National Immunisation Day

National Immunisation Day part of a special immunisation programme on polio eradication. Polio is primarily a disease of the infant caused by an enterovirus with disease manifestations that include destruction of motor neurons in the spinal cord causing flaccid paralysis. Because of enteric entry of the virus, it was thought that an oral vaccine may be effective in stimulating immunity against the disease. Indeed, oral vaccines consisting of attenuated virus have proved to be highly effective in conferring protective immunity. The trivalent polio vaccine consisting of three poliovirus types currently in use is a very convenient preparation that can be kept at 4'C for a long time and is thus suitable for field use in simple iceboxes.

Like many countries where polio has been eradicated using the vaccine, Bangladesh also has adopted a polio eradication policy in 1995 using oral polio vaccine (OPV) given to every eligible child. As a part of the programme, a National Immunisation Day (NID) is observed every year when millions of eligible infants under the age of one year are given two drops of oral polio vaccine. The first and the second dose of the three doses of OPV are given about a month apart while the third dose is usually given through the routine immunisation programme of the government, now called the Extended Programme of Immunisation (EPI) where six vaccines are used such as diphtheria- pertussis-tetanus (DPT), OPV, measles and BCG.

A contributing factor to the success that has been achieved on OPV vaccination is the observation of National Immunisation Day. On this day special countrywide arrangements are made to administer the vaccine through an elaborate network of community health care centres and with the participation of a large number of volunteers. A massive awareness campaign is set in motion a few weeks prior to the NID to make the day widely known, urging mothers to report to the nearest vaccination centre on the day. It is certainly a highly credible accomplishment that on each NID millions of children are immunised with the vaccine.

The first NID was observed on 16 March 1995 for the first dose of OPV and 16 April for the second dose. The subsequent NIDs were: Second NID 16 April and 16 May 1996, Third NID 8 December 1996 and 8 January 1997, Fourth NID 7 December 1997 and 18 January 1998, Fifth NID 14 December 1998 and 2 February 1999. Coverage rate is nearly 100% of the target group of children. For example, during the Fifth NID, 20 million children were given the vaccine which represented over 100% of the target. During every NID, children are also given a dose of vitamin A (100,000 units) to ameliorate vitamin A deficiency and reduce the incidence of night blindness which is caused by vitamin A deficiency.

The target of polio eradication from Bangladesh was initially set at the year 2000, but the date is likely to be shifted to the year 2005 by which time it is hoped that Bangladesh will become a polio free country. [Zia Uddin Ahmed]