TB vaccine can be a killer for babies with HIV

Nov 4 2007

Experts in South Africa say a vaccine which was meant to protect children in developing countries from tuberculosis (TB)may in fact be killing them.

They say the BCG vaccine (Bacille Calmette-Guerin) which is produced by using a bovine version of tuberculosis, is causing serious infections in some babies and young children who are HIV-infected.

Dr. Mark Cotton, a pediatrician and HIV researcher at Stellenbosch University in South Africa says some research has indicated that there was a 75-percent mortality rate in children with BCG disease, and 70 percent of those children were HIV-infected.

Dr. Cotton says this is a problem which needs immediate attention.

In a report issued by The Forum for Collaborative HIV Research, the health emergency caused globally by the double whammy of HIV and TB is starkly highlighted.

According to the report tuberculosis has made a global comeback because the AIDS virus, by destroying the immune system, has opened the door to what is usually a latent infection.

The report says the nucleus for the spread of TB is in sub-Saharan Africa, where half of all new TB cases are HIV co-infected, and this is where drug-resistant TB is silently spreading.

TB once activated, can quickly kill victims and Veronica Miller, director of the independent global group says it is happening now but the science and coordination needed to stop it are insufficient.

The Forum for Collaborative HIV Research is a group which includes researchers, patient advocates,government and industry.

HIV now affects an estimated 40 million people worldwide, there is no cure and when untreated, it decimates the immune system leaving victims vulnerable to a plethora of infections including TB.

Experts say one-third of the world's population is now infected with TB and without effective treatment, 90 percent of people infected with both HIV and TB die within months.

TB only becomes an active infection in one out of 10 people over a lifetime, however 10 percent of HIV patients who also have TB develop activated tuberculosis every year.

The BCG vaccine is usually given at birth but as it uses a live microbe, in those with weakened immune systems it can itself cause disease.

According to Dr. Cotton an estimated 400 per 100,000 HIV-infected infants in the Western Cape of South Africa had become sick from the BCG vaccine.

Babies are not tested for HIV infection until about 6 weeks of age, meaning many infants are unknowingly being given a vaccine that is dangerous for them.

This delay in the diagnosis of HIV means a delay in the access to antiretroviral therapy and serves to compound an already complex situation.

Dr. Cotton says it may be possible to simply vaccinate children with BCG after it is known whether they are HIV-infected but he says such changes interfere with programs and complicate the issue thus creating a dilemma.

The best solution he says would be to have earlier diagnosis and treatment of HIV, then children infected with HIV can be given the antibiotic, isoniazid, to prevent TB infection.

Health experts suggest that too little is known about tuberculosis and HIV to effectively halt the ravage of the diseases across the African continent.