“IMMUNIZATION AS A MOST COST-EFFFECTIVE PUBLIC HEALTH MEASURE” – by Professor Umaru Shehu, CFR; DFMC; FAS (B.496)
Annual Lecture, December 9, 2004
Let me, first of all, express my sincere thanks and appreciation for the
invitation by the Barewa Old Boys Association (BOBA) to deliver a
public lecture. It is a great honour afforded me to address an important
subject in front of such a distinguished gathering. When the President of
BOB~ my brother Professor BD M~ called me and informed me that I was
going to be invited to deliver a talk on the subject of Immunization, I was most elated. This is because I could not have chosen a better, more appropriate and more topical subject than this, if I had been asked to select the subject myself. You will see in due course why I feel this way.
HISTORY OF VACCINATION
Vaccination has always been intended to prevent susceptible persons from
contracting disease and to reduce its severity in the community. History tells us that disease is as old as man himself and human beings even in the early stages of the evolutionary path, knew that it threatened not only the well-being of sufferers and their fellows but also the integrity of the community as a whole.
Thus, they tried to maintain their health and to restore to health those who fell ill. It is this development that gave rise to the profession of Medical and Medical systems. I am not going into details even though history of medicine is a most stimulating and fascinating subject to study. Because the causes of diseases from which early man suffered from were not known, the methods of cure were based on supernatural and mystical formulae.
Early preventive measures were primarily designed to isolate the sufferers
from apparently healthy members of the community. Thus, isolation and
quarantine were introduced. With progress in the science of bacteriology
specific organisms were identified as cause of specific diseases. Thus, the
microorganisms which cause the following diseases were progressively
( covered (Smallpox, Tuberculosis, Cerebrospinal Meningitis, Diphtheria,
Tetanus, Pertussis, Measles, Cholera, Rabies ete).
The natural consequence of the further progress of the subject of
bacteriology was the discovery that when disease causing organisms enter the body they elicit a response. The pathogenic organism acts as an antigen and the body produces an antibody. Thus the subject of Immunology was born and this could be regarded as the turning point for disease prevention because it led to the possibility of immunization against disease. Sure enough, these events led to the production of vaccines against specific diseases, which were administered to healthy individuals who were then protected against the diseases. This gave a further boost to disease control by preventing susceptible persons from contracting communicable disease then prevalent in the community.
Despite additional public health measures, which were introduced in the
16th and 17th centuries and extending into the 20th century, comprising of
improvements in hygiene and sanitation, better housing and nutrition,
outbreaks of infectious diseases continued to occur in devastating proportions. I will now try and illustrate this by talking about smallpox and poliomyelitis.
Going back in history, we found out that vaccination had been practiced for thousands of years. The term scarification was used then to describe the practice, which was specifically to prevent susceptible persons from contracting the disfiguring and deadly disease of smallpox. More recently, Lady Mary Wortley Montague, the wife of the British Consul in
Constantinople, (Istanbul) was reported to have introduced smallpox
vaccination into England. In 1717, she had described the inoculation of
smallpox susceptible persons routinely by Turkish women. This was also said to be common in India. She claimed that those that were so inoculated with the material from smallpox sufferers were protected against
the deadly natural form of smallpox. The Royal Society of London subsequently published Lady Montague’s observation in its philosophical transactions.
The adoption of this practice drastically reduced the incidence of smallpox>
in England. As at that time 10% of all deaths were as a result of smallpox. To show that the disease knew no bounds, Queen Mary of England and King Louis of France both suffered from the disease. During a very severe epidemic as many as 40% of sufferers died.
The effect of the inoculation was to reduce the incidence of smallpox as
well as its severity. Thomas N ett1eton reported to the Royal Society of London thus: To give plain proof from experience and matters off act that the smallpox procured by inoculation is far less dangerous than the same distemper has been for many years in the natural way.
EDWARD JENNER 1789 - 1823
Edward Jenner observed that milkmaids who suffered from cowpox did not subsequently suffer from smallpox. He investigated the protective nature of cowpox and on May, 1796, carried out arm-to arm inoculation of cowpox pustule to susceptible human beings. Six weeks later he inoculated the same people with the discharge from a child suffering from smallpox and the vaccination did not take proving that the cowpox had protected them from smallpox. In 1798 Jenner published his report under the title” An inquiry into the causes and effects of the variola vaceinae”. From then on the vaccination against smallpox was adopted all over Europe with Sweden being the first country to make it compulsory.
