United States: Since the beginning of the year, NBC News reports that 800 Americans have developed measles.
The highest number of measles cases exists in West Texas because an ongoing outbreak began its spread in January.
More about the news
Breakthrough infections comprise 3% of all identified measles cases, yet almost every person diagnosed became sick after avoiding vaccination.
The measles, mumps, and rubella (MMR) vaccination failed to protect 3% of those who became sick even though they received full or partial vaccinations through this regimen.
Experts from infectious diseases medicine confirm that the MMR vaccine stands as a top-rated vaccine, yet Rodney Rohde from Texas State University explains that during major outbreaks, some vaccinated individuals may still develop the disease.
The MMR vaccine provides 93% protection after one dose, yet administering a second dose raises this effectiveness to 97% in preventing measles infection.
What causes breakthrough measles infections even if someone is vaccinated? ppl experiencing severe symptoms from a breakthrough infection may have had a single vaccine dose that still offers significant protection, not as much as the full 2-dose regimen https://t.co/BWs9C80lKt
— Martha Young-JD, MBA, PCC-😷 (@mryoung151) April 20, 2025
What are the experts stating?
“The vaccine is highly effective,” Rohde stated.
“But it means that after two doses, while 97 out of 100 people will develop strong immunity and be protected if exposed to measles, the remaining three out of 100 could still be vulnerable,” he stated.
Professor Rodney Rohde states that serious breakthrough cases among fully vaccinated people are possible, though extremely unlikely, during the current outbreak.
“They could fall into one of those small percentages that got the full vaccine but just didn’t respond,” he noted.
The individuals affected by measles might not have known they lacked complete protection from the disease through vaccination.
Studies show that MMR vaccination still supplies some protective benefits against it even when breakthrough infections from measles occur.
“If someone vaccinated does get measles, it’s often a milder version, sometimes called modified measles,” as per Rohde.
“A rash can still occur, but it may be less widespread [across the body], fainter or atypical, meaning it doesn’t follow the classic pattern of starting at the hairline and spreading downwards. Fever is also less common or has a lower grade. In classic measles, fevers can spike over 104 degrees Fahrenheit, but in modified cases, it’s often milder or absent,” as per the expert.
Common measles symptoms
The same is true for other common measles symptoms, as per the reports:
- Cough
- Runny nose
- Conjunctivitis, or red eyes
“They may still occur but are often less intense,” he noted.
“Koplik spots, which are tiny white spots in the mouth, are less commonly seen. Breakthrough cases are also generally less contagious but still a potential source of transmission,” the experts state.
The Texas Department of State Health Services indicates that people remain contagious from four days before the rash starts to four days after its appearance. The rash shows itself fourteen days following contact with the virus.