The activation process of granulocytes is accompanied by the intense production of reactive oxygen species (ROS). Overproduction of ROS is cytotoxic, damages macromolecules and can lead to the occurrence of lipid peroxidation. Cellular defense against the toxicity of ROS is enhancement of detoxifying enzymes activation. Regulation of many detoxifying enzymes is mediated by the antioxidant response element (ARE) that is located in the promoter region of related genes. In eukaryotes, there are only few transcription factors known to be activated by ROS. One of them is NF-E2-related factor 2 (Nrf2). Normally, Nrf2 is present in the cytoplasm as an inactive Keap1-Nrf2 complex. However, after direct attack by ROS, Nrf2 is released from Keap1 repression and translocated into nucleus where it binds with ARE sequence to initiate gene expression. ROS may also influence nuclear factor-kappaB (NF-kappaB) intracellular signaling repressing the Nrf2-ARE pathway at transcriptional level. Since ROS are crucial in granulocyte-mediated tumor cell lysis the induction of NF-kappaB signaling pathway may be an important mechanism in suppressing the tumor growth.

India has over a century old tradition of development and production of vaccines. The Government rightly adopted self-sufficiency in vaccine production and self-reliance in vaccine technology as its policy objectives in 1986. However, in the absence of a full-fledged vaccine policy, there have been concerns related to demand and supply, manufacture vs. import, role of public and private sectors, choice of vaccines, new and combination vaccines, universal vs. selective vaccination, routine immunization vs. special drives, cost-benefit aspects, regulatory issues, logistics etc. The need for a comprehensive and evidence based vaccine policy that enables informed decisions on all these aspects from the public health point of view brought together doctors, scientists, policy analysts, lawyers and civil society representatives to formulate this policy paper for the consideration of the Government. This paper evolved out of the first ever ICMR-NISTADS national brainstorming workshop on vaccine policy held during 4-5 June, 2009 in New Delhi, and subsequent discussions over email for several weeks, before being adopted unanimously in the present form.