After the Second World War, a meeting of leaders from fifty-five countries and their top scientists took place in Geneva under the auspices of the World Health Organization to review the State of Health of the World. It was at this meeting that Health was defined as “a state of complete physical, mental and social wellbeing and not merely the absence of disease or infirmity”. Following the review, there was a realization that children bore the brunt of ill health in every part of the world. The childhood infectious diseases directly caused most of the morbidity and mortality. This motivated the WHO to launch immunization campaigns to vaccinate children against Diphtheria, Tetanus Whooping cough, Tuberculosis and Measles.
In 1966, the World Health Organization reported that 10-15 million people in 33 countries suffered from smallpox and up to 2 million of them died each year. The WHO launched a ten-year campaign for the eradication of smallpox and control of measles worldwide. By 1977 total eradication of smallpox from the entire world had been achieved. Efforts to eradicate other infectious diseases however, did not yield that desired result and the major childhood killer diseases continued to occur in epidemic proportions.
The WHO had articulated programmes to eradicate other infectious disease worldwide. The initial failure of these programmes was due to the inability to meet the pre-requisites for the eradication of diseases, which include:
Technical, Scientific, Political, Economic, Social, Religious and Human
Resources requirements. More than two hundred years ago, that was in 1801, Edward Jenner made the optimistic statement: “it now becomes too manifest to admit of controversy; that the annihilation of the smallpox, the most dreadful scourge of the human species, must be the final result of this practice” (vaccination). One hundred and seventy-six years later, his prediction was realized. In a review Dr. Donald A. Henderson, who was a part of the smallpox eradication team, explained why the World Health Organization singled out smallpox for eradication based on certain special characteristics:
Ø Availability of a heat-stable vaccine
Ø Single dose was adequate for immunization
Ø Man was the only known reservoir of infection
No other disease had come to matching these characteristics. Despite
the clearly and rationally demonstrated effect of vaccination in preventing smallpox, many countries had to be persuaded with difficulty to participate in the global smallpox eradication programme. Luckily, Nigeria came on board early and succeeded in executing the programme successfully. We certainly did eradicate smallpox before many countries.
Paralytic Poliomyelitis or “Cutan Shan Inna” (Hausa) has been known for more than 3000 years. Documented evidence in Egypt then showed an Egyptian stele portraying a priest with a withered leg leaning on a staff suggesting that he had suffered from poliomyelitis! Paralytic poliomyelitis has, therefore, been known to occur sometimes in epidemic proportions from time immemorial.
In 1840, Dr. Jacob Von Heine first described the deformities of
poliomyelitis and for the first time developed the theory that the disease may be contagious. Available literature and orally transmitted information all point to the fact that a British physician Medin was the first to describe the clinical picture of poliomyelitis in 1887. By 1990, poliomyelitis epidemics were being reported worldwide-and became a notifiable disease in 1912. For example, in the 19th century, frequent and devastating epidemics were reported with crippling consequences of thousands of victims each year. Then scientists were not sure of its cause and virtually nothing could be done to curb the epidemic. However, the turning point came when Franklin D. Roosevelt contracted the disease in 1921 and was paralyzed. Despite that, he fought the elections and became the President of the United States of America.
The disease was then called Infantile Paralysis because it paralyzed only
children. The election of Roosevelt led to the establishment of the National Foundation for Infantile Paralysis. This resulted in the intensification of research into the causes and prevention of poliomyelitis. The first vaccine was tested in 1935 and despite some deaths and paralysis from the vaccination, research was not halted because the objective was sound, noble and, in the opinion of the scientific world, achievable.
In 1953, Dr. Jonas Salk developed and tested the first Injectable vaccine
against poliomyelitis, which consisted of inactivated Polio virus. The vaccine was not widely used due to some attendant risks after its administration.
Following further work, the Salk vaccine was declared safe and effective in 1955 after the initial risks had been eliminated. This vaccine is used only in a few countries like the United States today. Dr. Albert Sabin had been working on a different type of vaccine and he eventually succeeded in developing an oral polio vaccine based on the attenuated live polio virus. This is now the vaccine of choice in most parts of the world because of its effectiveness, efficacy, safety and ease of administration. Some of the earlier trials were conducted in Cuba, Hungary and Czechoslovakia. The Countrywide immunization with the trivalent vaccine demonstrated that the wild poliovirus could be eliminated in large geographic areas, thus providing the basis for eradication.
