Measles Outbreak

As you know, we are having the largest measles outbreak in many years in the US. The recent measles death in Texas underscores the critical importance of maintaining high vaccination coverage with the measles, mumps, and rubella (MMR) vaccine.

Source: Dr. Kim's Kids (Winnsboro Pediatrics)

Measles was declared eliminated in the United States in 2000, meaning there was no continuous transmission for over a year.¹ This current outbreak in Texas occurred in under-vaccinated communities; nearly all of those who have been reported ill were unvaccinated.

Measles is so contagious that if one person is infected, nine out of ten people with whom they have close contact who are not immune will become infected.² Maintaining a vaccination coverage of at least 95% in a community is essential to achieve herd immunity and prevent measles outbreaks.³

The virus is transmitted via respiratory droplets and by the airborne route as aerosolized droplet nuclei. Infected individuals are contagious from 4 days before to 4 days after the onset of the erythematous maculopapular rash, which typically appears 2-4 days after onset of fever, starting on the face and head, then spreading to the trunk and extremities. Fever is usually accompanied by at least one of the "three Cs": cough, coryza (runny nose), and conjunctivitis (pink eye) as well as Koplik spots, which are small bluish-white plaques on the inside cheeks.

Maculopapular rash on child's face - Source: CDC

In addition to vaccination, several precautions can help prevent the spread, including good hand hygiene practices, cough etiquette, masking if symptomatic, avoiding contact with infected individuals, and isolating suspected individuals / close contacts at home for at least 4 days after the onset of the rash to prevent further transmission.

So, how do you know if you're protected and whether you should get a MMR booster vaccine?⁴ It is based on the timing of your MMR vaccine(s):

• A vaccine was not available for measles, mumps and rubella until 1957, so individuals born before 1957 most likely had the disease as it was so endemic, and therefore gained natural immunity.
• The first live attenuated vaccine (LAV) was released in 1957 and induced a robust immune response, so individuals vaccinated in 1957-1962 possibly have long-lasting immunity. [They can get their blood titers checked to confirm immunity.]
• Individuals vaccinated between 1963-1967 received the inactivated vaccine, which had fewer side effects but was not as effective; so, they need a booster sometime after 1968 in order to be fully immune.
• A new LAV was available in 1968, which was more robust than the inactivated vaccine and provided a more favorable safety profile than the first LAV while maintaining high immunogenicity. However, individuals vaccinated between 1968-1989 need a second dose since the single-dose regimen used during this period was less effective in providing lifelong immunity.
• The two-dose schedule was widely implemented in 1989 to address cases of vaccine failure and to ensure long-term immunity, so individuals vaccinated in 1989 onward should have complete immunity.
• Unvaccinated individuals should receive 2 doses of the MMR vaccine.
• NOTE: A second dose given years later can still be effective.

If you fit any of these criteria or are unsure if you received a second dose, please consider getting an MMR booster vaccine. Moreover, healthcare workers, international travelers, and those in outbreak areas may require additional booster doses. Most commercial insurances cover the vaccine 100%, and you can get it at any retail pharmacy. You may also consider getting a blood titer to prove immunity. Be sure to contact your primary care physician for an individualized plan, if needed.

References:

1. Rubeola / Measles. Paul Gastañaduy, James Goodson. CDC Yellow Book.

2. Protecting the Public's Health: Critical Functions of the Section 317 Immunization Program-a Report of the National Vaccine Advisory Committee. Public Health Reports (Washington, D.C.: 1974). 2013 Mar-Apr;128(2):78-95. doi:10.1177/003335491312800203.

3. Combining Serological and Contact Data to Derive Target Immunity Levels for Achieving and Maintaining Measles Elimination. Funk S, Knapp JK, Lebo E, et al. BMC Medicine. 2019;17(1):180. doi:10.1186/s12916-019-1413-7.

4. Do You Need a Measles Booster? https://www.consumerreports.org/measles/do-you-need-a-measles-booster/

DISCLAIMER: This general information is for educational purposes and not intended to diagnose any medical condition or to replace your healthcare professional.