CNN
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New research shows that daily childhood vaccination rates continue to decline, with up to 51 million people sick in 25 years, measles could become endemic in the United States.
The disease is endemic in some other countries, but it means it occurs regularly within local and community, but was declared excluded in the United States in 2000 due to a vaccination effort with the highly effective measles-Munz-Rubella (MMR) vaccine.
More than 900 measles cases have been recorded in the US this year, according to a CNN tally using data from the state’s health department and the U.S. Centers for Disease Control and Prevention. In the decade since measles was declared excluded in the United States, there have been more cases, with one more year only.
More than half of US states have reported at least one case this year, but the majority are linked to an outbreak that is primarily in areas in West Texas, where no vaccinations have been received. Two children and one adult – died, and all were not vaccinated.
The new model, published Thursday in JAMA, examines the potential for disease spread in the United States over 25 years, based on various vaccination levels calculated using data from 2004 to 23.
Researchers at Stanford, Baylor, Rice and Texas A&M University estimate current state-by-state vaccination coverage for measles between 87.7% and 95.6%.
Measles is so contagious, experts say the only way to prevent an outbreak is when at least 95% of the community receive two doses of the MMR vaccine. However, after this rate was maintained for 10 years, compensation has been immersed during the Covid-19 pandemic and has not yet recovered. According to CDC data, vaccination rates for kindergarten children from 2023 to 2024 fell to 92.7%.
At current vaccination rates, the model predicts that the disease will become endemic in the US within 25 years.
If vaccination rates drop by 10%, the US will see 101.1 million measles cases during this period.
However, if the current trend is reversed and the number of people taking the MMR vaccine increases by 5%, there will only be 5,800 measles cases in 25 years.
This model showed that other vaccine-protectable diseases should not be endemic in the US at current vaccination levels. However, if daily pediatric vaccinations fall by 50%, we predict 51.2 million measles cases, 9.9 million rubella cases, 4.3 million poliomieritis, and 197 diphtheria cases over 25 years. As these vaccinations have dropped sharply, these diseases result in 10 million hospitalizations and 159,000 deaths.
“These findings support the need to continue with high coverage and routine childhood vaccinations to prevent the revival of vaccines that can be prevented infectious diseases in the United States,” the researchers wrote.
One limitation of this study is that it does not take into account the possibility that vaccination rates may fluctuate from community to community. Essentially, states have got their own buckets, said Dr. Mujeeb Basit, a modelling expert on the spread of diseases that are not involved in new research.
“But the problem with that is that we are comparing Texas to a small state like Rhode Island. So, it’s not a homogeneous distribution by size, so the accuracy of numbers fluctuates.”
However, he said the problem was computationally difficult and the researchers took a “really great approach.”
Such research is important, he said. This is because the continued trend in vaccination clearly indicates that the US can experience a continuous outbreak of measles, which has a cascade effect on the healthcare system.
“Hopefully it will make people think,” he said — and take action and get protection through vaccinations.