- Adults in the United States who were vaccinated against measles decades ago may need a new dose depending on when they received the shot and their exposure risk, according to public health experts battling the nation’s largest outbreak since the virus was deemed eliminated in 2000.
Dr. Allison Bartlett, an infectious disease expert at the University of Chicago Medicine, said the “continued vulnerability to infection” is why high-risk adults such as healthcare workers are routinely advised to get a second dose of the measles vaccine if they have not had one.“It’s complicated and often futile because it's very difficult to resurrect those old records,” said Dr. William Schaffner, an infectious disease expert at Vanderbilt University Medical Center.
Merck & Co Inc is the sole U.S. provider of the MMR vaccine. The company said in a statement that it has “taken steps to increase U.S. supply” of the vaccine due to the current outbreak. The measles virus is highly contagious and can cause blindness, deafness, brain damage or death. It is currently spreading in outbreaks in many parts of the world.
In general, the CDC says two doses of the measles vaccine should provide 97 percent protection; one dose should offer 93 percent protection. However, immunity can wane over time.
Imported and weaponized measles.