The internet is awash with disinformation about Covid-19, and the vaccine, yet the pandemic has affected tens of millions of people worldwide.
The effects of the coronavirus, declared a global pandemic by the World Health Organisation [WHO] in March 2020, have had overwhelming health, economic, and social consequences.
Now more than ever, there is an urgency for safe and effective prophylactic vaccines across the globe.

What you need to know
• Covid-19 vaccines are safe and effective
• Normally, it would take two weeks after vaccination for the body to build immunity against the virus that causes Covid-19
• The vaccine will not make you sick with Covid-19 as it does not contain live virus
• Sometimes vaccination can cause symptoms, such as fever, which is normal and a sign that the body is building protection against the virus that causes COVID-19
• Getting the vaccine will not result in a positive COVID. However, if your body develops an immune response, you may test positive on an antibody test. Antibody tests indicate you had a previous infection and that you may have some level of protection against the virus

How the immune system fights against infection

Generally, when germs, such as the virus that causes Covid-19, attack our bodies, they multiply. This is what is called infection, which causes illness. The body’s defence uses several tools to fight infection.
Blood contains red cells, which carry oxygen to tissues and organs, and white or immune cells, which fight infection.

Different types of white blood cells fight infection in different ways:
Macrophages are white blood cells that swallow up and digest germs and dead or dying cells. The macrophages leave behind parts of the invading germs, called “antigens”. The body identifies antigens as dangerous and stimulates antibodies to attack them. These are the
B-lymphocytes are defensive white blood cells. They produce antibodies that attack the pieces of the virus left behind by the macrophages.

We also have the T-lymphocytes which are another type of defensive white blood cells. They attack cells in the body that have already been infected.

The first time a person is infected with the virus that causes Covid-19, it can take several days or weeks for their body to make and use all the germ-fighting tools needed to get over the infection. After the infection, the person’s immune system remembers what it learned about how to protect the body against that disease.
The body keeps a few T-lymphocytes, called “memory cells,” that go into action quickly if the body encounters the same virus again. When the familiar antigens are detected, B-lymphocytes produce antibodies to attack them. Experts are still learning how long these memory cells protect a person against the virus that causes COVID-19.

Types of Vaccines
In essence, Covid-19 vaccines equip our bodies to develop immunity to the virus that causes Covid without us having to get the illness.
There are presently three main types of Covid-19 vaccines that are authorised and recommended or undergoing large-scale clinical trials in the United States.
Below is a description of how each type of vaccine prompts our bodies to recognize and protect us from the virus that causes Covid-19.

mRNA vaccines contain material from the virus that causes Covid-19 that gives our cells instructions on how to make a harmless protein that is unique to the virus. After our cells make copies of the protein, they destroy the genetic material from the vaccine. Our bodies recognize that the protein should not be there and build T-lymphocytes and B-lymphocytes that will remember how to fight the virus that causes Covid-19 if we are infected in the future.

Protein subunit vaccines include harmless pieces (proteins) of the virus that causes Covid-19 instead of the entire germ. Once vaccinated, our bodies recognize that the protein should not be there and build T-lymphocytes and antibodies that will remember how to fight the virus that causes Covid-19 if we are infected in the future.

Vector vaccines contain a modified version of a different virus than the one that causes Covid-19. Inside the shell of the modified virus, there is material from the virus that causes Covid-19. This is called a “viral vector.” Once the viral vector is inside our cells, the genetic material gives cells instructions to make a protein that is unique to the virus that causes Covid-19. Using these instructions, our cells make copies of the protein. This prompts our bodies to build T-lymphocytes and B-lymphocytes that will remember how to fight that virus if we are infected in the future.
Some Covid-19 vaccines require more than one shot.

Tanya Nyathi is medical editor for FCB Health, a top Pharma Agency in New York. She holds an M.Phil in Communication Management from University of Pretoria in South Africa and an M.Sc in Journalism at Columbia University in New York. For seven years, she has been a regular health and science contributor to African news publications with a global audience.