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*Corresponding author: E-mail: albertopk2000@yahoo.co.uk; 
 
 
 

Asian Journal of Immunology 
 
3(1): 278-282, 2020; Article no.AJI.58254 
 

 
 

 

 

Discussion on the Concept of Immunity and How 
Human Body System Could Build Immunity against 

COVID 19 and It Relevance to Public Health 
Education 

 
Albert Opoku1*, Joana Owusu Danso1, Olivia Nyarko Mensah1, 

Nicholas Amoah Owusu2, Prince Twene2, Jefferson Asare Dankwa3  
and Andrews Owusu4 

 

1
Nursing and Midwifery Training College, Kumasi, Ghana. 

2
Food and Drug Authority, Ghana. 

3
Ghana Health Service, Ghana. 

4
Konongo Odumasi Hospital, Ghana Health Service, Ghana. 

 
Authors’ contributions 

 
This work was carried out in collaboration among all authors. Author AO designed the study and did 
the literature review with authors JOD and ONM. Authors NAO and PT wrote the protocol and wrote 

the first draft of the Manuscript. Authors JAD and AO edited the Manuscript. All authors read and 
approved the final manuscript.  

 
Article Information 

 
Editor(s): 

(1) Dr. Wagner Loyola, Brazilian Agricultural Research Corporation, Brazil. 
Reviewers: 

(1) Asmaa Abdallah Darwish, Desert Research Center, Egypt. 
(2) Hasta Handayani Idrus, Universitas Muslim Indonesia, Indonesia. 

Complete Peer review History: http://www.sdiarticle4.com/review-history/58254 

 
 
 
 

Received 03 June 2020  
Accepted 21 June 2020 
Published 01 July 2020 

 
 

ABSTRACT 
 

The aim of this article is to explain different types of immunity and discuss how the human body 
could build immunity against COVID 19. This would also serve as a guide for public health 
education on immunity in this era of COVID 19 pandemic.  

 

 
Keywords: Immunity; public health; COVID 19. 

Mini-review Article 

………… Article 



 
 
 
 

Opoku et al.;AJI, 3(1): 278-282, 2020; Article no.AJI.58254 

 
 

 
279 

 

1. INTRODUCTION 
 
Every second of day, an enemy of aggressive 
pathogens (disease causing organisms) such as 
bacteria, fungi, and viruses crowd on our skin 
and we stay remarkable healthy most of the time. 
The body seems to have evolved a single- 
minded approach to such rivals- if you are not 
with us, you are against us. To implement that 
stance, it relies heavily on the two intrinsic 
defense systems and that act both independently 
and cooperatively to provide resistance                      
or immunity against disease causing pathogens 
[1]. 

 
The above introduction therefore suggest that 
one’s immune system is very vital to fight the 
new COVID 19 pandemic. The discussion in this 
article seek to explain types of immunity and their 
application to fight COVID 19.   

 
2. IMMUNITY 

 
Immunity is defined as the body’s own ability to 
destroy pathogens or other foreign material and 
to prevent further cases of certain infectious 
diseases. This ability is of vital importance 
because the body is exposed to pathogens from 
the moment of birth. Immunitytherefore means 
being protected from something and being 
unaffected or not bothered by it. Let's say you 
have immunity to heat - this means heat can't 
bother you whatsoever - walking up to hot molten 
lava (about 2,000 degrees F!) would be no 
different than walking up to a river. Our immune 
system protects us and helps fight off disease 
causing microorganisms such as virus, bacteria, 
fungi and others [2]. Immunity has two main 
components: innate immunity and adaptive 
immunity [3]. 

 
2.1 Innate Immunity 

 
Innate immunity may be called nonspecific, does 
not create memory, and its responses are always 
the same irrespective of the target. The innate 
immune system consist of structures that defend 
body against infections and could be activated 
immediately pathogens invade the body [4]. The 
innate immune system is essentially made up of 
barriers that aim to keep viruses, bacteria, 
parasites, and other foreign particles out of your 
body or limit their ability to spread and travel 
throughout the body. The innate immune system 
consist of: 
 

2.1.1 Physical barriers  
 
Physical barriers that prevent entry of pathogens 
such as intact skin, intact the gastrointestinal 
tract, the intact respiratory tract including 
nasopharynx and cilia, eyelashes and other body 
hair [5]. 
 
2.1.2 Defense mechanisms 
 

Defense mechanismssuch as various secretions, 
mucous, bile, gastric acid, saliva, tears, and 
sweat.  
 

2.1.3 General immune  
 

General IMMUNE Responses such as 
inflammation, complement, and non-specific 
cellular responses. The inflammatory response 
vigorously brings immune cells to the location of 
an infection by increasing blood flow to the area 
[6]. 
 

