Few people expect to get measles after getting the measles vaccine – or give it to someone else. But in the case of a 22-year-old New York woman, she not only got the measles, but gave it to four other people. This startling case study reported in Clinical Infectious Diseases suggests that a recent swell of measles outbreaks in developed nations could mean more illnesses even among the vaccinated.
Most people in the United States are initially vaccinated against the virus shortly after their first birthday and return for a booster shot as a toddler. Less than 1% of people who get both shots will contract the potentially lethal skin and respiratory infection. And even those who do are typically not thought to be contagious.
That’s why doctors didn’t think it strange to release the woman without hospitalization or quarantine, however, this patient –known as “Measles Mary” — turned out to be unwittingly contagious. She ultimately passed the disease on to four other people according to research that tracked symptoms in the 88 people with whom she interacted while sick.
Although public health officials have assumed that measles immunity lasts forever, the case of Measles Mary highlights the reality that no one is clear about how long measles immunity lasts. The possibility of waning immunity is particularly worrisome as the virus surfaces in major U.S. hubs like Boston, Seattle, New York, and the Los Angeles area.