Updated: Jan 25
This article was submitted by *Dr. Wadinga D. Wadinga
Basic immunological response against invading microorganism which includes COVID-19 mounted by our bodies when attacked must be revisited here to make us understand so many things about COVID-19. Also, we note from the onset that given the pattern of COVID-19 infection the low-level protection against it in Africa, it is highly probable that herd immunity might have already been under way in much of Africa, a factor that might explain why infection, morbidity, and mortality rates due to the virus remain very low on the continent compared to Europe and North America.
Herd immunity happens when communities are infected, and antibodies are naturally developed in their body systems which protect against reinfection as recently found and published in UK Journal of Science. Though reliance on herd immunity is unethical, it has become apparent by the lack of adherence to the preventive protocols by Nigerians that this might have begun on a large scale already without knowing, particularly among youth in Africa. Despite this, the elderly and those with underlying medical complications remain vulnerable. Nevertheless, evidence from health facilities across Nigeria confirm large scale asymptomatic infections and recoveries, and it is certain that this category of people would no longer require COVID-19 vaccine injection for life. What needs to be done urgently is to examine the infections and recovery data to know how the elderly and those with preexisting medical conditions feature in the process. The results of such exercise will determine Africa’s actual inert vaccine requirements which should be locally developed biologically.
The morbidity and mortality due to COVID-19 have been varied across countries. But one confounding thing remains that the virus is yet to devastate Africa as earlier thought by global health experts, including the recent comments by Bill Gates who was surprised that his initial assessment that Africa would have been overran by COVID-19 by now, has not come to pass. To date, there are no scientific evidence to explain these country variations in COVID-19 infection, morbidity, and mortality rates, especially with regard to the situation in Africa. Unfortunately, there are no relevant research works yet going on to see if vaccines relevant to African environment could be found. This gap in knowledge represents a big challenge to Africa’s scientific community which should provide answers to the following questions:
a) Why have the COVID-19 infection, mobidity and mortality remained relatively very low in Africa?
b) Why do most of COVID-19 patients recover asymptomatic or with only mild symptoms in Africa?
c) Could lack of early antigen-antibody tests in Africa denied the continent the lead in vaccine development, which should be relevant to African environment given the storage conditions required for the Pfizer and Moderna vaccines develop in the West?
d) Given the low mortality rate due to COVID-19 on the continent and possibility of high-level herd immunity already achieved, should Africa still devote its scarce financial resource to the purchase of vaccines developed in the West?
Given the low coverage of child vaccination in many countries in Africa before now (with particular reference to Nigeria), what is the evidence that COVID-19 uptake will be higher, given that the socio-cultural factors militating against child vaccination uptake over the years have not changed? Will huge expenditure on the purchase of Pfizer and Moderna vaccines not be wastes, no thanks to the negative rumors peddled against the two vaccines by social media?
There are studies that suggest that people who had COVID-19 may have a second infection. This is to be expected as basic immunology confirms. But the subsequent infections will have a milder symptoms like the ones severally observed by health experts in Africa with regard to COVID-19, while a third infection has never been reported. This would suggest that some population in Africa would have had antibodies (immuned) to COVID-19 circulating in their system even before Pfizer and moderna vaccines came up. Research on the antibodies would have and still presents opportunities for Africa to develop vaccines unique to African environment.
The concern therefore is the lack investment in research into vaccines given that African Union even provides a platform for collaborative vaccine research in the event of lack of funds at individual country levels. If early lead were taken on the continent, it is possible COVD-19 vaccine could have been developed in Africa long before Pfizer and Moderna.
Immunity is divided into two major forms as follows:
a) Innate or natural immunity-means we are all born with it.
b) Adaptative or acquired-as its name applies–we all got it in some way or the other after we got exposed to some form of micro organisms, be it bacteria fungi or virus.
However at some points in time, the two forms commonly work together to achieve effective defense against microorganism preventing them from damaging our body systems. But for the purpose of this presentation, empahasis is put on acquired immunity which targets very specific microorganisms, a mechanism carried out by antibodies. Acquired immunity is further subdivided into two:
1) PASSIVE IMMUNITY –in this case, antibodies are formed outside the host body and injected when the individual is at risk and needs an urgent protection, it makes an antibody readily available at the time, because most times it may take days or weeks for the body to develop antibodies. The antibodies then attack the organism in our bodies before the organisms multiply to a dangerous level. Examples are Hepatitis B and C as well as Diphtheria, Pertussis and Tetanus (DPT).
