Vaccine Update: Recent Measles Cases Highlight the National and Global Rise of this Highly Contagious Disease

Column Author: Christine Symes, RN, MSN, CPNP-PC 

Column Editor: Angela Myers, MD, MPH | Pediatric Infectious Diseases; Division Director, Infectious Diseases; Medical Director, Center for Wellbeing; Professor of Pediatrics, University of Missouri-Kansas City School of Medicine; Clinical Assistant Professor of Pediatrics, University of Kansas School of Medicine

An old foe is rearing its head: cases of measles are on the rise. The Centers for Disease Control and Prevention (CDC) reports that 56 cases of measles were confirmed in the United States in 2023 in 20 different jurisdictions.¹ As of Jan. 17, 2024, 12 cases had already been identified in the following states: Delaware, Georgia, Missouri, New Jersey, Pennsylvania, Virginia and Washington. Specifically in Pennsylvania, the index case contracted measles while traveling abroad and was then hospitalized and returned to child care before a diagnosis was made. So far this one case in Philadelphia has accounted for a total of eight cases, five of them children. This reality highlights the need to be vigilant when evaluating a child with non-specific symptoms of fever, upper respiratory tract infection symptoms and rash. The typical presentation of measles is fever, cough, coryza and conjunctivitis followed by a maculopapular rash that starts on the face and spreads in a cephalocaudal and centrifugal pattern. During the prodrome period, an enanthema called Koplik spots may be present and appear as erythematous, white or gray specks on the buccal mucosa. The incubation period is generally eight to 12 days from exposure to onset of symptoms. Testing is done by sending serum measles IgG and IgM levels and a throat or retropharyngeal swab for PCR testing that is performed by the state health department lab, if the patient meets criteria for testing. Any suspected case of measles should be reported to the local health department as soon as possible.

Treatment of measles includes supportive care and vitamin A therapy, which is recommended for all patients diagnosed with measles. Vitamin A has been found to decrease morbidity and mortality rates.² Dosing is given immediately after diagnosis and repeated the following day for a total of two doses. Dosing is as follows: 200,000 IU for those 12 months of age or older, 100,000 IU for those 6-11 months of age, and 50,000 IU for infants younger than 6 months. A cornerstone of care is also isolation of any suspected or confirmed cases with airborne transmission precautions for four days after the onset of rash in otherwise healthy children and for the duration of the illness for children with an immunocompromising condition.

For those who are exposed but have received two doses of measles-mumps-rubella (MMR) vaccine or are known to be measles IgG positive, no post-exposure prophylaxis is needed. For those less than 6 months of age, intra-muscular immune globulin (IMIG) should be given.² Patients >6 months of age who are non-immune should be given the MMR vaccine within 72 hours of exposure. Beyond that, they should receive IMIG. Patients >12 months of age who have received only one dose of MMR vaccine should receive a second dose of vaccine if it is at least 28 days after the first dose. For more specific information about length of quarantine and post-exposure prophylaxis for those who are immune compromised, refer to the CDC or the Red Book recommendations.

Recommended vaccination schedule is a series of two doses of vaccine, generally given at 12-15 months of age and again at age 4-6 years. Children 6-11 months of age who are in an outbreak environment or are going to be traveling internationally should receive a dose of MMR vaccine at least two weeks prior to travel. This dose DOES NOT count toward the two-dose series that should be given per the routine vaccine schedule. An older child who has received only one dose of MMR vaccine should receive a second dose if it is at least 28 days after dose #1. This dose DOES count toward the two-dose series even if given before age 4 years. Anaphylaxis to neomycin or gelatin is a contraindication to vaccine, but allergy to eggs and non-anaphylactic allergy to neomycin or gelatin are not contraindications to MMR vaccine. For those who have received an immune globulin product, blood product, high-dose steroid therapy or other immune suppressive medication, the response to vaccine can be impaired. Refer to the Red Book for guidelines on timing of MMR vaccine in these situations. For some immunocompromised children, live vaccines like MMR are contraindicated and should be evaluated on a case-by-case basis.

The rate of MMR vaccination has been falling for several years in the United States. A population with an immunization rate <95% is at risk for outbreaks. For the school year 2022-2023, the rate of complete MMR vaccination for children entering kindergarten in Missouri was 91.3%.³ For Kansas the rate was 91.04%.⁴ Globally, these rates reflect a trend. The CDC and the World Health Organization published a warning in late 2023 stating, “measles continues to pose a relentlessly increasing threat to children.” They reported measles cases increased 18% in 2022 and deaths increased 43%, leading to an estimated 9 million cases of measles and 136,000 deaths that were mostly in the pediatric population.⁵

Assessing vaccine status and offering appropriate vaccines at every health care encounter is now more important than ever. Discussing vaccines and answering questions to alleviate fear in vaccine-hesitant caregivers remains vital. In this time of rising case rates and identification of local cases, pediatric health care facilities should have and review procedures for identifying and evaluating potential cases, isolation in suspected cases, testing, treatment, post-exposure prophylaxis, and identification of those patients who are non-immune.

References:

1. Measles cases and outbreaks. Centers for Disease Control and Prevention. Last reviewed January 26, 2024. https://www.cdc.gov/measles/cases-outbreaks.html
2. Patterson J, Ellis D. The Red Book. New York: Little, Brown and Company; 2021.
3. Missouri school immunization rates: kindergarten. Missouri Department of Health and Senior Services. Updated August 1, 2023. https://health.mo.gov/living/wellness/immunizations/pdf/KindergartenData.pdf
4. Kindergarten immunization coverage survey. Kansas Department of Health and Environment. https://www.immunizekansascoalition.org/datadash.asp
5. Minta AA, Ferrari M, Antoni S, et al. Progress toward measles elimination — worldwide, 2000–2022. MMWR Morb Mortal Wkly Rep. 2023;72:1262-1268. doi:15585/mmwr.mm7246a3