What are Vaccines and How Will they Work Against Coronavirus


What are Vaccines and How Will they Work against the Coronavirus.

Vaccines are most often used to prevent infectious diseases, although they have also been used to treat certain illnesses including cancer. Most vaccines are given as “shots” while some such as the polio vaccine are given as drops, to be taken by mouth.





The classic example is the Polio vaccine that is used to prevent Poliomyelitis, a paralyzing disease of the nervous system.

To understand how vaccines work, one needs a basic understanding of the immune system. Almost all living organisms are endowed with an immune system that protects them from foreign invaders such as bacteria and viruses. Even tiny bacteria can become infected with viruses. 

When a germ enters our body, it is recognized as “foreign” by the immune system and efforts are mounted to get rid of this invader. Drug manufacturers use this property to develop vaccines. There are many ways by which the tell-tale information of the invading germ (called antigen) is used to inform the immune system and manufacture a vaccine. 



In the case of coronavirus, such tell-tale markers (antigens) may include the proteins on its surface, the molecules on its spikes or the pieces of its RNA (ribonucleic acid) and use them as the antigens. In other cases, the whole virus can be used as the  source antigen. In such cases, scientists kill (in-activate) the virus or maim it (partially in-activate) so that even alive, it is unable to cause infection. The Tetanus vaccine is made neither by a piece or the whole virus but by using the toxin (the harmful molecule), as the antigen.

Once presented to the body, the immune system recognizes these antigens as foreign molecules and alerts special cells (macrophages, lymphocytes, plasma cells) that belong to the immune system. Presented with the antigen, these cells  make special proteins called “antibodies” designed to ward off the invading germs. The antibodies that are produced immediately (within days and weeks) belong to the IgM class of immune proteins (immune globulins). In due course, the immune cells produce large quantities of antibodies of the IgG class that can stay in the body for a long time, sometimes for the rest of our lives. Besides the cells that recognize the invaders, alert others and those that manufacture the antibodies. immune system also has special type of immune cells called memory cells. The cells commit the information of the specific to their memory. Before these cells die, they pass on this information to their daughter cells. If any time in the future, even decades later, that particular germ invades the body, the memory cells spring into action and based on the information stored in their memory, manufacture antibodies to prevent the infection from occurring again.

Occasionally the immunity falls off. This may be due to poor quantity and quality of the stimulating antigen or may be due to the defective immune system.  In such cases vaccination has to be repeated to boost the immunity and preserve the protection against infection.

Viruses and germs, although tiny, are very clever. At times they mutate (make small changes in their RNA or the DNA), making it difficult for the memory cells of the immune system to recognize them. That is one reason why we need flu shot every year because the influenza virus keeps changing its structure and keeps mutating.

The race is on to develop the vaccine for the COVID-19 virus. Many companies are testing different antigens such as the capsule of the virus, its spikes or the RNA segments to inoculate test animals and determine which will be best candidate antigen. Once that is done, an effective way to present that antigen to the body’s immune system will be perfected. The human trials will then follow to assess the efficacy and safety of the potential candidate vaccines and present the data to the FDA. The winners will be awarded the manufacturing license to mass produce the vaccine and bring it the market. 

We just hope that such a day comes soon and importantly, the virus does not mutate by then.
Lets pray that we win over this contagion very soon. Amen.

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