A second child in Texas with measles has died as the outbreak of the childhood disease reached nearly 500 cases in the state, officials have said.
The unvaccinated schoolgirl, who had no underlying health conditions, died on Thursday in hospital from measles pulmonary failure, the Texas Department of State Health Services said.
She was being treated for complications from the illness, a spokesperson for University Medical Center Children's Hospital in Lubbock said in an email.
The girl was recently diagnosed with the viral disease, NBC, Sky's US partner said, quoting from the hospital's statement issued on Sunday.
Two children have now died in Texas since an outbreak of measles in late January in Gaines County, where the vaccination rate is about 82%, below the 95% believed to ensure those who cannot be vaccinated are safe.
An adult in New Mexico is also suspected of having died from measles, NBC said, calling the deaths the first from the disease in the US for 10 years.
US President Donald Trump, speaking to reporters on Air Force One on Sunday, said that, if the outbreak continues, his administration will "have to take action very strongly".
US Health and Human Services Secretary Robert F Kennedy Jr, identified the child as eight-year-old Daisy Hildebrand and said he visited Texas on Sunday to comfort the child's family.
Pictures were published of him at the girl's funeral in Seminole, northwest Texas.
In a post on X, Mr Kennedy, a vaccine sceptic who says it should be a personal choice, said vaccines are nonetheless the best protection against the illness.
He said the MMR (measles, mumps, rubella) vaccine is "the most effective way to prevent the spread of measles", confirming that, as of Sunday, there were 642 confirmed cases of measles in the US, 499 of those in Texas.
The Texas Department of State Health Services said, as of Friday, 481 cases of measles had been confirmed, a rise of 14% in a week.
They include six infants and toddlers at a Lubbock day care centre that tested positive in the past two weeks.
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Two of those children are among 56 people who have been treated in hospital for measles in the area since the outbreak started, NBC said, quoting health officials.
Measles is one of the most contagious viruses for humans. In serious cases, infections can cause complications including pneumonia, encephalitis, dehydration and blindness.
The Texas Department of State Health Services described it as a "highly contagious viral infection, which can cause life-threatening illness to anyone who is not vaccinated".
Early symptoms can include a fever, cough and a runny nose, developing into a red-brown rash and high temperature.
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