• Measles is surging in a Texas outbreak, but doctors say most adults don't need a booster shot.
• Consider another measles vaccine if you're unsure whether you had both shots, or if you got them before 1968.
• Children may also get an early dose if traveling to high-risk areas.

Amidst a growing measles outbreak in Texas, your childhood shots are likely enough to keep you safe from the highly-contagious illness, according to doctors.

Having both recommended doses of measles vaccine offers about 97% effectiveness against infection— enough protection for most people, said pediatrician Dr. Michael Glazier, chief medical officer and co-founder at Bluebird Kids Health.

"I'm not worried that I'm going to get measles or that I need another dose," Glazier told Business Insider.

Outbreaks are still cause for public health concern, as measles is exceptionally good at spreading from person to person. Areas with lower rates of vaccination are vulnerable to a surge in cases.

"It's one of the most contagious diseases out there," Glazier said. "If what's happening in Texas is a harbinger of having more pockets of children that aren't vaccinated, it will become a much more widespread issue."

You may need extra protection if you're unsure of your vaccine record, got an obsolete version of the shot, or plan on traveling to a high-risk area. Here's what to know.

People vaccinated before 1968 may need a booster

The first step in protecting against measles is to know your vaccine status, according to Dr. William Moss, professor of epidemiology at Johns Hopkins Bloomberg School of Public Health and executive director of the International Vaccine Access Center.

If you were vaccinated before 1968, you might benefit from a booster.

Earlier versions of the vaccines aren't as effective, Moss said, so older Americans may want to talk to their doctors about re-upping their immunity.

Consider a measles booster if you're unsure of your vaccine history

Another reason to consider a booster is if you can't confirm you had both doses of the vaccine, Glazier said.

If that's the case, it's worth thinking about a precautionary shot.

"The issue is that a lot of people don't know," he said. "If you're unsure, get another one. There's no harm whatsoever."

Measles isn't something to gamble on, since it can lead to serious health consequences like pneumonia or brain inflammation.

"It's not the benign disease people make it out to be," Glazier said. "Saying 'I had measles and it was fine,' I liken it to saying "I never wore a seatbelt, and I was fine.'"

If you only had one shot, you're still likely to have solid protection, but may want to consider a booster if you're immune-compromised, caring for someone who is, or are in a high-risk situation, such as a healthcare setting or outbreak area.

"It's an individual judgment call in consultation with a healthcare provider," Moss said.

Children under a year old can get an early dose

One of the biggest concerns about the current outbreak is the recent death of a child, the first measles death in the US since 2015, Moss said.

"That's completely preventable, it's tragic, we should not be having childhood deaths from measles in the United States," he said.

Children are typically protected from measles by one shot administered between 12 and 15 months old, and a second between ages four and six.

In cases of international travel to areas with a higher exposure risk to measles, the CDC recommends an earlier precautionary shot to infants as young as six months.

If you're in or near a current outbreak area, it's worth talking to your doctor about whether that might apply to your child, according to both Moss and Glazier.

With a rise in vaccine hesitancy in recent years, parents should understand what's at stake in staying up-to-date on recommended vaccines.

"The assumption is that every parent wants to do what's best for their children," Moss said. "What happens is that parents can underestimate the risk of a disease like measles, and overestimate the risk of a vaccine."

• The measles vaccine first became available to the public in 1963.
• Before the vaccine, measles was an endemic disease. Most children got it before turning 15.
• By 1981, the number of reported measles cases in the US had dropped 80%.

Before the measles vaccine was developed, over 30 million cases of the disease were reported worldwide each year.

What began as a fever, cough, and rash could develop into complications such as pneumonia or brain swelling, leading to hospitalization or death.

The vaccine became available in 1963, and endemic measles was eliminated in the US by the year 2000. However, outbreaks still occur among unvaccinated populations.

In February, an unvaccinated child in Texas died of measles amid an outbreak of the disease — the first reported measles fatality in the US in nearly a decade.

Here's a look back at what life was like before the measles vaccine.

Before a measles vaccine existed, the disease was endemic, meaning it was consistently present in specific regions and populations.

Most children came down with measles by the age of 15, according to the CDC.

A highly contagious disease, measles caused over 2 million deaths globally each year, according to the World Health Organization.

The mortality rate was higher than whooping cough and scarlet fever, and there was no known cure.

Authorities tried to contain outbreaks by instituting quarantines.

The quarantines often weren't strictly enforced, causing epidemics to worsen.

In the US, medical warnings were posted on the doors of some households where residents were infected with measles to prevent further spread.

Quarantines were more difficult to enforce in lower-income neighborhoods with tenement buildings and multiple families per household.

Measles was so common that it became part of pop culture with portrayals in Hollywood films.

Characters contracted measles in movies such as the 1959 film "Count Your Blessings."

All of that changed when John F. Enders developed the first measles vaccine, which became available to the public in 1963.

Enders and Thomas C. Peebles isolated the measles virus in the blood of a 13-year-old boy named David Edmonston and developed it into the first measles vaccine, according to the CDC.

In 1968, Maurice Hilleman developed a new measles vaccine that remains in use today.

By 1981, the number of reported measles cases had dropped 80% in the US.

After a resurgence of measles outbreaks in 1989, health officials instituted a second dose of the measles vaccine for children.

Children are 93% immune after their first dose of the measles vaccine and 97% immune after the second dose.

The Centers for Disease Control marketed the vaccine with bumper stickers, buttons, and comic strips in their efforts to eradicate the disease.

Endemic measles was eliminated in the US in 2000, according to the CDC, but anti-vaccine misinformation has gained momentum in recent years. The disease continues to spread among children and adults who are unvaccinated.

In 2019, there were more measles cases in the US than in any year since 1994.

Robert Redfield, then director of the CDC, attributed the outbreaks to widespread vaccine skepticism.

"Measles is preventable and the way to end this outbreak is to ensure that all children and adults who can get vaccinated, do get vaccinated," he said. "Again, I want to reassure parents that vaccines are safe, they do not cause autism. The greater danger is the disease the vaccination prevents."

In February, an ongoing measles outbreak in Texas and New Mexico killed one unvaccinated child and sickened over 130 people, marking the first measles fatality in the US since 2015.

Robert F. Kennedy Jr., a prominent anti-vaccine figure who was recently confirmed as health secretary of the US, said in a Cabinet meeting Wednesday that "we have measles outbreaks every year" and the situation was "not unusual."

The White House did not immediately respond to a request for comment.