Safety and immunogenicity of a plant-produced recombinant hemagglutinin-based influenza vaccine (HAI-05) derived from A/Indonesia/05/2005 (H5N1) influenza virus: a phase 1 randomized, double-blind, placebo-controlled, dose-escalation study in healthy adults

Plant-derived pharmaceuticals for the developing world

Plant-produced vaccines and therapeutic agents offer enormous potential for providing relief to developing countries by reducing the incidence of infant mortality caused by infectious diseases. Vaccines derived from plants have been demonstrated to effectively elicit an immune response. Biopharmaceuticals produced in plants are inexpensive to produce, require fewer expensive purification steps, and can be stored at ambient temperatures for prolonged periods of time. As a result, plant-produced biopharmaceuticals have the potential to be more accessible to the rural poor. This review describes current progress with respect to plant-produced biopharmaceuticals, with a particular emphasis on those that target developing countries. Specific emphasis is given to recent research on the production of plant-produced vaccines toward human immunodeficiency virus, malaria, tuberculosis, hepatitis B virus, Ebola virus, human papillomavirus, rabies virus and common diarrheal diseases. Production platforms used to express vaccines in plants, including nuclear and chloroplast transformation, and the use of viral expression vectors, are described in this review. The review concludes by outlining the next steps for plant-produced vaccines to achieve their goal of providing safe, efficacious and inexpensive vaccines to the developing world.

Clinical vaccine development for H5N1 influenza

H5N1 is a highly pathogenic avian influenza virus that can cause severe disease and death in humans. H5N1 is spreading rapidly in bird populations and there is great concern that this virus will begin to transmit between people and cause a global crisis. Vaccines are the cornerstone strategy for combating avian influenza but there are complex challenges for pandemic preparedness including the unpredictability of the vaccine target and the manufacturing requirement for rapid deployment. The less-than-optimal response against the 2009 H1N1 pandemic unmasked the limitations associated with influenza vaccine production and in 2010, the President's Council of Advisors on Science and Technology re-emphasized the need for new recombinant-based vaccines and adjuvants that can shorten production cycles, maximize immunogenicity and satisfy global demand. In this article, the authors review the efforts spent in developing an effective vaccine for H5N1 influenza and summarize clinical studies that highlight the progress made to date.