urging all international visitors to the United States to be fully vaccinated against measles. The notice does not prohibit travel but stresses that two doses of the MMR vaccine provide 97 percent protection and should be administered at least two weeks before leaving.
- Two doses of MMR are recommended for optimal protection
- A single dose offers 93 percent effectiveness
Specific guidance for British travellers
The UK Foreign, Commonwealth & Development Office (FCDO) and the UK Health Security Agency (UKHSA) echo the CDC advice, asking British citizens to review their immunisation records before departure. Families with children, infants travelling internationally, and high‑risk adults such as healthcare workers are highlighted for extra caution.
- Infants 6‑11 months may need an early off‑schedule dose if travelling to hotspot areas
- Adults born after 1957 should have at least one documented MMR dose
What this means for travellers
Trip planning
- Travellers with existing bookings to Pennsylvania, South Carolina or Utah should verify MMR vaccination status before departure
- Those lacking two documented doses may need to postpone travel until vaccination is completed
Cost and documents
- No additional travel fees are introduced; only the cost of obtaining the MMR vaccine may apply
- Travelers should carry proof of vaccination or a doctor's note confirming immunity
What you need to do
- Check personal immunisation records at least two weeks before the planned trip
- If missing doses, arrange MMR vaccination promptly and obtain documentation
- Monitor CDC and UK health agency updates for any changes to the advisory
Who this affects
-
British families visiting Pennsylvania, South Carolina or Utah
These states have the highest measles caseloads in the US outbreak
What to do Ensure all family members have two documented MMR doses before travel
-
British business travellers to the three states
High‑risk environments increase exposure to the virus
What to do Confirm vaccination status and carry proof of immunity
-
British infants (6‑11 months) travelling to hotspot areas
Infants are vulnerable and may need an early MMR dose
What to do Consult a healthcare provider about an off‑schedule vaccine
-
British high‑risk adults (healthcare workers, students)
Occupational exposure raises infection risk
What to do Obtain two MMR doses at least 28 days apart if not already immune
Frequently asked questions
Do I need a measles vaccine to travel to the US?
Yes, the CDC advises all travellers to the outbreak zones in Pennsylvania, South Carolina and Utah to be fully vaccinated with two doses of MMR at least two weeks before departure.
How many doses of MMR are required for British travellers?
Two documented doses are recommended for full protection; a single dose offers lower, but still significant, effectiveness.
Can infants travel to the US without the full MMR schedule?
Infants aged 6‑11 months may receive an early off‑schedule MMR dose if travelling to an active outbreak area, but they must still complete the routine two‑dose series later.
What proof of vaccination should I carry?
Travellers should carry a vaccination record or a doctor’s note confirming receipt of the required MMR doses to show if requested by health authorities.
Will the advisory affect my existing flight bookings?
No flight changes are mandated, but travellers should verify their vaccination status before the trip and may need to reschedule if they are not fully vaccinated.