2.1.4 Complement  
 

Complement system is an immune response that 
marks pathogens for them to be destroyed and 
makes holes in the cell membrane of the 
pathogen. 
 

The innate immune system is always general, or 
nonspecific, meaning anything that is identified 
as foreign or non-self is a target for the innate 
immune response. The innate immune system is 
stimulated by the existence of antigens and their 
chemical properties [3]. 
 

The innate immunity is very effective against all 
kinds of infections including viruses such as 
COVID 19. Thus people with very strong and 
efficient innate immune system could therefore 
withstand the COVID 19 infection and this 
explain why the young are not normally dying 
from the COVID 19 infection as compare to the 
aged. This is because the innate immune system 
deteriorate with ageing especially among those 
with comorbidity. The reason there is high 
morbidity and mortality with COVID 19 among 
the aged with comorbidity [6]. In addition to the 
above, the preventive measure such as face 
masks combined with other preventive 
measures, such as frequent hand-washing and 
social distancing, help slow the spread of the 
virus because they actually enforce the physical 
barrier provided by innate immunity [7]. Again the 
preventive measures help to stop the spread of 
the infection through people coming into contact 



 
 
 
 

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with defense secretion like mucus, saliva, tears, 
and sweat that may be used as vehicle to spread 
the COVID 19 from person to person.   
 

2.2 Adaptive Immunity 

 
Adaptive immunity is very specific as to its target, 
may involve antibodies, does create memory, 
and may become more efficient. Unlike the 
innate immune system, the adaptive immune 
system depend on fewer types of cells to carry 
out its responsibilities: B cells and T cells. Both B 
cells and T cells are lymphocytes that are 
produced from specific types of stem cells, called 
hematopoietic stem cells or tissues, in the red 
bone marrow. After they are production in the 
bone marrow, they need to mature and become 
stimulated [3]. 

 
When activated during an immune response, 
some B cells will divide many times and become 
plasma cells that produce antibodies to a specific 
foreign antigen. The mechanisms of immunity 
that involve T cells and B cells are specific, 
meaning that one foreign antigen is the target 
each time a mechanism is activated.  

 
Have you ever wondered how your recovery time 
for the common cold, the flu, or small infections 
seems to get shorter after you’ve been exposed 
and successfully recovered the first time? The 
adaptive immune system, also called acquired 
immunity, uses specific antigens to strategically 
mount an immune response. Unlike the innate 
immune system, which attacks only based on the 
identification of general threats, the adaptive 
immunity is activated by exposure to pathogens, 
and uses an immunological memory to learn 
about the threat and enhance the immune 
response accordingly. The adaptive immune 
response is much slower to respond to threats 
and infections than the innate immune response, 
which is primed and ready to fight at all times [8]. 

 
The adaptive immune system is exactly that - it's 
adaptive, meaning it can adapt to a specific 
threat, or antigen. For example, if the opposing 
team brings in a substitute, the entire team can 
adapt to that new substitute's unique threat. 
However, the adaptive immune system takes 
time to develop; there's a lag of sorts, meaning 
the trainer of the team needs to coach his 
players on how to adapt to an antigen, or the 
recognizable and visible aspect of a threat, like a 
bacterium's surface receptors. The good thing is 
once the players are trained well enough, they 

develop a good memory with respect to that 
threat. This means that whenever they encounter 
that substitute, or specific antigen or threat, 
again, they will know exactly what to do with it 
and will not have to waste time training for it. 
Basically, the delay is only really significant the 
first time around, not as much thereafter. All of 
this is in contrast to the innate immune system, 
which suffers no delay, has no memory and isn't 
trained to respond to a specific threat; it goes 
after everything that moves [9]. 
 
This means that for one to get immunity against 
COVID 19, the individual should be exposed to 
the virus first before the body is stimulated to 
produce antibodies against it. This may require 
the person being infected with the virus and after 
recovery the person produce antibodies for 
subsequent infections of COVID 19. On the other 
hand, one could also produce antibodies through 
COVID 19 vaccination after which could build 
resistance against the virus.    
 

3. TYPES OF IMMUNITY BASED SOURCE 
OF IMMUNITY 

 

If we consider the source of immunity, that is, 
where it comes from, we can begin with two 
major categories: genetic immunity and acquired 
immunity (Adaptive immunity) [10]. 
 