Even though these achievements suggested that effective use of the vaccine could lead to global eradication of the disease, several barriers persisted, including acceptance in the most at-risk populations and lack of data for evaluating the effectiveness and impact in developing countries.
Prior to 1988, up to 120 countries were reporting poliomyelitis cases which left no less than 350,000 children paralyzed annually. By the end of1988 the global annual reported cases of poliomyelitis had dropped to 35,251 which was a clear indication of the effectiveness of polio immunization under the Expanded Programme On Immunization (EP1). The figure further dropped to 3,995, an eight-nine percent drop, in 1996 as result of the introduction of Polio Eradication Initiative (PE!). The magnitude of the poliomyelitis burden was better appreciated in the African Region by WHO when surveillance improved. Africa accounted for fifty percent of the global burden of poliomyelitis cases. This was the consequence of the failure or inability of vaccination with OPV to reach every susceptible child because it depended on fixed health institutions
like hospitals, clinics and dispensaries. The logical development was the introduction of House-to-House campaign in order to reach all the target child population aged 0-59 months in the community.
At the end of 1998, 50 countries in the world were known or suspected to be polio-endemic and thirty-six of them are in the African Region. By the year 2003, only seven countries were known to be polio-endemic in the world i.e. Afghanistan, Bangladesh, Egypt, India, Niger, Nigeria and Pakistan.
Polio Eradication is Based on Four Strategies:
1. Routine immunization of infants soon after they are born with four doses of oral polio vaccine.
2. Mass campaign known as National Immunization Days, during which, all children under five years of age are vaccinated, regardless of whether or not they have been vaccinated before.
3. Effective surveillance to find and investigate every newly paralyzed child to determine if the case is polio (known as Acute Flaccid paralysis or AFP surveillance).
4. Mopping-up campaigns to reach every child with the polio vaccine in the final stages.
HISTORY OF VACCINATION IN NIGERIA
It will certainly not surprise anyone if I tell you that documentation
regarding this subject is very scanty indeed. However, there were reported
cases of devastating epidemics of smallpox published dating back to the latter part of the 19th century. At that time control or treatment of the disease in many parts of Nigeria was based on the worship of the smallpox god according to the British. It is on record that the British Colonial Administration introduced an Ordinance in 1907 forbidding the worshipping of the smallpox god because some of the practices, in fact, encouraged the spread of the disease. The British also introduced fumigation of houses. Travelers from Britain were, of course,
vaccinated and, therefore, were immune to smallpox. Vaccination was then
provided at fixed health institutions like hospitals and dispensaries.
service became available outside health institutions during epidemics; when roadblocks were erected to enable the vaccination of all those who did not show the scar of vaccination.
Apart from being vaccinated by vaccinators, I became a direct participant as soon as J qualified as a doctor and returned home nearly fifty year ago, this time by supervising the vaccinators particularly with the introduction of routine immunization of children under the Expanded Programme on Immunization (EPI). However, my role changed on being posted to the Headquarters of the Northern Nigeria Ministry of Health in Kaduna and eventually took over the post of Chief Medical Officer, Preventive Services Division. The primary function of the Division being to promote healthy lifestyles and to prevent diseases. The first and most demanding challenge we faced was the implementation of the Small-pox eradication and Measles control programme in the mid 1960’sandfirsthalfofthe 1970’s. The WHO and partners like USAID, CDC etc. collaborated with us in implementing the programme. I was designated the counterpart officer and participated in the planning stages of the worldwide initiative and during implementation we had to be conscious of such issues as the safety of the vaccine, the adverse events following vaccination and cultural sensitivities.
I got so deeply involved to the extent that I undertook personal research on the effectiveness, efficiency and safety of the vaccine. In fact, the subject of my Major Infectious Diseases in an Overseas Country”. I chose Smallpox and yellow fever and the country was Nigeria. I still have the original document. The campaign against smallpox was so successful that there were no cases of the disease in Nigeria by 197 Sand global eradication was achieved in 1977.
Since there is no treatment for Poliomyelitis, prevention by vaccination is the only alternative. Two questions have often been asked in relation to
immunization with the Oral Polio Vaccine (OPV).
