News Release
October 10, 2024
Among people with HIV, mpox vaccine protects well
Long-awaited effectiveness data comes from a study of nearly 20,000 U.S. patients. Unfortunately the vaccine is in short supply.
After the mpox virus reemerged globally in 2022, people with HIV were identified as facing disproportionately higher risk and more severe consequences of infection. Doctors and public health specialists urged members of that population to pursue getting a smallpox vaccine thought to be effective against mpox, though little efficacy data existed for that use.
That changed this week. Research published in the journal Clinical Infectious Diseases indicates that vaccination against mpox is highly protective among people with HIV.
“In our cohort, we saw 84% protection overall after one or more vaccines, which means vaccination averted almost nine out of 10 cases that would have occurred,” said Dr. Rachel Bender Ignacio, the paper’s senior author and an associate professor of medicine at the University of Washington (UW) School of Medicine. “Although getting mpox after receiving both doses does occur rarely, we observed no such cases. That means that getting both recommended doses is highly protective.”
The study was led by researchers at Center for AIDS Research (CFAR), a joint program of the UW and the Fred Hutch Cancer Center in Seattle.
The investigators examined data from 19,777 people with HIV who received care at nine CFAR-linked clinic systems across the United States. Data collection spanned Jan. 1, 2022, through May 31, 2023. In the cohort, 413 cases of mpox occurred, translating to an infection rate of 2.2 per 100 person-years. This is a much higher figure than has ever been documented globally, Bender Ignacio noted.
The researchers had access to patient data such as the presence of antiretroviral therapy, detectable viral load, and dates of vaccines and mpox diagnoses.
“The data gave us a unique opportunity to answer questions about what outcomes people with HIV experience if they acquire mpox, and also how effective the vaccine is in this population,” said Michalina Montaño, an epidemiologist in Fred Hutch’s Vaccine and Infectious Diseases Division. She was the paper’s lead author.
In calculating vaccine effectiveness across their cohort, the researchers counted only the cases in which patients received at least one dose 14 or more days before their diagnosis.
Estimates of mpox vaccine effectiveness in the general population have ranged from 65% to 85%. “It's really encouraging that, among people with HIV, we're at the high end of that range, even when some people had only received one of the two recommended doses,” Montaño said.
Antiretroviral therapy, which can restore much of the immune-system potency that HIV impairs, appeared protective against mpox’s harshest symptoms.
“The people who were not on medication or not taking their medication consistently were at highest risk of being hospitalized from mpox,” she said.
The upbeat finding of vaccine effectiveness, however, is tempered by the lack of vaccine availability, particularly in Africa, where incidence of both mpox and HIV are highest in the world.
“Even worse in this epidemic, especially with this new clade (variant) of mpox virus that’s now affecting people in Central Africa, is that it’s barely being resourced with drug-treatment availability and vaccine availability,” said Bender Ignacio. “We need to be aware that, in addition to children, people with HIV might get more seriously ill with mpox, and should be prioritized for vaccination.”
She noted too that, as with the COVID-19 vaccine supplies during that pandemic, access to mpox vaccine has seemed to shift away from resource-poor nations and toward wealthier Western nations.
Mpox typically is transmitted via kissing, sex or touching an infected person’s rash or items that have contacted the rash, such as a towel or bedding. In the United States, most mpox cases emerge among men who have sex with men.
“The risk of severe disease from mpox is quite high in communities where people are highly immunosuppressed, either because of HIV or malnutrition, or their immune systems are untrained, as with young children in Central Africa, or poor such that many live in close quarters,” said coauthor Dr. Adrienne Shapiro, a UW Medicine infectious-diseases specialist and global health researcher.
“It should be reassuring that the data from this paper shows that vaccines are incredibly effective,” she added, “so we can be very targeted about putting effort into getting these highly effective vaccines to people who need them the most.”
The research was supported by funding from the National Institute of Allergy and Infectious Diseases (R24 AI067039, P30 AI027757). The authors’ conflict-of-interest statements are available in the paper.
For details about UW Medicine, please visit http://uwmedicine.org/about.
Contact:
Brian Donohue
206-543-7856
bdonohue@uw.edu
Duke University
Source: UW Medicine - University of Washington
https://newsroom.uw.edu/news-releases/among-people-with-hiv-mpox-vaccine-protects-well
"Reproduced with permission - UW Medicine - University of Washington"
UW Medicine - University of Washington
For more HIV and AIDS News visit...
Positively Positive - Living with HIV/AIDS:
HIV/AIDS News
|