3.1 Genetic Immunity 
 

Genetic immunity does not involve antibodies or 
the immune system but conferred by our DNA; it 
is the result of our genetic makeup. What this 
means is that some pathogens cause disease in 
certain host species but not in others [11]. Dogs 
and cats, for example, have genetic immunity to 
the measles virus, which is a pathogen only for 
human. On the other hand, Mouse Leukemia 
viruses affect only mice and not human; thus 
human have genetic immunity to these viruses 
[12]. This is not because human have antibodies 
against these mouse viruses, but rather we have 
genes that are the codes for proteins that make it 
impossible for such pathogens to reproduce in 
the human cells and tissues. Monkeys have 
similar protective genes and proteins for the 
human AIDS virus and therefore HIV does not 
cause disease in these monkeys. Because this is 
a genetic characteristic programmed in DNA, 
genetic immunity always lasts a lifetime [10]. 
 

The above explanation means that some group 
of people may have this type of immunity which 
could make them build some resistance to the 



 
 
 
 

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COVID 19. The reasons black people in Africa 
and for that matter Ghana are perhaps recording 
low mortality from COVID 19.  
 

3.2 Acquired Immunity 
 

Acquired immunity does involve antibodies and 
consist of Passive immunity and active immunity. 
Acquired immunity is developed or acquired by 
natural or artificial means.  
 

3.3 Passive Immunity 
 

There are two types passive immunity which 
areNaturally Acquired Passive Immunity and 
Artificially acquired passive immunity. 
 

3.3.1 Naturally acquired passive immunity 
 

It means that the antibodies are from another 
source but naturally transmitted. One type of 
naturally acquired passive immunity is the 
placental transmission of antibodies (IgG) from 
maternal blood to fetal circulation [10]. This 
means a pregnant woman could transmit 
antibodies of COVID 19 to fetus before the baby 
is born. Such a child would be bornimmunity 
against COVID 19. The baby will then be born 
temporarily immune to the diseases (COVID 19) 
that the mother is immune to. Such passive 
immunity may be prolonged by breast-feeding, 
because breast milk also contains maternal 
antibodies (IgA). 
 

3.3.2 Artificially acquired passive immunity 
 

It immunization induced by the transfer of 
antibodies is obtained by the injection of immune 
globulins (gamma globulins or preformed 
antibodies) after presumed exposure to a 
particular pathogen. Such immune globulins are 
available for German measles, hepatitis A and B, 
tetanus and botulism (anti-toxins), and rabies. 
These are not vaccines; they do not stimulate 
immune mechanisms, but rather provide 
immediate antibody protection. Passive immunity 
is always temporary, lasting a few weeks to a few 
months, because antibodies from another source 
eventually break down [13]. 
 

With this type of immunity means that scientist 
would have develop immunoglobins to fight 
COVID 19 which may be quiet expensive. 
 

3.4 Active Immunity 
 

Acquired immunity is the production of one’s own 
antibodies and may be stimulated by natural or 

artificial means. Active immunity means that the 
individual produces his own antibodies [14].  
 

3.4.1 Naturally acquired active immunity 
 

It means that a person has recovered from a 
disease and now has antibodies and memory 
cells specific for that pathogen. Naturally 
acquired active immunity occurs when a person 
is exposed to a live pathogen and develops a 
primary immune response, which leads to 
immunological memory [14]. This type of 
immunity is "natural" because deliberate 
exposure does not induce it. The COVID 19 
patients who have been recovered from the virus 
could acquire this type of immunity and therefore 
may build resistance against subsequent 
infections of COVID 19. 
 

3.4.2 Artificially acquired active immunity 

 
It is the result of a vaccine that has stimulated 
production of antibodies and memory cells [15]. 
Artificially acquired active immunity can be 
induced by a vaccine, a substance that contains 
antigen. A vaccine stimulates a primary response 
against the antigen without causing symptoms of 
the disease [16]. 
 

For this immunity be acquired against COVID 19, 
there is the need to develop vaccine that could 
be administered after people have tested 
negative to the COVID 19.  
 

It should be noted that, no general statement can 
be made about the duration of active immunity. 
Recovering from plague, for example, confers 
lifelong immunity, but the plague vaccine does 
not. Duration of active immunity, therefore, varies 
with the particular disease or vaccine [17]. 
 

4. CONCLUSION 
 

From the above discussions it is clear that there 
are different dimensions to immunity and 
therefore various means of acquiring each of the 
immunity explained. This could be used by health 
professionals to educate the public on the 
prevention of the spread of COVID 19. 
 

CONSENT 
 

It is not applicable. 
 

ETHICAL APPROVAL 
 

It is not applicable. 



 
 
 
 

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282 

 

COMPETING INTERESTS 
 
Authors have declared that no competing 
interests exist. 

 
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provided the original work is properly cited. 

 
 

 

 
 

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