1. How safe is the OPV?
2. How effective is the OPV?
Immunization against Poliomyelitis with the OPV became available to us
in Nigeria early in 1960. To show that we were very much conscious of our responsibilities to our people, we were determined to find answers to at least these two questions before adopting the practice generally. This was clearly illustrated by a letter written by the then Permanent Secretary in the Ministry of Health of Northern Nigeria to the then Minister of Health, Northern Region. I have a copy here with me and it is dated 07/03/1960. By early 1964, we had completed our investigations and the questions concerning the effectiveness and safety of OPV had been satisfactorily answered resulting in the administration of OPV in routine immunization throughout Northern Nigeria.
I have a letter here dated 20th May, 1964 in which the Ministry of Health announced the availability of OPV for distribution throughout the North.
Rumours and speculations were not allowed to get out of hand and the
responsible manner in which the issues were handled and resolved enabled us to continue to vaccinate with OPV for forty years without any authentic, reliable and significant evidence of any serious adverse effects. Speculation must never be allowed to take over from reality.
When the Polio Eradication Initiative (PEI) was launched worldwide in
1988, I was based in Zimbabwe as the Director of the Sub-Regional Health Development Office in-charge of WHO programmes in 16 countries. One of my responsibilities was to ensure the success of the PEI in those countries.
However, I had to leave my post following my retirement from WHO two years later. I am proud to say that all those countries eventually succeeded in eradicating the wild polio virus. Back home in Nigeria, it was clear that routine immunization was doing reasonably well. But the introductions of the Polio were inadequate human and material resources. There was also the feeling that we did not own the programme. It is in order to develop a programme of vaccination largely owned and managed by Nigerians that the EPI was renamed NPI and legalized through
an Edict. The Board of the NPI was inaugurated in December 1995 and in January 1996 I was appointed the Chairman and National Coordinator of the Programme. By the time I completed my four years assignment, we had recorded some successes. Routine immunization rates had reached up to 80% in some states, the co1d- chain had been upgraded and staff training intensified.
But because the coverage of the target population with OPV was still low
for eradication of Polio, Nigeria with the cooperation of partners, like WHO, UNICEF and Rotary International introduced the House-to-House strategy. It was at this point that speculations began to emerge as to the safety of OPV and whether it had any adverse effects. Some sections of the society decided to halt the administration of OPV. The challenge which now faced the nation was to prove that OPV was safe. Several individuals and groups got involved in the process of verification of the safety of OPV. Such national institutions as ABU Teaching Hospital, Abuja, and NIPR undertook tests. The interpretations of the results generated some controversy and a conclusion was not reached. Consequently, the Federal Government sent a team consisting of Scientists with me as Chairman to South Africa where two reputable laboratories were engaged to test the samples of OPV from Nigeria which we delivered to them. The results from these two laboratories and those from Nigerian Institutions were the subject for discussion at a technical committee meeting chaired by me. Although the consensus was that OPV was safe there were skeptics who called for an all-inclusive team to undertake further tests.
Thus a team consisting of nominees of the Federal Government and Jamaatu Nasri1 Islam (JNI) took OPV samples to South Africa, Indonesia and India for further tests. I participated in this exercise too.
With these results in our possession and after several meetings with
stakeho1ders, we were able to resolve the issue of the safety of OPV and
vaccination with OPV resumed nationwide subsequently. There is no doubt, however, that we had suffered a serious set-back in our effort to
eradicate polio from Nigeria as part of the global polio eradication initiative. Since the controversy is now behind us it is not my intention to try and apportion any blame to any individual or group for what appended. The other reason is that since I am not a Traditional Ruler, a Religious leader or a Politician, I could not even pretend to be capable of guessing what went on in the minds of these categories of stakeholders. What part they played and why in the genesis and propagation of unfounded and unsubstantiated rumours about the safety of OPV which resulted in the cessation of Immunization of our children with the OPV are only known to them, the one thing I do know are the serious adverse consequences of their actions.
