Just how contagious is measles anyway?

The measles outbreak has grown to at least 75 cases in six states. The vast majority are linked to Disney theme parks in Southern California. The rate at which the measles has spread highlights just how infectious the virus is.

On average, a person with measles sickens 12 to 18 unvaccinated people. In comparison, a person with the flu infects one to four and someone with Ebola infects two to three. The measles vaccine is 97 percent effective in those who have received two doses. The death rate is about one in 1,000 but the complication rate is as high as one in three.

measlesupdates.jpg
CBS News

"It can result in death," said Dr. Jane Seward with the Center for Disease Control and Prevention. "It can result in brain damage, it can result in hospitalizations and someone being very, very sick."

The CDC says people are considered immune if any of the following are true:

  • They were born before 1957, therefore likely exposed to measles
  • They have documentation of adequate vaccination
  • A blood test suggests immunity

The CDC suggests people without immunity discuss vaccination with their health care providers. Clearly there's room for improvement. Depending upon the state, the vaccination rate for toddlers ranges from 86 percent to 96 percent; in California the rate is 91 percent.

  • Jonathan LaPook

    Dr. Jonathan LaPook is the chief medical correspondent for the CBS Evening News. Follow him on Twitter at @DrLaPook