According to the results published yesterday in the Journal of Infectious Diseases by Spanish researchers at Barcelona’s Hospital Clinic, this type of therapeutic vaccine helps the patients who are carriers of the virus, combat infection and control the appearance of AIDS in the same way as with the current ARV treatments.
The researchers say the final aim of the therapeutic vaccines will be to avoid a life-long treatment with ARV drugs. According to the National Agency for the Control of AIDS (NACA), at least 350,000 persons living with HIV/AIDS in Nigeria are receiving free ARV treatment.
The research team on “Infectious Diseases and AIDS” led by Dr. Josep Maria Gastell from IDIBAPS – Hospital Clinic, Barcelona, Spain, has developed the vaccine, using the brand HIVACAT, a model of the therapeutic vaccine based on the patient’s own dendritic cells (are immune cells forming part of the mammalian immune system). This reduction in the viral load is, though, still considered to be insufficient, is the first therapeutic vaccine, which has achieved a positive response in the majority of patients.
Reacting to the new finding, the Director General of NACA, Prof. John Idoko, said: “This was an extremely small scale study, so it is important to recognise that there is a long way to go before drawing any conclusion from this research.
“However, as HIV treatment has evolved hugely over the past 10 years, we always welcome new research, which sheds new light on effective treatment options for people living with HIV.
“Therapeutic vaccines are an exciting area of research. Current drug treatment is good at keeping HIV in check, but as people with HIV now routinely live well into old age, the lifetime cost of treatment can be high. An effective therapeutic vaccine could not only be less expensive, but people living with HIV might find it easier to manage.
“This trial is a step in the right direction, but until we find a vaccine that controls the virus as well as ARV treatment does, we are not there yet. This research gives us a good idea of where to concentrate efforts in the future.”
According to the study, a total of 24 patients participated in this double blind clinical trial, half of them formed the control group of those who did not receive the vaccine. None of these patients received antiretroviral treatment, and to enter into the study they had to maintain a good Tlymphatic blood load (>450 per mm3).
The vaccine was made from each person’s own dendritic cells, a special type of cell that is a key regulator of the immune system. The cells were extracted and “re-educated” to attack the virus, using samples of HIV also taken from individual patients.
The adjusted cells were then injected back into them in three stages, two weeks apart. The vaccine was administered in three doses with an interval of two weeks between each one.
The researchers concluded: “At the end of 24 weeks, it showed that the majority of the patients had experienced a significant decrease in the viral load. This decrease was very significant in some of them, but in no case did the virus become undetectable.
“However, this is a very important improvement with respect to previous initiatives where, with a similar vaccine, there was a modest response in 30 per cent of the treated patients. No therapeutic vaccine has achieved, up to now, the same level of response as in this study. A new clinical trial is underway testing the administration of the vaccine in conjunction with antiretroviral drugs to allow an improvement in the results.”
The researchers said the principal objective of therapeutic vaccines is to minimise the need for antiretroviral drug treatment. They added: “These treatments have improved enormously over the past few years and have become easy drugs to administer with few side effects. Although the daily administration is not ideal, there is no experience over the long term and it is not known if the treatment could bring about resistance.
“It aims to deal with the treatment of chronic patients for their whole life, which currently is an important economic burden for the health system. The annual budget for ARVs in Hospital Clinic is around €30 million. Furthermore, the therapeutic vaccine is easy to produce and small administrations could be implemented in developing countries, too. To undertake this ambitious objective, there has to be a continuing scientific and economic efforts in initiatives such as HIVACAT.”