Mass measles immunization campaign: experience in the Hong Kong Special Administrative Region of China
Chuang, S.K.; Lau, Y.L.; Lim, W.L.; Chow, C.B.; Tsang, T.; Tse, L.Y.
Bulletin of the World Health Organization 80(7): 585-591
2002
ISSN/ISBN: 0042-9686 PMID: 12163924 Document Number: 242674
After the 1988 measles outbreak, annual notification rates for measles in Hong Kong SAR between 1989 and 1999 were 0.4-4.9 per 100 000, with peaks in 1992, 1994 and 1997. The first half-year incidence rates per 100 000 were 2.3 in 1997, 0.5 in 1995 and 1.2 in 1996. Monthly notification rates increased from a baseline of <10 cases to 59 in May 1997. Serological surveillance showed only 85.5% of children aged 1-19 years had measles antibodies. An epidemic, mainly because of failure of the first dose to produce immunity, seemed imminent in mid-1997. A mass immunization campaign targeted children aged 1-19 from July to November 1997. The overall coverage was 77%. The rate of adverse events was low. After the campaign, measles notification fell to 0.9 per 100 000 in 1998. A two-dose strategy and supplementary campaigns will maintain measles susceptibility at levels low enough to make measles elimination our goal.