IN the last week of April, World Immunisation Day was commemorated worldwide. This year, both the Ministry of Public Health and the media gave an unusual focus on the week and there were public outreaches as well.

The momentum for immunisation has been continuing and this could be attributed to the fact that most of the population have begun to realise the value of immunisation and because more Guyanese are now visiting or even settling in the neighbouring countries. In these countries, they do not have as developed an immunisation programe as Guyana, with the result that they sometimes suffer epidemics of diseases such as yellow fever or measles, which Guyana’s vaccination programmes have almost eradicated.
Immunisation is the process whereby a person is made immune or resistant to an infectious disease, typically by the administration of a vaccine. The vaccine stimulates the body’s own immune system to protect the person against subsequent infection or disease. Vaccination and immunisation are not the same; immunisation occurs after the vaccination has been administered.

Before the advent of vaccinations, the only way people became immune to an infectious disease was by being infected with it. In the early 18th century, for example, smallpox was prevented this way by having one infected with a milder form of the disease than the natural disease. Dr Jenner’s discovery of the use of cowpox for vaccination against smallpox opened the doors to modern immunisation.

Throughout history, epidemics of infectious diseases have periodically attacked human populations. Two of the most well known were the bubonic plague or Black Death, which killed about two-thirds of the population of Medieval Europe and up to now memories of the Black Death still linger in the European consciousness.

The other was the smallpox epidemic which killed off half of the indigenous Amerindian population of the New World after the Spanish conquest. Smallpox was a disease unknown in the Americas and as such, the Amerindian peoples had developed no immunity. When the disease was introduced by the Spaniards, it quickly killed off the native populations.
The discovery and use of immunisation is one of the greatest achievements of western medicine. Among the infectious diseases which have been brought under control or eradicated in some countries are typhoid, whooping cough, mumps, measles, chicken pox, diphtheria, tetanus, hepatitis B, polio and of course, smallpox. Recently, it has been announced that cervical cancer has been added to the list.

Guyana, having been a British colony, health procedures and programmes which were used in the mother country were in time applied here. Thus, very early universal smallpox vaccination became part of the health services and babies in the hospitals and children at school were vaccinated. Seventy or 80 years ago, there was some fairly strong resistance against vaccination and parents would try to avoid having their children vaccinated, since the child would oftentimes have a fever after vaccination or the point at which the incision on the arm was made would sometimes become inflamed. Today, such resistance has passed away since the public are aware of the value of vaccination.

In the last three or four decades, the vaccination system became well organised. Babies in the hospitals are routinely vaccinated as well as all children of five years and under. Later, the vaccination programme was extended to pregnant women and older persons. It should be mentioned that vaccination for a number of diseases could be given at the same time. The most popular are those which are required when travelling abroad such as yellow fever, polio, hepatitis B, tetanus and typhoid in addition to small- pox.

Vaccination coverage is an almost obligatory requirement for such groups as the military and armed forces, teachers and health care workers. Devoted health care workers are committed to bringing vaccination to such groups as miners and fisherfolk, as well as children and adolescents. Guyana has now achieved over a 90% vaccination coverage and the minister with a touch of hyperbole described the activities of health workers as: “They have waded through swamps, had their boats overturned, used ATVs up slippery mountains, faced feral animals, slept in tents outside of their own beds, borrowed fuel, hitched rides, gone hungry”. . . Vaccination workers have had a particular focus on the borders and points of entry since the neighbouring countries, from time to time, have had epidemics of infectious diseases. The theme of this year’s vaccination week was “Strengthen your defence, get vax!” and this slogan is likely to be used for some time to come.