This is an evolving situation, and as of the update of this post on 3/6/25 I am not aware of any evidenced-based guidance from any major medical society or the CDC on the specific outbreaks in Texas, but we are already receiving lots of questions on this.
Therefore all guidance would be based on existing guidelines related to MMR vaccines and measles exposure, which in brief includes the following:
Texas Measles Outbreak 2025
There is an outbreak of measles mainly in Gaines and surrounding counties, a total of 159 cases thus far reproted in Texas, and 8 in New Mexico. Nearly 3/4 are in patients less than 18 years old. There have been 32 hospitalizations and one death of a school aged child.
Measles Disease:
Rubeola is also called measles. It is characterized by a Rash (see pictures below), cough, high fever, runny nose, sore throat, diarrhea, vomiting, red/watery eyes, enlarged lymph nodes. The rash is the most distinctive symptom, and usually appears 2-4 days after the onset of other symptoms. The virus is highly contagious and has been reported to be able to survive outside the human body for up to 2 hours.
What Counts as already being 'immune':
being born before 1957 (it is presumed these patients were all exposed and developed natural immunity as measles was widespread then)
written documentation that you have received the vaccine before ('MMR' vaccine, 2 doses)
lab 'titers' showing that you have antibodies
Is there a recommendation for a 'booster' if you have already had the vaccine:
as of now there is no recommendation for this for most adult patients (exception below)
Exception- if received the vaccine between 1963-1967:
about 5% of the population during these years received a form of the vaccine that is now thought to not have been effective ('killed / inactivated' vaccine), the remainder received a live vaccine that was effective
For patients who a) were born or received the vaccine from 1963-1968 AND b) whose vaccine type is not known or if it was the 'killed / inactivated' version thought to be not effective, then those patients are recommended to get revaccinated now
Concern about exposure / West Texas outbreak:
As of now, there is not a CDC or State recommendation for adults who are otherwise immune (per above) to obtain additional vaccine doses
The MMR vaccine is thought to confer lifelong immunity (e.g. this was the reason to receive the vaccine in the first place in case you were ever exposed to a case)
KNOWN exposure to an active case:
Post-exposure prophylaxis- if you know you were exposed to a confirmed positive measles case AND you are NOT vaccinated (or cannot be sure you have had the MMR vaccine per the above guidelines), then a post-exposure prophylaxis vaccine and/or IgG could be administered.
An exposure plus infectious signs / symptoms (fever, rash, fatigue, cough, congestion) at this point would be best managed by presenting to a local ED and alerting them to the concern.
Concern about if vaccine was effective or unsure if you have received:
If you are truly unsure if you have had the vaccine, titers (a blood test) can be obtained to ascertain if you have had and still have immunity. This test is called 'Rubeola IgG.'
Per above, obtaining titers is not considered to be necessary if you have documentation that you have received the vaccine or if you were born before 1957
T and B Cell Immunity
'Titers' only test for circulating antibodies, one form of immunity
However T and B cell memory also serves as a form of immunity, which there is not a readily available way to test; if you had exposure or the vaccine you likely have this type of immunity also
Another good summary:
Measles rash photos:
CDC Measles vaccine recommendations: https://www.cdc.gov/vaccines/vpd/mmr/hcp/recommendations.html
Texas DSHS Alerts Updates:
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