Vaccinate Immigrants Immediately on Arrival? Not So Fast

The U.S. policy that calls for giving all recommended vaccines to new immigrants as soon as they step off the metaphorical boat may need a tweak, said researchers who reported a fatal outcome for one teenage girl.

The 17-year-old from Central America entered the U.S. in the fall of 2019 without documentation and was placed in a detention center where, as dictated by federal policy, she quickly received the full CDC list of “catch-up” vaccines, according to Jamie L. Stokke, MD, of Children’s Hospital of Los Angeles, and colleagues writing in the New England Journal of Medicine.

This was then followed by a physical exam that revealed a lump on her neck, and chest x-rays showed a mediastinal mass. She was diagnosed with nodular sclerosing Hodgkin’s lymphoma and began ABVE-PC chemotherapy. It did not go well, the researchers explained, with a host of complications including febrile neutropenia, varicella zoster infection, abdominal pain, periodic rashes, and trouble breathing. Two months after the girl’s arrival in the U.S., the febrile neutropenia worsened enough to require hospital admission.

At that point, her doctors performed an “extensive infectious workup” that turned up nothing, Stokke and colleagues said. Lesions developed on her liver and spleen and her lung function deteriorated. About 1 month after admission, she died from respiratory failure.

The root problem was finally discovered at autopsy: disseminated measles infection. Among the vaccines she’d received on entry was the measles-mumps-rubella (MMR) product. Molecular analysis of the measles virus isolates confirmed that it was the vaccine strain. “No evidence of secondary infection or active lymphoma was found,” the investigators wrote.

This appears to have been the first measles death in the U.S. since 2015.

However, it doesn’t mean the practice of ensuring that new immigrants are vaccinated should be halted, Stokke and colleagues emphasized: “This unfortunate outcome is extremely rare and should not diminish the importance of routine and timely vaccination to minimize community spread.”

It does suggest, though, that first determining their overall health status would be a good idea. Most live-pathogen immunizations, including MMR, are contraindicated for individuals with many primary and secondary immunodeficiencies. Thus, Stokke and colleagues recommended that immigrants undergo “screening for new or preexisting conditions that can cause profound immunocompromised status before administration of live vaccines such as the MMR vaccine.”

In addition, clinicians looking to unravel mysterious infections in immunocompromised patients should consider that vaccines might be the cause, they noted.