March 28, 2011
A boy is vaccinated during a day of the vaccination campaign against Influenza A H1N1 Virus (swine flu) in Ciudad Juarez, Mexico. A new outbreak of H1N1 in northern Mexico, which left four dead in the past week, originated in the southern United States, the Chihuahua state governor said. Mexican authorities have started a vaccination campaign in northern Chihuahua and ruled out the risk of an emergency on a similar scale to 2009, when Mexico raised the first H1N1 alert. Swine flu -- so named because it was first identified in pigs -- has killed some 18,500 people since emerging in April 2009, according to the World Health Organization (WHO).