Explainer on how COVID-19 Vaccines are Developed

Prof. Walter Jaoko

Professor of medical microbiology and tropical medicine, Director KAVI Institute of Clinical Research, University of Nairobi

There are different ways of developing vaccines. You can weaken a virus, so it is still alive but is weakened, that is what we call attenuation. Therefore, it cannot cause disease in a human being. But when somebody is given the vaccine, the body stimulates responses thinking that it has become infected and those antibodies and cells are, therefore, ready in the event that you face the real virus.

Secondly, you can take just the portion of the virus, what we call the spike protein, and develop a vaccine out of it. The portion that you are taking is what is described as the plasmid (fingerprint of the virus). So, when the body sees that plasmid at the surface, it thinks it has seen the virus and therefore produces responses to fight it either as antibodies or as white blood cells.

The third way of making a vaccine, and this is what is being used largely in Africa, is called a vectored vaccine, where you take the plasmid and you put it in another vector, which is a weakened virus that does not cause infection in human being, that makes the body recognize that plasmid much faster and in a robust way. Therefore, the immune responses are generated in larger quantities and faster than if you use a plasmid.

The final one, which we still don’t have in Africa but few countries are using it, is a new technology called the messenger RNA technology. This is what is used in some vaccines like Moderna and Pfizer vaccines, where you take the message that the virus uses to prepare spike protein and that is what you inject into a human cell. The human cell reads that message, prepares this spike protein on its surface and then the same human being’s immune response recognizes that protein and therefore produces antibodies and white blood cells to fight the COVID virus. So, the body is therefore protected that way.






YouTube https://youtu.be/71zI7VV4pVY

Get in Touch


Latest Posts

How does IPCC work?

Dr. Joseph Nzau Mutemi, one of the Lead Authors of the just-released 2021 Intergovernmental Panel on Climate Change (IPCC) report and Scientist at the...

Top scientist urges Kenya to take new approach to regulating gene editing crops

Subjecting Kenya’s gene-edited crops to the same regulations as those developed through genetic modification could unnecessarily slow their release to farmers and consumers, warned...

Press Release: Kenya Should not Regulate Genome-edited Crops as Genetically Modified Crops, Expert Says

Naivasha, 31st August, 2021-With the increase in population and demands for more food, African countries are looking for ways of boosting food production. This...

Explainer on Covid-19 Vaccines improving Surfactant Levels in the Lungs

Prof. Barack Abonyo Prof. Medical Physiology and Registrar Planning, Partnerships, Research and Innovation, Kibabii University, Kenya "Vaccines improve the level of surfactant. Vaccines are meant to...

SPECIAL GLOBAL MEDIA BRIEFING Topic: Getting your head around the vaccine data

Organized in collaboration with the Australia, New Zealand, UK, USA, Germany, Japan, Israel, Taiwan, Philippines, Thailand, Singapore, Austria, France, Indonesia and Hong Kong media...