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Rocky Mountain Spotted Fever. Schistosomiasis Bilharzia. Tickborne Diseases. Tuberculosis Drugs. West Nile Virus. Addressing Zika Virus. Types of Funding Opportunities. See Funded Projects. There have been multiple attempts before now but many were found to be unsafe and most failed to demonstrate a hint of effectiveness — two studies evaluating adenovirus type-5 vectored vaccines for HIV Ad5 in the s were found to actually increase the risk of HIV infection.
With this type of vaccine, a piece of messenger RNA that codes for a part of the virus, in this case HIV, is enfolded into a vector. Based on that protein, the immune system is then trained to recognise the virus so that when it encounters it, it rallies to attack it. Over the years, HIV has mutated into numerous variants. Another possible benefit of the mRNA approach is that it is viewed as easily modifiable, meaning it could have an edge over other vaccine techniques.
Related News I-Mab doses first subject in solid tumour therapy trial in China. News Repligen begins Phase 1 study of RG Content from our partners Why this global life sciences COO believes relocation to Charleston, SC, was key to achieving next-level success. Some have suggested that interest in an HIV vaccine that only reduces viral load set point without preventing acquisition of infection is declining simply because of the increased focus on combining newly developed nonvaccine prevention modalities.
But access and adherence to individually targeted prevention measures for everyone at risk of infection remain seriously limited. Without an expensive and difficult to sustain global effort, large numbers of people will continue to become infected. And incomplete access to testing means that most infections will continue to be diagnosed only years after they were acquired.
In this situation a vaccine that would reduce peak viremia and viral load set point continues to offer significant value. Yet evolving clinical practices and clinical trials testing protocols increasingly complicate testing such a vaccine. So while the benefits of reduced viremia would be real, evolving clinical trial and treatment practices may have made it impractical to test for or detect such effects on viremia in the absence of other measures of clinical benefit.
When emerging best practices in treatment for the subject and for prevention are at odds with the requirements of clinical trial design, this presents an ethical dilemma. If it is not feasible to measure viral load set point as a primary end point in an efficacy trial, scarce resources should not be used on the development of products that reduce viral load only marginally.
But developers of such vaccines must put more effort into determining the mechanism of protection of their candidate vaccine and target immunogenicity to be observed in early phase clinical trials to justify the large expenditure of funds required for efficacy testing.
A vaccine that promotes complete clearance of virus after acquisition of infection is also a promising candidate for clinical development. Such a vaccine would provide protection against the disease of AIDS in the same way as the many licensed vaccines against other pathogens that do not prevent infection but rather help the body clear the infection more rapidly to reduce or prevent disease. But investigators interested in developing a vaccine for HIV that promotes viral clearance should work to develop a cost-effective assay for HIV-1 viral clearance.
Vaccines that reduce viral load set point substantially, especially to below the level of detection, may also still be testable but will require plans for long-term follow-up to ensure continued efficacy. Practical challenges in conducting large-scale clinical trials make developing an HIV vaccine about more than elegant science. Laboratory investigators must consider the complications inherent to the clinical testing of their vaccine approaches in product design and sometimes also be prepared to develop additional assays to facilitate clinical trials.
Scarce resources should not be consumed on the development of products without a feasible efficacy testing plan. Clinical development time should not be unnecessarily lengthened by inadequate preparation for foreseeable challenges in clinical efficacy trials. With increased thought about the implications of different product designs for clinical testing, HIV vaccine development could be accelerated.
Millions of people around the world are depending on the success of our efforts. Myron Cohen, Joseph Eron, and Charles Hicks, for making him aware more than 5 years ago of the importance of immediate treatment of individuals diagnosed with acute HIV-1 infection.
The author also wishes to thank Dr. Dennis O. The views expressed in this article are those of the author and do not necessarily represent the views or policies of the Department of Health and Human Services or the National Institutes of Health of the United States.
Along with increasing the sample size i. Thus the author allows that some of the vaccines that may be described as reduction in viral load set point vaccines may be licensable if the degree of reduction is profound enough to be observed in a small number of subjects and to overcome the postrandomization statistical bias concerns. Clearly the target reduction must be thoroughly discussed with regulators early in the development process and must factor into the powering of any efficacy trials.
This is probably only of academic concern as regulators will not require validation of clearance of infections not detected in the first place.
National Center for Biotechnology Information , U. Stuart Z. Author information Copyright and License information Disclaimer. Corresponding author. Address correspondence to:, Stuart Z. Copyright , Mary Ann Liebert, Inc. This article has been cited by other articles in PMC. Abstract Realization of individual and public health benefit from an HIV vaccine requires clinical testing to demonstrate efficacy.
Introduction T here are several ways in which a prophylactic HIV vaccine could provide individual as well as public health benefit Fig. Open in a separate window.
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