Publication Q&A: BCG Vaccination and Mother-to-Infant Transmission of HIV
November 2019 – Matthew Wood shares insights from a recent publication in The Journal of Infectious Disease with contributing authors from the Sodora Lab at the Center for Global Infectious Disease Research (CGIDR).
BCG Vaccination of Mother-to-Infant Transmission of HIV
Matthew P Wood, Lianna F Wood, Megan Templeton, Bridget Fisher, Adriana Lippy, Chloe I Jones, Cecilia S Lindestam Arlehamn, Alessandro Sette, James T Fuller, Patience Murapa, Heather B Jaspan, Deborah H Fuller, Donald L Sodora
Published in The Journal of Infectious Disease Research, October 2019
What is your lab’s current research focus?
Our lab is focused on two principal areas of HIV research: HIV transmission and HIV-induced disease and immune factors that impact progression to AIDS. Collectively, these research strategies are designed to produce novel vaccine approaches and immune therapies that will decrease the spread of HIV and/or prevent disease progression in HIV-infected people.
What is the significance of the findings of this publication?
Infants born to HIV-infected mothers have a 15% – 45% risk of becoming infected. In 2017, 180,000 new cases of HIV were reported in children born to HIV infected mothers worldwide. Increased levels of activated CD4 T cells, a type of cell that HIV can easily infect and replicate in, is associated with a greater risk of becoming infected with HIV. Routine administration of the tuberculosis vaccine Bacillus Calmette Guerín (BCG) has been associated with increased levels of activated CD4 T cells in infants born to HIV-infected mothers, thus suggesting that BCG may increase the risk of infants acquiring HIV from their mothers. This transmission of HIV following birth primarily occurs during breastfeeding.
Our study used a non-human primate model of oral SIV transmission to simulate human infant HIV infection during breastfeeding. This model can also be vaccinated with BCG, and responds similarly to humans. Our results indicate that while BCG induces several immunological changes, including increasing the levels of activated CD4 T cells, we did not observe any change in the risk of SIV transmission nor in several measurements of disease severity. This finding therefore suggests that the immunological changes associated with BCG vaccination do not present a risk in terms of HIV acquisition or HIV disease severity.
What are the next steps for this research?
While BCG did not influence the progression to AIDS in the non-human primate model, experiments are currently underway to explore factors that did increase SIV disease severity. This work is important considering that HIV often leads to rapid progression to AIDS in infant humans.
Seattle Children’s CGIDR contributing authors: