What to know about measles breakthrough cases and why vaccination is still important

“We know that the measles vaccine is highly effective,” Dr. Dan Barouch, the William Bosworth Castle professor of medicine and professor of immunology at Harvard Medical School, told ABC News.

“However, it’s not 100%, so a small percentage of people can still develop measles, even if they receive a measles vaccine,” he continued. “In most cases, such cases of measles is less severe than in an unvaccinated individual.”

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“Measles is one of the most contagious viruses that we know about, so it will spread like wildfire in an unvaccinated population,” Barouch said. “Whenever population immunity is less than 95%, then we see outbreaks. … The outbreak will continue to spread as long as a fraction of the population is unvaccinated.”

What to know about measles breakthrough cases and why vaccination is still important – ABC News