bioethics: Case Discussion 2

["Ishrat Waheed" <biotronics1@hotmail.com>]

>>The issue at hand is both exhilarating and sobering at the same time. The 
>>two candidate HIV vaccines (clad C.VEE and HIVA.MVA) are novel vector 
>>based vaccines that induce cellular immunity against HIV subtypes C and 
>>A.  Vector based vaccines are becoming popular for long term immunization 
>>against other pathogens as well, i.e., rubella.
>>
>>Unfortunately, they are only protective and not curative and even in that 
>>scenario, their response rate is never 100%.  <?xml:namespace prefix = o 
>>ns = "urn:schemas-microsoft-com:office:office" />
>>
>>HIVC.VEE and HIVA.MVA have been tested for safety and immunogenicity in 
>>the countries of their origin.  Their trial in areas of high HIV 
>>prevalence is a natural step towards looking at their efficacy in cross 
>>reacting strains, however, when considering pregnant women as trial 
>>subjects, the long term safety and efficacy of the vaccine in both the 
>>adults and the newborn have to be considered
>>
>>
>>
>>Answers to the Qs:
>>
>>Ø      Can the decision to place all HIV trials on hold be defended by 
>>the DRA given that the safety had been already been demonstrated and the 
>>immunogenicity in the East African Setting was an issue of international 
>>importance?
>>
>>
>>
>>   1-  The decision to put all HIV/AIDS trials on hold by the DRA is a 
>> sound one.  For once, the ethics committee should be lauded for its 
>> conscientious efforts to bring a reform in the trial protocols in the 
>> developing countries with high AIDS prevalence.  Although, the UNAIDS 
>> guidelines on the issue of the primary healthcare provisions during 
>> clinical trials in the developing countries are fairly lax, it is the 
>> responsibility of the local DRA to intervene in the best of their public 
>> interest especially when conducting trials in pregnant women.
>>
>>     Although the safety and immunogenicity issues had been addressed 
>> during the safety trials, the real life situation in high HIV prevalence 
>> cannot not be completely addressed without taking into account 
>> antiretroviral therapy regimens. Should such volunteers (especially 
>> pregnant women) become infected with HIV/AIDS during the course of 
>> vaccine trials, HAART becomes a must in order to save the 
>> child  Following possibilities come to mind:
>>
>>1-     Volunteers vaccinated with clad C or clad A vaccines could still 
>>get infected with other less frequent strains (B, D, E, F) that do not 
>>cross react with A or C antigens.
>>
>>2-     In high clad C areas, long term (7-10 yrs.) protection offered by 
>>these novel vector based vaccine (especially the HIVA.MVA) cannot be 
>>extrapolated from safety studies conducted in non-African settings.
>>
>>3-     In pregnant mothers, such vaccines may not protect the fetus from 
>>developing a latent HIV infection during gestation due to lack of 
>>well-developed immune system at that stage.
>>
>>4-     Test subjects infected during the trial may provide an additional 
>>study group for the study of efficacy of these vaccines in combination 
>>with antiretroviral therapy.
>>
>>
>>
>>Ø  Was the hold related to risk-benefit decisions made in industrialized 
>>countries? If so, were these decisions relevant for the situation in the 
>>East African country.
>>
>>
>>
>>Yes, in my opinion, the hold was primarily due to the concern over 
>>potential safety risk to the fetus/newly born from these experimental 
>>vaccines.  This concern was duly addressed by the courts and the govt. 
>>healthcare bodies by approving antiretroviral treatment to all pregnant 
>>women.  The risk/benefit decision on providing the long-term 
>>anti-retroviral therapy to volunteers in the developed countries, should 
>>be applicable to volunteers in any other parts of the world just the same.
>>
>>Sincerely,
>>
>>Ishrat Waheed, MPhil, PhD
>>
>>
>>
>>
>> >
>
>
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