Postexposure Prophylaxis Proves Effective Against Measles in Infants

As the United States grapples with the most significant measles resurgence in decades, health care professionals are refining clinical protocols to protect the most vulnerable populations. A recent report published in NEJM Evidence highlights a critical development in postexposure prophylaxis for infants under 12 months of age, who are too young for the standard measles, mumps, and rubella vaccine and face a high risk of severe disease.¹

Because the intramuscular immunoglobulin dose is weight-based at 0.5 ml/kg, infants often require large volumes that lack clear administration guidelines. To address this, the Utah Department of Health and Human Services developed a protocol during a 2025 exposure event that limited injections to 1.5 ml per vastus lateralis muscle, sometimes requiring 3 or 4 separate injection sites for larger infants. This standardized approach, which has since been used for dozens of infants in Utah without serious adverse events, provides a vital roadmap for pharmacists and clinicians managing high-volume prophylaxis in emergency settings.

Measles Resurgence in Utah and Beyond

This innovation comes as Utah manages its largest measles outbreak in 40 years, with a total of 673 residents diagnosed as of May 2026. The crisis in Utah intensified rapidly, with 476 cases reported in 2026 alone following 197 cases in 2025.²

Public health officials have utilized advanced tracking methods, including a wastewater dashboard to detect viral shedding in communities, and have identified numerous exposure locations ranging from pediatric clinics to middle schools. The state's response has been hampered by a significant gap in immunity, with 12% of Utah kindergarteners having been exempted from the MMR vaccine or lacking proper documentation during the 2025-2026 school year. This lack of coverage has led to widespread community transmission, forcing health officials to recommend early, extra MMR doses for infants as young as 6 months.²

“Public health needs to navigate the new normal of vaccine hesitancy and doubt. As these sentiments become more pervasive in some populations, so will measles and other vaccine-preventable diseases,” Demetre Daskalakis, MD, MPH, said.³ “The current policy environment in many states that facilitates avoidance of vaccination—many now with vaccine exceptions over 5%, making 95% population immunity impossible—will need to be revisited with an eye toward being responsive to misinformation in a meaningful way.”

The situation in Utah is a microcosm of a broader national emergency for the American health care system. Following a 30-year high of 2281 cases in 2025, the US recorded 1136 cases in just the first 2 months of 2026, putting the nation's 2000 elimination status under severe threat.⁴

Although Utah has been a recent focal point, Texas saw a massive spike with over 720 cases by mid-2025, largely concentrated in communities where vaccination rates had plummeted to as low as 50%. Nationally, MMR coverage among kindergartners has slipped to 92.5%, falling below the critical 95% threshold required for herd immunity. This decline leaves approximately 286,000 children vulnerable to a virus so contagious that a single infected individual can spread it to 12 to 18 others.^3,5

The Role of the Pharmacist

For pharmacists, the resurgence is both a logistical challenge and a communication crisis. Managing even a single measles case involves intensive contact tracing and testing that can cost nearly $60,000. Furthermore, pharmacists are on the front lines of a deepening misinformation battle. Recent surveys indicate that one-third of adults have heard the false claim that the measles vaccine is more dangerous than the infection itself, while others mistakenly believe vitamin A can prevent the disease. Clinical experts emphasize that while vitamin A can treat complications of an active infection, it cannot prevent the virus, and the long-debunked link between vaccines and autism continues to fuel hesitancy.^5,6

To mitigate the spread, pharmacists are being encouraged to move beyond simple myth-busting and instead utilize motivational interviewing to build rapport with hesitant parents. By normalizing routine vaccinations as standard care and serving as accessible community resources, pharmacists can help bridge the trust gap exacerbated by shifting federal policies that frame vaccination as a personal choice rather than a public health necessity.^3,5,6

“Trust is something that, in most cases, needs to be earned, and if that trust is lost, it is a very difficult hill to overcome to regain that trust,” Lauren Angelo, PharmD, associate dean for academic affairs at Rosalind Franklin University in North Chicago, Illinois, said in an interview.⁶ “I think to build that trust and rapport, we need to be present and we need to be seen as a resource within our community. If we’re able to step outside of the pharmacy and offer clinics or educational sessions that are offsite and during extended hours so patients can attend, that will go a long way in building that trust and rapport and working at that individual level with specific patients.”

As the Pan American Health Organization prepares to review the United States' elimination status in November 2026, the role of the pharmacist in providing evidence-based education and maintaining high vaccination thresholds has never been more critical to preventing a permanent return of this once-conquered disease.^3,5,6

READ MORE: Infectious Disease Resource Center

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REFERENCES

1. Weil A, Jones A, Mansfield K, Pavia AT, White A, Nolen LD. Intramuscular Immunoglobulin for Measles Postexposure Prophylaxis. NEJM Evid. 2026;5(6):EVIDpha2600093. doi:10.1056/EVIDpha2600093

2. Utah Department of Health and Human Services. Utah measles outbreak response. Updated May 19, 2026. Accessed May 27, 2026. https://epi.utah.gov/measles-response/

3. Nowosielski B. “Canary in the Coal Mine:” Navigating the 2026 Measles Resurgence After Eliminating the Disease. Drug Topics. March 5, 2026. Accessed May 27, 2026. https://www.drugtopics.com/view/canary-in-the-coal-mine-navigating-the-2026-measles-resurgence-after-eliminating-the-disease

4. American Hospital Association. Utah measles outbreak climbs to 638 cases. May 8, 2026. Accessed May 27, 2026. https://www.aha.org/news/headline/2026-05-08-utah-measles-outbreak-climbs-638-cases

5. Gallagher A. As Measles Outbreak Continues, Misinformation Continues to Grow. Drug Topics. April 24, 2025. Accessed May 27, 2026. https://www.drugtopics.com/view/as-measles-outbreak-continues-misinformation-continues-to-grow

6. Gallagher A. Measles Outbreak Reaches Over 800 Confirmed Cases in the US. Drug Topics. June 7, 2025. Accessed May 27, 2026. https://www.drugtopics.com/view/measles-outbreak-reaches-over-800-confirmed-cases-in-the-us