RIYADH: Students in Riyadh’s 4,700 schools will be vaccinated against seasonal flu as part of a campaign by the Department of School Health Affairs and the Department of Human Resources. The vaccination program was launched on Sunday by Hamad bin Nasser Al-Wahaibi, director-general of the Riyadh Education Department. Director of School Health Affairs, Dr. Hamad bin Abdullah Al-Hajjri, said that the campaign aimed to prevent seasonal flu, which spread easily at this time of year. The flu virus can be transmitted in the air or by touching contaminated surfaces. The infection period ranges from one day before the onset of symptoms to up to seven days afterwards, but can continue for a longer in children and adults with immune deficiency, he said.