Tags: Health Topics | hiv | aids | smallpox | immune system

HIV Destroys Smallpox Immunity

a vial of smallpox vaccine
A vial of smallpox vaccine (J. Scott Applewhite/AP)

Friday, 10 January 2020 10:36 AM

HIV infection causes a loss of immunity to smallpox, even in people who were vaccinated as kids and are taking antiretroviral drugs to restore their immune system, a new study finds.

Such "HIV-associated immune amnesia" could explain why people with HIV who are on antiretroviral therapy still have shorter lives on average than people without HIV, according to the researchers.

The new study included 100 HIV-positive and HIV-negative women who were vaccinated against smallpox in their youth. Their blood was exposed to the vaccinia virus, which is used in the smallpox vaccine, in order to assess T-cell and antibody responses.

Smallpox was chosen because the last known U.S. case was in 1949, so participants couldn't have had recent exposure to the virus, which would have triggered new immune responses.

Normally, a person vaccinated against smallpox has CD4 T-cells that remember the virus and respond in large numbers when the person is exposed to it again. But the immune systems of HIV-positive women on antiretroviral therapy had a limited response to the vaccinia virus.

Antiretroviral therapy works by boosting CD4 T-cell counts in people with HIV. These findings suggest that while antiretroviral therapy may increase total T-cell counts, it can't recover virus-specific T-cells created by childhood vaccinations, said study leader Mark Slifka. He's a professor of molecular microbiology and immunology at Oregon Health and Science University School of Medicine, in Portland.

The study was recently published in the Journal of Infectious Diseases.

The researchers now plan to evaluate whether the loss of smallpox immunity also occurs in HIV-infected men, and if people with HIV also lose immune memory to other diseases.

Other recent studies found that the immune systems of children who contracted measles similarly "forgot" their immunity against other illnesses, such as the flu.

© HealthDay

   
1Like our page
2Share
Health-News
HIV infection causes a loss of immunity to smallpox, even in people who were vaccinated as kids and are taking antiretroviral drugs to restore their immune system, a new study finds.
hiv, aids, smallpox, immune system
294
2020-36-10
Friday, 10 January 2020 10:36 AM
Newsmax Media, Inc.
 

The information presented on this website is not intended as specific medical advice and is not a substitute for professional medical treatment or diagnosis. Read Newsmax Terms and Conditions of Service.

Newsmax, Moneynews, Newsmax Health, and Independent. American. are registered trademarks of Newsmax Media, Inc. Newsmax TV, and Newsmax World are trademarks of Newsmax Media, Inc.

NEWSMAX.COM
© Newsmax Media, Inc.
All Rights Reserved