Immunologic Basis for Revaccination of HIV-infected Children Receiving HAART
This article is an interesting discussion of potential public health surrounding HIV positive children and immunizations. Untreated HIV reduces the ability of a child’s immune system to respond to infections and vaccines. As the mortality rate decreases, there is a growing need to understand how HAART affects immunity to vaccine preventable infections, with the goal to improve individual and public health. Studies have demonstrated that immune reconstitution following HAART mirrors that of the immune system over the individual life span. Young children with few memory cells will reconstitute with naïve T cells. Adolescents or young adults will reconstitute with a combination of naïve T cells and memory T cell expansion. Older adults will reconstitute with the expansion of memory T cells. When a child is infected perinatally it is believed this predisposes the immune system towards effector T cells.
The authors use the measles virus as a model to study immunological memory. Exposure to measles generally results in lifelong protective IgG antibody levels. When a child is HIV infected there are typically low levels of immunity seen in response to vaccines given prior to initiation of HAART. Studies with Zambian and Thai children have shown a decrease in immunity levels over time, producing a group of measles susceptible children. Determination of the optimal time to revaccinate HIV positive children is not yet clear but emerging data suggests that children who respond to HAART may successfully be revaccinated when CD4 cells return to normal levels for age.
Rainwater-Lovett, K. & Moss, W. J. (2011). Immunologic basis for revaccination of HIV-infected Children receiving HAART. Future Virology, 6(1), 59-71.
When I read this article the first thought that came to my mind was whether or not those suffering with HIV/AIDS could even afford both highly active anti-retroviral treatment as well as lifelong vaccinations for various diseases. Unfortunately poverty and HIV/AIDS are linked together. 68% of those with HIV live in sub-saharan Africa, the poorest region of the world. Americans who are also living in great poverty are 5 times more likely to have HIV than the average American. Also the cost-effectiveness of HAART in the first place must be examined. HIV prevention has been shown to be 28 times more cost-effective when compared to HAART.
ReplyDeleteIt would have also been beneficial if the authors discussed the fact that these children are very likely to eventually be infected with tuberculosis. Throughout the world 75% of people with HIV also have TB. Therefore I am curious if the BCG vaccine for tuberculosis is the main vaccine that these children will be receiving. If HIV positive children are more likely to nullify the effectiveness of the BCG vaccine then that could have serious worldwide consequences.
1. HIV prevention before HAART in sub-Saharan Africa.
Marseille E, Hofmann PB, Kahn JG.
Source
Institute for Health Policy Studies, Center for AIDS Prevention Studies, and AIDS Research Institute, University of California, San Francisco, Box 0936, San Francisco CA 94143, USA. http://www.ncbi.nlm.nih.gov/pubmed/12044394
2. http://www.unmillenniumproject.org/resources/fastfacts_e.htm
3. http://articles.latimes.com/2010/jul/20/science/la-sci-aids-poverty-20100720
4. http://www.avert.org/worldstats.htm
5. Poverty and HIV/AIDS in South Africa: an empirical contribution
Very interesting topic considering that vaccination even in healthy children is so controversial this day in age. This article mentions that starting HAART before vaccination could preserve immunity to certain diseases prevented through vaccines.
ReplyDeletehttp://www.medicalnewstoday.com/articles/199651.php