DNA Vaccines: Scientific and Ethical Barriers to the Vaccines of the Future

| November 15, 2011 | 0 Comments

Image courtesy of the Los Angeles County Supervisor’s Office.

As flu season rolls around once more, DNA vaccines have regained attention in scientific debates. Hailed as a promising alternative to traditional vaccines, which utilize attenuated or dead viruses, DNA vaccine technology offers promise toward many new developments, including a potential universal flu vaccine that could be released within the next five years. However, the development of a universal flu vaccine has stalled due to a number of concerns including the efficacy, safety, and ethics of conducting clinical trials in developing countries.

DNA vaccines work by causing the body to translate  the injected DNA sequences into pathogenic proteins. The body then creates antibodies specific to the proteins, which confers immunity without causing  infection. This is important for immune-compromised patients, including those infected by HIV. These vaccines are also easier to distribute than traditional vaccines because they are more stable, avoid the risk of accidental infection by the pathogen, and require no refrigeration. These features are appealing to practitioners in the developing world, burdened with disease-susceptible populations and lack of proper infrastructure for maintaining traditional vaccines.

However, there is limited knowledge of the effects of these DNA vaccines on humans, since most tests have only been conducted on lab animals. Potential side effects could include chronic inflammation, because the vaccine continuously stimulates the immune system to produce antibodies. Other concerns include the possible integration of plasmid DNA into the body’s host genome, resulting in mutationsproblems with DNA replication, triggering of autoimmune responses, and activation of cancer-causing genes.

The array of side effects identified also raises ethical concerns for the establishment of clinical trials for DNA vaccines. In general, pharmaceutical companies can border on exploitative in their use of developing countries’ populations in research. These developing countries often lack solid legal and ethical frameworks to handle clinical trials. In the U.S., existing law protects rights of the participants through requirements that include review of research by Institutional Review Boards, which minimizes risk to participants and balances harm-benefit ratios.  However, developing countries often do not have these laws or might enforce them less strictly.

In addition, vulnerable populations in the global South are frequently utilized for clinical trials that test drugs for afflictions often more relevant to the global North than to themselves. This results in a type of ethical double standard; the clinical trial itself becomes a means for the volunteers to receive medical care, but the actual drug tested by the clinical trial results in few returns for the participants in the end. This also leads to ethical concerns in that trial participants may be coerced into trials by the promise of such care. Therefore, it is ethically just to ensure that DNA vaccines tested by clinical trails in the developing world actually benefit the populations participating in such studies.

A focus should be placed not just on the development of treatments such as DNA vaccines for numerous diseases, but also on ensuring the safety of the human subjects who receive them. By improving both the scientific understanding of the DNA vaccine and the legal guidelines in place to test and distribute it, we can advance this new technology with confidence in its safety and relevance to target populations.

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Category: Online, Technology

About the Author ()

Audrey Zhang '15 is the webmaster for HCGHR and a Technology and Global Health online columnist. She is a resident of Adams House concentrating in History of Science with a focus on Medicine and Society, and a secondary field in Global Health and Health Policy. In her spare time, she enjoys competitive reading and Tazo tea.

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