The Korean Influenza National Immunization Program: History and Present Status

Yun, Jae-Won; Noh, Ji Yun; Song, Joon Young; Chun, Chaemin; Kim, Yunju; Cheong, Hee Jin

When the NIP for influenza was established in 1997, the recommended period for vaccination was from September to October. However, because of the delayed occurrence of influenza outbreaks, the vaccination period was later changed to September-November in 2002 and September-December in 2004. Considering the fact that the effects of a vaccination last up to 6 months on average, the vaccination period was adjusted to October-December in 2005 and has remained so until now (except for the 2009-2010 and 2010-2011 seasons when the vaccination period started early (September-December) to include the H1N1 influenza vaccine) [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] . In 2017, free vaccine recipients were expanded to cover young children from 6 months to <5 years old. As such, for those infants receiving their first twodose vaccination, their first dose was given in early September and the second dose was completed before the start of the season to develop sufficient immunity. Infants who reach 6 months of age after January 2018 will be allowed to receive free vaccinations until the end of April 2018 [17] .