SEATTLE — A current spike in measles cases in the U.S. might have some wondering if they should get a measles booster shot, even if they were vaccinated as a child.

An infectious diseases doctor in Seattle said more of his adult patients are inquiring about this. 

"I would say my colleagues in pediatrics often think about measles much more frequently, but unfortunately, even in adult medicine, now we have to be thinking about it as well," said Dr. Seth Cohen, the medical director of infectious diseases at UW Medical Center. "I think there is a more general awareness that people may not be immune, or there may need to be additional boosters," Cohen added. 

As of late February, outbreaks in Texas, including a confirmed case in King County, Wash., have medical circles underlining the importance of measles, mumps and rubella vaccination. 

CDC guidelines say adults who have documentation of MMR vaccination as children should have sufficient immunity and adults who were born before 1957 -- regardless of vaccination -- are presumed to have natural immunity because of the prevalence of measles at the time.

"But for people born after '57 or people who just aren't sure about their immunity or maybe only received one dose of the vaccine, that's when we need to start thinking about do they need a booster or should they just go to their doctor to get their titers checked to see if they're actually immune," Cohen said. 

Cohen emphasizes the measles vaccine is highly effective, with no association with autism.

"That has been thoroughly debunked in the paper that was initially written about this; has been retracted, and basically every vaccine expert, every infectious disease doctor vaccinates their children because we strongly believe in vaccines, their safety, and their efficacy," Cohen said. 

Cohen said with measles cases popping up, it doesn't hurt to undergo a titer, which is checking antibody levels from a blood test. 

Travel plans might also be reason to ask about checking for immunity. 

"There's still a lot of measles out there internationally and so if you're traveling, it's a great idea to make sure that you talk to your doctor and make sure that you have enough antibodies in your body to protect you against measles should you come across it," Cohen said. 

However, Cohen said pregnant women or those with compromised immune systems should consult with their doctor before pursuing a measles booster. The ultimate concern, doctors say, is how contagious the measles virus is.

"It is a very smart virus, and at this point, I am much more concerned or scared about measles than I am about COVID for example, and COVID is still very serious in our community," Cohen said. 

The stakes are high, considering the level of immunity the U.S. achieved at the turn of the millennium. 

In 2000, measles was declared to have elimination status in the U.S., meaning there was no continuous spread of the disease in a span of a year -- a status that has, in recent years, been at risk.