The immunogenicity of the combination vaccine is at least as good as the monovalent vaccines[54, 55] and is particularly useful as many travelers also require hepatitis A vaccination.[18] Ambrix (inactivated HAV and recombinant HBsAg) is licensed in Europe as a two-dose schedule in children aged 1 to 15 years.[56] HCV

is a member of the Hepacivirus genus within the Flaviviridae family.[57-59] It is estimated that 3% of the world’s population is chronically infected.[60] The prevalence is estimated to be 3.2% in China, 4.8% in Pakistan, and up to 15% in parts of Asia and Africa. CHIR 99021 The highest prevalence of HCV is in Egypt (15%–22% of the population)[61-64] (Figure 2). HCV transmission generally results from parenteral exposure to contaminated blood via injecting drug use (IDU), blood transfusions, unsafe injections, medical procedures, body piercing,

or tattooing. It may also occur via perinatal transmission. Sexual transmission of HCV has been described among HIV-positive men who have sex with men, and is associated with high-risk sexual behaviors.[58, 65, 66] In approximately 20% of people no cause of infection can be established. The risk of occupational transmission of HCV needlestick injuries is around 0.3%.[67] Perinatal transmission PCI-32765 price from HCV-infected mothers occurs in 2.7% to 8.4% of births.[67] The widespread practice of paid donor blood and poor screening has led to high HCV transmission rates in the developing world. Screening for HCV in blood and blood products is not universal in many developing countries[40]: the WHO estimates that 43% of donated blood in the developing world is inadequately screened.[67]

The frequency of reuse of injection equipment without sterilization also varies, with highest rates in Southeast Asia and the Middle East (1.2%–75%).[68] Unsafe injecting practices in developing countries such as Egypt, India, and G protein-coupled receptor kinase Pakistan led to the formation of the Safe Injection Global Network (SIGN).[67, 69] The SIGN was established in 1999 and aims to achieve safe and appropriate use of injections worldwide. The WHO through collaborations with national regulatory authorities has focused on formulating national policies for: the safe and appropriate use of injections, the quality and safety of injection devices (in particular, single-use injection devices and auto-disable syringes), facilitating access to injection equipment, and achieving cost-effective use of injections. Intervention strategies targeting these core components simultaneously have improved vaccine injection safety.[67, 69] Acute HCV infection is usually asymptomatic and unrecognized, with <1% of HCV-positive individuals reporting an acute illness associated with jaundice.[70] Following infection, HCV RNA begins to replicate in the human liver and is detectable in the serum within 1 to 3 weeks.