COVID-19 Vaccine

COVID-19 Vaccine: How Vaccines Work

Vaccines save millions of lives every year, but how do they work?

Think of the body as having a defense mechanism to fight off diseases called an immune system. The immune system is an army that has several specialized troops that provide specialized services in fighting off the enemy (disease).

Breaking it Down

COVID-19 Vaccine

A vaccine helps the body to fight disease-causing organisms by triggering the body’s army, the immune system, which is designed to defend the body by attacking and destroying the disease-causing organisms. The disease-causing organisms can be bacteria, viruses, parasites, or fungi that attack the human body and cause illness.

How Vaccines Work

When vaccines are introduced in the body, they mimic some parts of the disease-causing organisms, called antigens, just enough to trigger the body’s immune system to produce protective substances called antibodies which fight the antigens without causing the actual disease.

The body also produces some special cells that will remember the antigens associated with the disease called ‘memory cells’ which can quickly recruit antibody-producing cells and train them to produce antibodies against the disease, at a faster rate than the disease can multiply. The antibodies, therefore, help the body to overcome the disease-causing organism before it can cause illness.

Infection in a Vaccinated Individual

COVID-19 Vaccine

When a vaccinated person is infected with the actual disease-causing organism, the memory cells remember the disease-causing antigens and quickly call upon the disease-fighting antibodies to fight off the disease. They do this by triggering an immune reaction, similar to what was experienced during vaccination, and the disease is not able to multiply fast enough to overcome the body’s defense system. The disease is therefore overwhelmed by the body’s defense mechanism.

Diseases that have been conquered through Vaccination

Children especially those under one year, are vaccinated against several life-threatening diseases, such as polio, measles, meningitis, pneumonia, diphtheria, whooping cough.

How are vaccines administered?

COVID-19 Vaccine


Some vaccines are given orally, and others through injection to several parts of the body, as recommended by the vaccine developers. Vaccines may be administered once or several times, based on evidence on the number of doses that will trigger an adequate immune response to protect against disease.

Selection of Vaccines

Vaccines must be approved by the WHO and in the countries where they are administered by passing stringent international standards on safety and effectiveness. Vaccines are selected based on whether they are effective in preventing disease, and whether they are safe for use by individuals. Families and communities.

Vaccines are disease specific

The human body mounts an immune response by producing unique antibodies to fight against antigens caused by specific diseases Each disease-causing organism produces specific disease-causing antigens in the body which trigger the immune system to produce antibodies. Specific vaccines, therefore, are produced against each of the serious life-threatening diseases, including COVID-19.

COVID-19 Vaccine

COVID-19 Vaccine

Amid the COVID-19 pandemic, scientists worldwide are working very hard to develop vaccines against COVID-19, as part of the pandemic response. More than 50 potential COVID-19 vaccines are under development, and the global health community is hopeful that a safe and effective vaccine will soon be available to assist in efforts to control the pandemic.

People most at risk of the disease will be prioritized for vaccination, such as front-line health care workers, older adults, and those with underlying conditions that make them more vulnerable to contracting COVID-19.

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Dr. Grace Ikahu Muchangi has been working in the area of public health in strengthening of health systems to improve health outcomes since 2008.
© 2018 Grace Ikahu , All Rights Reserved
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