My friends are already asking me why people around the world are afraid of the vaccine for COVID-19 that is being developed. Many people know that vaccines are good stuff because they have protected billions of humans against diseases. They just cannot understand why the same is dreaded around the world to the extent that there has been a push and pull on where potential vaccines should be tested in a clinical trial.
Bill Gates himself despite being the proponent and the financier of vaccine research does not want the testing or clinical trials were done on American people – his country. Here I explain why this fear by briefly discussing the different types of vaccines and their implications on safety and/or effectiveness particularly when things go haywire.
What are Vaccines?
In immunology, vaccines are defined as antigens (Proteins) which when introduced into the body are detected as foreign material by the body. Consequently, the body fights them by producing antibodies against them. Then the body remains with a memory that these antigens were once detected.
The memory components (E.g. Antibodies) then attack the natural infective organism if it strikes in the future. The most important aspect of vaccines is that they must not cause disease themselves. There are different types of vaccines which include live-attenuated vaccines, inactivated vaccines, subunit, recombinant, polysaccharide, and conjugate vaccines, and toxoid vaccines.
These vaccines are the real disease-causing organism (would be SARS-Cov-2, in the case of COVID-19) that has been weakened (Attenuated). It is then introduced to the body of a disease-vulnerable person and the immune system responds by producing very effective long-lasting protection.
The limitation of this type is that they can revert to the original organism and cause disease (In this case COVID-19), particularly if not stored properly in the cold chain – refrigeration. This, I believe is what causes fear because if masses are vaccinated to achieve herd immunity whether during trial or immunization programs, then it can be disastrous if the same fails in this manner.
Here, the vaccine is produced by killing or inactivating the disease-causing organism using heat and then introducing it to the body of a disease-vulnerable person. This type of vaccines requires several booster doses because it’s protection is short-lived.
Subunit, recombinant, polysaccharide, and conjugate vaccines
These types of vaccines do not use the entire organism but some parts. These parts could be some surface proteins, some surface carbohydrates or the outer cover of the virus. These parts are therefore the antigens that are used as vaccines. These too need booster doses from time to time giving them a limitation.
Toxoids are the harmful products of micro-organisms. When introduced into the body, they are recognized by the immune system which produces antibodies against these parts. When these parts are targeted by the immune system, then the whole virus or other organisms will be eliminated.
One may think that this can’t work but think about someone who targets your heart or brain and not your whole body, with an intention of killing you. Would, you not succumb in the long run? But a limitation is that they also need several booster vaccines for effectiveness.
Why the fear then?
You will realize that out all the types of vaccines we’ve analyzed above, the best in terms of being long-lasting and requiring no boosters are the live-attenuated vaccines. The majority of vaccines produced against viruses are of this type.
Therefore an effective COVID-19 vaccine could be of this type as well. I am sure you can remember their limitation as discussed above – that they may revert to the original organism and cause disease. This depends on whether the cold chain storage is maintained from the bench side (where produced) to the bedside (Where immunization is done).
Given the severity of COVID-19, that is why people are afraid. However, if all the storage rules are strictly adhered to, then there can be no problem.