However, I cannot help but to comment on the role played by some of our scientists and their behaviour during the period of the controversy. It is certainly inexcusable for any honest and competent scientist using the state-of- the-art equipment to test any sample and then come out with a report which states that the sample contained “CONTAMINANTS”. This is neither scientific nor honest but designed only to mislead and to continue to fuel the crisis. Even more disappointing and puzzling was when laboratory scientists stray out of their areas of competence to pronounce on the clinical effects of any substance like hormones on human beings, these being in the domains of Obstetricians and Gynecologists, Pediatricians and Endocrinologists. This obvious shortcoming was not taken into account seriously enough thus perpe1rating the rumour that OPV was not safe to be administered to children because it contained “contaminants”.
I can only characterize what happened by quoting a statement which goes as follows: “The secret of a successful presentation of dubious findings is sincerity. Once you can fake that you have got it made” . I had tried to get to the root of the questionable behaviour of some of our scientists and had concluded that they were victims of a phenomenon called “conflict of interest”. This is a global problem to the extent that no reputable scientific journal will publish today any article, report or research result without a declaration by the writer that there is no conflict
of interest because it is the .worst enemy of honest scientific endeavour. It is my prayer to Allah (SWT) that this nation will never again experience a similar situation either with the PE programme or any other future vaccination programmes to control or eradicate other diseases. Let me at this stage remind us that the title of my presentation is “Immunization as a cost-effective measure in public health”. I will use two examples to illustrate the cost-effectiveness of immunization.
BCG is one of the first vaccines to be administered to the body at birth and that single dose will protect the child for life from tuberculosis. That one dose of BCG costs just 0.093 US dollars, which is equivalent to N13.02. Compare this with the cost of treating a case of tuberculosis. Once con1racted by an unvaccinated person it will require treatment with costly drugs for a minimum of nine months which will cost hundreds of thousands of Naira. Even more costly is the permanent, damage done to the lungs and its long term consequences.
The first dose of OPV is also administered to the baby at birth with three more doses following at six weekly intervals. A fully immunized child is protected from Poliomyelitis for life. The effectiveness of OPV in preventing Poliomyelitis is unequivocal when we look at the decline in the number of cases worldwide and the total elimination of the wild poliovirus in most countries of the world since the introduction of the PEI. The cost of fully immunizing a child with the OPV is only 0.13 US dollars, which is equivalent to N18.20. Compare this with the costs incurred in the event of a child being crippled by Poliomyelitis. These cannot be quantified only in terms of Naira and Kobo because there are educational and social consequences among others, which we are all aware of i.e. inability to go to school and be educated, failure to secure a job and get married and have children. For most of those afflicted the only alternative seems to be street begging. I do not think one has to be a health economist, therefore, to conclude that indeed there is no public health measure which is as cost-effective as immunization.
As you must have noticed I have avoided making reference to specific issues particularly with respect to the recent controversy on the safety of the OPV. Having been involved with the use of OPV to immunize children in Nigeria for nearly 50 years and having encountered no adverse effects of any consequence you will appreciate my disquiet at some of the claims, which were widely published. My approach, while the controversy lasted was to try and disseminate the correct information based on my personal experience.
Information, which no rational person would dispute was passed on to
traditional, religious, community and political leaders at several meetings that I held with them.
I have always been an optimist and I am now convinced more than ever before that together we can succeed in stopping the transmission of the wild Poliomyelitis virus in Nigeria by the end of the year 2005. At this point, I would like to pay tribute to Traditional, Religious and Community Leaders who contributed in no small measure to the final establishment of the truth that OPV is safe, thus engendering trust amongst all stakeholders resulting in the resumption of the NIDs and SNIDs nationwide.
I cannot end this lecture without throwing a challenge to the BOBA. I
believe we reached the stage of focusing on national issue which affect the welfare of our people a long time ago. I recall the setting-up of the Turaki Committee and its Health Sub-Committee on which I was to serve. My records show that the letter I addressed to the Secretary dated 13th August, 1998 did not elicit any response. However, I am yet to be aware of a situation where we have made an impact. I may be wrong. Be that as it may, 1 think it is now time for BOBA to play a pro active role in such areas as the promotion of health, education etc. Why should BOBA not establish a Health Committee, for example, to advise the Association on the way forward particularly when programmes for the eradication of diseases are being planned? We have enough expertise to ‘advise on which disease should be the next subject of eradication using immunization as the main strategy.
Well, all good things come to an end as the saying goes. It is now time to end this lecture by thanking everyone for their attention and to wish them safe return to their respective destinations.
May Allah (SWT) bless you and guide you throughout your lives. Amin.