Measles Testing of Persons with HIV
October 30, 2025
By Carol A. Kemper, MD, FIDSA
Synopsis: A Dallas County human immunodeficiency virus (HIV) clinic review from 2015-2025 found that only 11% of people with HIV had documented measles immunity, with younger patients, white and Hispanic patients, and patients with low CD4 counts more likely to be seronegative.
Source: Andrews HS, Blanchard HL, Yang S, Utay NS. Low rate of documented measles immunity in a large urban HIV clinic. Clin Infect Dis. 2025;May 28:ciaf278. doi: 10.1093/cid/ciaf278. [Online ahead of print].
Measles immunity generally is presumed based on age (birth prior to 1957); prior receipt of two measles, mumps, rubella (MMR) vaccines; or documentation of measles immunoglobulin G (IgG) serology. Detection of measles-specific IgG antibody by enzyme-linked immunosorbent assay (ELISA) is a standard means to confirm serologic immunity, although some might argue that detection of cell-mediated immunity using the more tedious plague-reduction neutralization assay more directly correlates with true immunity.
Persons with human immunodeficiency virus (HIV) infection (PWH) are at increased risk for more severe measles infection, especially those with lower CD4 cell counts. Earlier reports suggested that mortality for measles infection in acquired immunodeficiency syndrome (AIDS) may be as high as 40%. Earlier seroprevalence studies observed serologic immunity in 70% to 92% of PWH, but younger immigrants may be at particular risk for inadequate immunity. Previously, such individuals were relatively protected from measles infection by high levels of immunity in the general public. But as vaccine rates fall, this community protection is no longer a given, and the recent measles outbreak in Texas increased concern for those with HIV.
As a result, clinicians at a large urban Dallas County, TX, HIV clinic performed a retrospective review of presumed measles immunity of persons attending a large Ryan White-supported clinic system from 2015-2025. Adults ≥ 18 years of age who had been seen in the clinic at least once were included in the review. Records were assessed for birth before 1957, documentation of at least one dose of MMR, and documentation of serologic test results. Demographic and clinical traits were collected for those with documented measles serologic testing.
Only 1,531 of 13,622 (11.2%) patients had documentation of presumed measles immunity, including 6.6% born before 1957, 3% with a documented dose of MMR, and 1.9% with a confirmed measles IgG antibody. Serologic testing had been performed in 311 individuals, with a positive result in 253 (82%). A negative serology was associated with younger age, Hispanic ethnicity, birth in Latin America, and a history of AIDS-related malignancy. However, in multivariate analysis, predictors of seronegativity were age ≤ 35 years, being white, and a CD4 count < 200 cells/microliter. Of those 34 individuals with a negative serology and eligibility for measles vaccination (CD4 counts > 200 cells/microliter), only 10 (29%) had received vaccination.
Commentary
The authors recommend verifying measles immune status for any PWH attending your clinic. If vaccine records cannot be confirmed, consider adding a measles IgG serology to their next routine testing. Given how many PWH may have existing immunity, a strategy of first testing and confirming immunity, with selective vaccination of eligible seronegative patients with CD4 counts ≥ 200 cells/microliter second, is appropriate.
Carol A. Kemper, MD, FIDSA, is Medical Director, Infection Prevention, El Camino Hospital, Palo Alto Medical Foundation.