问答题 The spread of the virus can be controlled through basic sanitary practices, including washing hands, wearing face masks, and disinfecting potentially contaminate surfaces. However, the most effective method of prevention for high-risk persons, including young children, women who are pregnant, and individuals with compromised immune systems, is vaccination. When the H1N1 VIRUS emerged, there were no vaccines available that could provide immunity against infection. However, the severity of the outbreak prompted the rapid development of a novel vaccine, which was tested in clinical trials beginning in early August 2009. Because the first vaccine tested require two doses, there was immediate concern that not enough vaccine could be manufacture before a potential second wave of illness arrived in the fall in the Northern Hemisphere. By September, pilot tests of novel single-dose vaccines indicated that sufficient protection could be provided by one injection. Sinovac, a Chinese company, received approval from the government in early September to begin mass production of the vaccine, with the goal of generating enough of the agent to vaccinate 5 percent of the Chinese population by 2010.无