What you need to know:
- 40 infants have so far been involved in the Aids prevention trials which started two months ago at Kenyatta National Hospital and the results of the study are expected in June 2012
The first Kenyan infants to take part in an Aids vaccine trial have been vaccinated and are being observed to see how their immune systems respond to a new formula that has excited the global science community.
Doctors at the Kenya Aids Vaccine Initiative (Kavi) are conducting a study on the vaccine that is billed to have the most advanced vaccine design ever tested.
Forty infants have so far been involved in the Aids vaccine trials, which started two months ago, and the results of the trials are expected in June 2012.
Of those vaccinated so far, 20 received the Aids vaccine plus other vaccines normally administered to infants, while another 20 in the control group received the usual vaccines without the Aids vaccine.
The infants, the youngest volunteers to an HIV vaccine trial in the country, will provide crucial data on whether the Aids vaccine, if proved effective, produces better results when given to a person at infant stage. The babies will also provide data on the vaccine’s safety in newborns.
If the vaccine, known as Modified Vaccine Ankara (MVA), is proved to be effective in subsequent clinical trials, it is going to be given to all children after birth, the same way infants are given anti-tuberculosis vaccines at birth.
According to Prof Walter Jaoko, the vaccine’s principal investigator, no adverse reaction has been recorded since the first baby got the vaccine.
“In all the children who have been vaccinated, the vaccine has proved to be safe,” said Prof Jaoko.
“The reason we settled on this MVA vaccine is because of its excellent safety record in past trials involving adults in the USA, UK, Rwanda, Uganda and Kenya.”
The babies were vaccinated when they were five months old, the age researchers have determined as the best time to introduce the vaccine in infants. In total, the researchers are expected to involve 72 babies.
Half of these babies will be vaccinated with the MVA vaccine while the other half (the control group) is to receive the usual baby vaccines.
Each baby will be followed for one year from the date of vaccination to monitor their immune response upon introduction of the vaccine. This response is measured by looking at the cellular immune response specific to HIV. This is where cells of the immune system kill cells that have been infected.
The study is also going to determine the interaction of the Aids vaccine with other vaccines such as DPT, tetanus, pneumonia and flu that are routinely given to babies before they celebrate their first birthday.
Parents who have agreed to have their babies participate in the study were recruited through the Kenyatta National Hospital’s antenatal clinic.
Sensitivity of the tests
Due to the sensitivity of the tests, Prof Jaoko says they have had many sessions with the parents before the babies were recruited into the programme.
“Unlike the adult volunteers who participated in our earlier Aids vaccine trials, we have had many educative and counselling sessions with parents of these babies.”
Baby volunteers, notes Prof Jaoko, are a very sensitive group, hence the need to reassure their parents that all is well as the vaccine cannot cause HIV infection.
The researchers have had to seek the consent of both the baby’s mother and father.
“This is a very delicate study and the volunteer is a person who cannot consent on his or her own. That is why we insist both parents consent to the trial to pre-empt future complications with one parent, especially the father, dissociating himself from the trials,” explained Prof Jaoko, who is also the acting dean at the University of Nairobi’s School of Medicine.
The study was cleared by the Kenyatta National Hospital and University of Nairobi Ethical Board, which is mandated by the government to rigorously assess and then clear or reject any studies involving human beings.
One of the key responsibilities of the Board is to protect the wellbeing of those who participate in such clinical trials and to take action against researchers for any violations. Research guidelines allow minors to participate in research only after an adult, either a parent or guardian, consents on their behalf.
In Kavi trials, those participating in the programme are HIV-negative babies, through whom the researchers want to find out if the vaccine is able to initiate a defensive mechanism in the body.
“This is an HIV preventive vaccine and, at this stage, what we are trying to find out is if the vaccine will produce the right amount of immune response necessary to prevent HIV infection,” says Prof Jaoko.
The babies participating in the trials have been divided into two groups – those who are breastfed and non-breastfed ones.
Each of these groups have further been divided into two other groups. One arm of the breastfed babies will get both the Aids vaccine and the other the usual vaccines while the other arm will be the control group and will not get the HIV vaccine. The formula-fed or non-breastfed babies will also be divided into the two arms.
The reason for designing the study like this, explains Prof Jaoko, is to find out the performance of the vaccine in breastfed and non-breastfed babies. It is also intended to compare the immune response in babies who receive the HIV preventive vaccine along with other vaccines, to the response in those who receive the usual vaccines minus the HIV one.
“If the data indicate there is good immune response, we shall move to the second stage where we shall do trials on another vaccine that is to be combined by the MVA,” says Prof Jaoko.
Kavi started recruiting the babies early last year and, so far, parents of 90 babies have agreed to have their infants volunteer for the trials.
Researchers are now screening these babies to see who among them qualifies for the study.
Only those babies who are HIV negative, have appropriate weight and no health complications are selected to participate in the trials.
Besides Kenya, Gambia, too, is about to start conducting Aids vaccine trials in infants.
Uganda was one of the first countries in Africa to carry out an Aids vaccine trial in babies. Although the vaccine was found to be safe, it failed to generate a sufficient amount of immune response.
A number of studies done in America, Asia and Europe have shown some encouraging responses in infants who received an HIV vaccine, but not to the degree of response seen in adults. One of the reasons for this is infants’ rapidly developing immune system.