Immune globulins treat severe mpox in immunocompromised person living with HIV

Administering vaccinia immune globulin intravenously could be beneficial in treating mpox virus in severely immunocompromised people, according to a single-case study involving a person living with HIV (PLWH) in New York City.

About This Study

“The use of vaccinia immune globulin in the treatment of severe mpox virus infection in HIV/AIDS” was published online on Dec. 26, 2022, in Clinical Infectious Diseases. The lead author is Andrea K. Thet, M.D., of BronxCare Health System in Bronx, N.Y.

Key Research Findings

This case study describes the treatment of a 29-year-old male PLWH who was not taking antiretroviral treatment consistently] and presented at the hospital with a painful lip lesion. The lesion tested positive for mpox, and the individual was admitted to the hospital with both mpox and herpes simplex (HSV-1) infections.

Initially, the patient was treated with tecovirimat for mpox, valacyclovir for herpes, and a combination of bictegravir, emtricitabine, and tenofovir alafenamide for HIV.

However, his lesions did not improve after two weeks of treatment, and additional lesions — described as large, painful, hyperkeratotic, and fungating — formed. His lip lesions tested positive for methicillin-resistant staphylococcus aureus, so vancomycin and other medications were added. While the patient’s CD4 count increased from the initial 77 cells/µL to 204 cells/µL, mpox symptoms did not improve.

By week four, he received a single infusion of vaccinia immune globulin. A week later, his mpox lesions shrunk significantly and no new ones developed.

Discussion Highlights and Implications for Practice

Study authors theorize that, although the patient’s adaptive immune system recovered—as evidenced by the improvement in CD4 cells—his humoral immune system was not adequately restored. The IG infusion then increased his humoral immune response to the point where he recovered from mpox.

While these immune globulins are licensed in the U.S. only for eczema vaccinatum or severe vaccinia, they are available under an expanded access protocol to treat orthopoxviruses. This protocol was used in the current case to treat mpox.

In summary, severe mpox in a person living with advanced HIV infection was successfully treated with a combination of tecovirimat and vaccinia immune globulin intravenously. No side effects to this treatment were observed in the current case.

By Barbara Jungwirth