Advancing new vaccines against pandemic influenza in low-resource countries.

With the support of the Biomedical Advanced Research and Development Authority (BARDA), PATH is working with governments and vaccine manufacturers to strengthen their influenza vaccine manufacturing capacity and improve their ability to respond to emerging pandemic influenza viruses. Vaccines directed against influenza A/H5N1 and A/H7N9 strains are a particular focus, given the potential for these viruses to acquire properties that may lead to a pandemic. This paper will review influenza vaccine development from a developing country perspective and PATH's support of this effort. Several vaccines are currently in preclinical and clinical development at our partners for seasonal and pandemic influenza in Vietnam (IVAC and VABIOTECH), Serbia (Torlak), China (BCHT), Brazil (Butantan), and India (SII). Products in development include split, whole-virus inactivated and live attenuated influenza vaccines (LAIVs). Additionally, while most manufacturers propagate the virus in eggs, PATH is supporting the development of cell-based processes that could substantially increase global manufacturing capacity and flexibility. We review recent data from clinical trials of pandemic influenza vaccines manufactured in developing countries. An important discussion is on the role of whole virion vaccines for H5N1, given the poor immunogenicity of split vaccines and the complexity involved in developing potent adjuvants.