II) ACTIVE IMMUNITY -Active immunity is formed when an individual comes into contact with a micro organism or its products. Immunity is acquired when bacteria, virus, fungi or any products of such foreign bodies enter the body system, it could be either in form of toxoids toxins which are all products or foreign materials. This initiates a process whereby the body through interactions of lymphpoid cells produces antibodies against that particular micro-organism such as COVID-19 for example. These antibodies are produced in large quantity to fight the virus and destroys it via a complex interaction with different blood cells like macrophages. Some of the antibodies produced can even last for life with some stored in form of memory cells just like the computer system memory. The body then makes available this antibodies whenever there is a future attack of any form.
The disadvantage of the active immunity is that it is usually delayed before the body produces the antibodies and also may need a repeated exposure before adequate antibodies get readily available. This may be a reason why some individuals may get a second repeat of COVID but never for the third time. This also explains why vaccines are given more than once at different times as in the cases of COVID and Hepatitis vaccines. The principles are the same for most immunizations.
Understand also that in most immunizations, the vaccines contain dead or attenuated organisms that cannot harm the body enough to trigger this proceess as described.
In conclusion, active immunity is the kind of immunity that is targeted at specific bacteria, virus or fungi. The human body system does most or all the process of making sure it produces some proteins called antibodies that either coat the surface of the invading organism to make it palatable to our body cells called macrophage to destroy it or produce some antibodies that can neutralise some invading organisms directly.
These processes, which are accomplished through a complex method by the body system are therefore to ensure that antibodies are produced to destroy invading organisms and to make some standby for any future attacks. The levels of these antibodies my go very low in the body system such that they are not detected by some of the tests usually done, which by no means indicate they are not present. That is why some vaccines are repeated just to boost them up. This also may explain why some individuals may have a second attack of COVID but in less severe forms. It is however certain that there can never be a third infection.
Passive immunity on the other hand is the injection of preformed antibody into humans to provide ready made soldiers to fight preemptive war against invading microorganisms. Both immune mechanisms can be used in individual at the same time.
African Governments and Health Scientists not being Proactive
COVID-19 has devastated the entire world with millions of hospitalizations and deaths. From the onset, concerted efforts were made in the developed countries to research into the understanding of the disease and very crucially to developed vaccines for stopping the pandemic. Meanwhile, African governments and their health departments waited for help from the developed countries, even for the minor supplies such as face masks, PPE, testing machines, etc. If Africa had taken the initiative into COVID-19 vaccine research, it would have been possible to develop a vaccine given the observed pattern of the disease on the continent.
All research efforts in the West were put into finding effective vacine against the virus and no thought of doing same or even to analyse the emerging data for the purpose of developing vaccine are contemplated in Africa. Yet, there are more than enough qualified health experts on the continent to make a big positive difference.
What is now required in Africa, in the light of large scale asymptomatic infections and recoveries, is to scale up rapid tests to determine the extent to which herd immunity has covered the population. Quite interestingly, COVID-19 statistics for Nigeria as at December 29, 2020 show 85,560 total infections, out of which there have been 71,937 recoveries and only 1,267 deaths, which is just about 1.5% of the total infections. Scientific analysis of the 1.5% death should be carefully analyzed in order to prioritise vaccine requirements in Nigeria, for example.
The cheering news here is that the 71,937 recoveries have most likely acquired life-time COVID-19 vaccine biologically.
Against this background, Africa should not be stampeded into devoting huge funds for the purchase of Pfizer and Moderna vaccines, but into research to actually know the pattern and the nature of COVID-19 infections, recoveries and deaths on the continent. For sure, something unique is happening to the virus in Africa given the associated low level of mortality due it. The reasons for this observation remain to be elucidated by well coordinated clinical research.
Until indigenous African clinician scientists are able to coordinate themselves, Africa shall continue to consume outcomes of Western research efforts and throw away evidence that could lead to efficient resource allocation.
*Dr Wadinga D. Wadinga is a Consultant General Surgeon with Adamawa State Specialist Hospital, Yola, Adamawa State, Nigeria.