Dutch company tested new TB-vaccine on 2,800 black babies

Posted on | juni 2, 2011 | No Comments

picture of South African infant: Red Cross Children's Hospital

The first phase of a trial to test the efficacy of a tuberculosis (TB) booster shot for babies has been completed in April 2011, with nearly 2,800 infants participating in the two-year trial, in which researchers from the South African Tuberculosis Vaccine Initiative (SATVI) hope to prove that their new vaccine can act as a booster shot to improve the efficacy of the only existing inoculation against TB: the 90-year-old Bacille Calmette-Guerin (BCG) vaccine. This is seenn to be growing increasingly resistant to the new strains of drug-resistant tuberculosis in South Africa – especially on HIV-positive infants.

The carer of each baby participating in the trial was paid R150 (US$15) per clinic visit. “This provides an incentive,” said Linda Sibeko, who lives in Worcester and is a member of this study’s interim community advisory board. “However parents also saw it as a way of learning more about TB. People are welcoming it. We explained … and now everyone wants to be involved.”

Dutch biopharmaceutical company Crucell N.V. and the Aeras Global TB Vaccine Foundation announced the start of their clinical trials in infants of the jointly developed tuberculosis (TB) vaccine candidate, AERAS-402/Crucell Ad35.

This was the world’s first-ever clinical trial designed to test this vaccine candidate in infants – despite the fact that human babies cannot give their ‘informed consent’ to participate in such medical experiements.

The claim is made that the AERAS-402/Crucell Ad35 vaccine candidate used on the babies was previously tested for safety in healthy adults in the United States and South Africa, and also in adults exposed to TB in South Africa and Kenya.

Current BCG vaccine does not protect against lung-TB
The 90-year-old BCG TB-vaccine has over the years become a standard part of national immunisation programmes in many countries, including in South Africa, but it does not guarantee protection against the most common form of TB, which attacks the lungs. An effective TB vaccine could help save some of the two million people who die annually from the disease, a quarter of whom are co-infected with HIV, Irin news writes. The vast majority of patients dying of the incurable form of the bacterial disease, extremely-drug-resistant Tuberculosis, live in South Africa.

First time infants are used as guinea-pigs in TB-drug trial
The vaccine has thus far been tested in HIV-infected adults in South Africa, the UK and Senegal, but because this will be the first test in infants – and only healthy, i.e. HIV-negative infants were enrolled.

According to Michele Tameris, study manager for the trial, the vaccine has already been administered to infants in Gambia, “with no side-effects other than a brief period of mild discomfort, and the irritation and swelling at the injection site usually associated with childhood immunisations.”

Dr Glenda Grey, co-director of the Perinatal HIV Research Unit at Witwatersrand University, which participated in South Africa’s first human clinical trial for an HIV vaccine in 2003, said oversight bodies “demanded a higher burden of proof when children and infants were included in studies.

“Ethics committees must also ensure that infants don’t find themselves in a more vulnerable position than they already are because they participated in a trial; you have to minimise the harm and maximise the benefits,” she said. You have to make sure the parents or caregivers understand the … risks and benefits …and that their child is contributing to science..’

“Does a child benefit from being in the study? They often do. The nice thing … [is that] any illness is diagnosed much earlier and [they] get treatment, whereas … [other children] may not be able to get to a clinic, may be misdiagnosed or get poor treatment,” said Grey.

Consent is always a crucial issue. “You also have to make sure the parents or caregivers understand the informed-consent process, the risks and benefits, that a vaccine may or may not work, and that their child is contributing to science.”

Ethics in practice The town of Worcester, in the winelands of Western Cape Province, is one of three towns participating in the SATVI trial. This town has the dubious honour of having the highest concentration of residents co-infected with HIV/AIDS and Tuberculosis. These co-infections have also been the most important cause of ‘premature death “in the province since 2007, Tameris said.

“The blood samples taken in this study would be much smaller, and would also be taken less often, because drawing adult-sized samples from pint-sized participants could mean risking anaemia or other illnesses. You have to work out the absolute minimum sample you need, down to microlitres. Babies are very sweet and cute, but it’s not always easy when they become distressed and resent having to be held tightly to have blood taken,” she said.

‘Blessing in disguise’
The South African Department of Health estimated that almost 90 percent of children under the age of one were immunised with the old TB vaccine in 2008. “We have very high immunisation rates in South Africa so we have a culture of immunising our children and, in that sense, vaccine trials are easier and more understandable than drug trials to many people,” Grey noted.

Although there have been concerns that the legally mandated R150 (US$19) given to participants per clinic visit could provide a (financial) incentive, Linda Sibeko, who lives in Worcester and is a member of the study’s interim community advisory board, said parents saw it as a way of learning more about TB. “People are welcoming it. We explained … and now everyone wants to be involved.”

AUTHOR: Adriana Stuijt
URL: http://censorbugbear.blogspot.com
E-MAIL: a.j.stuijt [at] knid.nl


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