Immunity to diphtheria among children in northern Norway and North-WesternRussia

In 1990, diphtheria re-emerged in Russia and during the following four-year period the resulting epidemic reached all the Newly independent States (NI S) of the former Soviet Union. Several neighbouring countries of NIS, Norwa y included, have experienced sporadic imported cases. A sero-epidemiologica l study among children in Northern Norway and North-Western Russia was perf ormed in order to evaluate protection against diphtheria and how difference s in vaccination programmes affect immunity. A total of 664 sera, 400 from Norwegian and 264 from Russian children, were examined for antibodies again st diphtheria, using an in vitro toxin neutralisation method. The Russian c hildren studied had satisfactory protection in all age groups examined. The Norwegian children had poor protection against diphtheria from the age of 7 years until they received the booster dose at the age of ii. Therefore, a revision of the Norwegian vaccination programme, including a booster dose at school-entry age, seems warranted. (C) 2000 Elsevier Science Ltd. All ri ghts reserved.