South Carolina: Largest US Measles
Outbreak in Decades (646
Cases)
South Carolina reports 646 confirmed measles cases as
of January 20, 2026—212 new infections in one week alone, making it the
largest US outbreak in decades. Centered in Spartanburg/Greenville
counties, the epidemic originated October 2025 in schools with high
unvaccinated populations.
Outbreak Statistics & Vaccination Breakdown
- 563
cases unvaccinated (87%)
- 12
cases partially vaccinated (1 dose MMR)
- 13
cases fully vaccinated (breakthrough infections)
- 58
cases unknown status
- 155
children under 5 years; 419 ages 5-17
- 538
quarantined, 33 isolated
6 schools quarantined; Clemson University (34 students),
Anderson University (50 students) locked down after campus exposures.
Expert Warnings: "Exponential Growth Phase"
Dr. William Moss (Johns Hopkins): "88 new
cases since Friday shows this outbreak is far from over... pockets of
susceptible individuals drive spread".
SC DPH Director Dr. Barbara Hancock: "Northwest
region overwhelmed. University spread signals community transmission".
Virginia: 2nd Child Case Sparks Interstate Spread Fears
Virginia confirms its 2nd measles case in a child
following international travel exposure linked to South Carolina visitors. The
family visited King/Snohomish Counties, Washington over holidays,
sparking a 3-case Washington cluster (unvaccinated siblings aged 23
months-9 years).
Kittitas County, WA: Central Washington University student
tests positive—first local case in 18 years.
Virginia Health Response
- Public
exposure warnings issued for airport, mall, restaurants
- Contact
tracing identifies 200+ potential exposures
- MMR
vaccine clinics expanded at high-risk locations
WHO Guidelines: MMR Two-Dose Strategy Critical
WHO/CDC Recommendations:
1️⃣ MMR Dose 1: 12-15 months (93%
effective)
2️⃣ MMR Dose 2: 4-6 years (97%
effective)
3️⃣ Catch-up: Any age, single dose
93% protection
4️⃣ Outbreak: Immediate
vaccination ring
5️⃣ Quarantine: 21 days for
exposed unvaccinated
Breakthrough Cases: 13 fully vaccinated SC
cases show waning immunity (15-20 years post-vaccination) + primary
vaccine failure (3-7%).
Expert Reviews & Controversy
Dr. Paul Offit (Vaccine Education Center): Highlighted
evidence from South Carolina showing a decline below the estimated 95%
vaccination coverage necessary to preserve herd immunity.
Dr. Peter Hotez (Baylor): "Religious/philosophical
exemptions created perfect storm. PAHO may revoke US measles elimination
status."
Anti-vaccine Pushback: Local groups claim
"natural immunity better," despite 574/646 SC cases in unvaccinated.
School Impact & Economic Toll
- 6
elementary/secondary schools fully quarantined
- Clemson/Anderson
Universities: Sports events canceled
- $1.4M
federal aid requested for testing/quarantine
- Hospitalizations:
43 children critical, 12 ventilated
Conclusion
South Carolina's 646-case measles catastrophe + Virginia
interstate spread signals US measles elimination status at risk. WHO's
two-dose MMR strategy remains gold standard, but waning immunity gaps
demand booster campaigns. Schools must enforce vaccination—or face annual
epidemics.
Disclaimer: Health information only. Consult
healthcare providers for vaccination advice. Data current as of Jan 21, 2026.
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