Thursday, 12 May 2011

Editorial: Twelfth of May 2011

Concerning another monkey vaccine

Two news stories appear to coincide with managing the scourge of HIV/AIDS, on the one hand is the study of eradicating the primate variant of HIV known as the Simian Immunodeficiency Virus (SIV) in rhesus macaques making use of a genetically modified version of the rhesus cytomegalovirus (CMV).

The good news here is that this vaccine appears to strengthen the immune system to the point of controlling SIV and eventually reducing its progressive infective rate until the disease is abated.

However, there are many concerns with this study from the controversial view that patient zero contracted HIV from a chimpanzee to the concerns of introducing a strain of human CMV as part of a treatment regime.

Africans may not benefit

CMV belongs to the herpes family of viruses that is usually benign or dormant but can break out as chicken-pox, shingles, fever blisters (herpes I) or genital herpes (herpes II) amongst others, it is more prevalent in sub-Saharan Africa than anywhere else making that line of research rather risky and ethically questionable in terms of safety and assurances for effectiveness.

This study might well be of greater value to those outside sub-Saharan Africa but after the failures of a number of vaccine trials, many of which were aborted too, it is important to remain vigilant that all checks, procedures and monitoring are in place so as not to raise false hopes at first and then cajole subjects into trials that might be of greater detriment to their already weak health status.

Helping sero-discodant couples thrive

Accepting the fact of the prevalence of HIV/AIDS has been hard enough for some societies and beyond that the measures needed to prevent infection are fraught with cultural, religious, political, social and economic issues.

UNAIDS have released a study that heralds the reduction of infection between partners where one is HIV infected or in the jargon, sero-discordant couples. The study began with about 1,750 couples from 8 countries in Asia, Africa and South America.

Entry into the study required the infected party have a CD4 count of between 350 & 550 which represents a level at which the WHO does not require the patient to have commenced Anti-RetroViral (ARV) treatment.

Between news and scientific fact

One arm of the study was immediately entered into ARV treatment on commencement of the study and the other arm only commence treatment after two consecutive tests measured a CD4 count regression to between 200 & 250 or had developed an AIDS-defining illness.

The results show a reduction in transmission of HIV infection in 96% of the cases as reported by UNAIDS but the news story does not appear to comment on the significance of viral loads which is the amount of virus in the blood that could determine how infectious a person can be.

It is however known that ARV does reduce the viral load significantly to somewhat undetectable levels it does not however mean the complete absence of contagion.

Subtle observations with this study

The study that took in couples from the United States was aborted and though it was supposed to run for 78 months seems to have ended 3-4 years early because of the positive results though one should be concerned about the fact that low viral loads and higher CD4 counts for the time of that study does not confer immunity by any stretch of the imagination.

The lack of Western subjects is also instructive because medication in the study did not include multi-class combination drugs like Atripla though combinations of other discrete drugs would have been effective all the same.

At the same time, it is possible that Eastern Europe might have benefitted from this study though on balance the cases of heterosexual HIV infection would have been more prevalent in the areas that had the study.

HIV is more than a medical condition

It is important that the kind of complacency that appears to attend to HIV infection in the West because of more effective treatments does not cascade to these other study areas that included India, Brazil, Thailand, Malawi, Zimbabwe and South Africa, the absence of Nigeria from that study group should be investigated too.

On the whole, the progress in trying to control, manage or cure HIV is welcome but the news stories appear to herald situations which on closer scrutiny of the facts belies less of the optimism being communicated.

Most importantly, there are significant anthropological consequences of these studies between countries, cultures, traditions and laws coming north of the equator in Africa would have given this study much more empirical import just as allowing it to include the West, China, Russia and Eastern Europe. HIV in different societies is a lot more than a medical condition even in the broadest terms.

Acknowledgements

The following sources form the basis of this editorial; the news about the CMV vaccine against SIV was published by the BBC then related to drug regimes reducing HIV transmission as published by UNAIDS but 6 months earlier, the BBC had run a similar story.

The HIV Prevention Trials Network (HPTN) Study is fully documented at the HPTN 052 website. Meanwhile the list of available drugs for the treatment of HIV as at February 2011 is hosted at the AIDSMeds website. Regarding CMV the New York Department of Health offers some information about the Cytomegalovirus.

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