Before considering should we go ahead with COVID-19 vaccine? Let us first understand “How are vaccines made?” Let us understand “How Are Vaccines Made Against Viral diseases?”
Several methods are used to make vaccines against viral diseases. Let us examine their strengths and limitations one by one:
Using “Weaken” virus
Viruses are weakened so they reproduce extremely poorly once inside the body. Viruses usually cause disease by rapidly reproducing themselves many times in the body normally thousands of times during an infection. Whereas, weakened vaccine viruses usually reproduce fewer than 20 times hence do not cause disease. However, this much viruses are enough to induce “memory B cells” that protect against infection in the future. The vaccines for measles, mumps, German measles (rubella), rotavirus, oral polio, chickenpox, and influenza (intranasal version) vaccines are made this way. The advantage of live, “weakened” virus vaccines is that one or two doses provide usually life-long immunity. The limitation of these vaccines are usually cannot be given to people with compromised immune systems (like people with cancer or AIDS).
Using Inactivated virus
In this method, viruses are completely inactivated (or killed) with a chemical. These inactivated virus cannot reproduce itself or cause disease. Because the virus is still “seen” recognised by the body, cells of the immune system that protect against disease are generated. The inactivated polio, hepatitis A, influenza and rabies vaccines are made this way.
Benefits to this process is:
• The vaccine cannot cause even a mild form of the disease that it prevents
• The vaccine can be administered to people with compromised immune systems.
However, the limitation of this approach is that it typically requires several doses to achieve immunity.
Using a part of the virus
In this method, just one part of the virus is removed and used as a vaccine The vaccine is composed of coat-protein that covers the virus DNA/RNA. This strategy can be used when an immune response to one part of the virus (or bacteria) is responsible for protection against disease. The hepatitis B, shingles and human papillomavirus (HPV) vaccines are made this way. Advantages of this type of vaccines are having long-lived immunity after administering first does followed by a booster doses.
These vaccines also can be given to people with weakened or compromised immunity.
Useing part of the bacteria
Some bacteria cause disease by making a harmful protein called a toxin. Several vaccines are made by taking toxins and inactivating them with a chemical (the toxin, once inactivated, is called a toxoid). By inactivating the toxin, it no longer causes disease. The diphtheria, tetanus and pertussis vaccines are made this way. Another strategy to make a bacterial vaccine is to use part of the sugar coating (or polysaccharide) of the bacteria. Protection against infection by certain bacteria is based on immunity to this sugar coating (and not the whole bacteria). However, because young children don’t make a very good immune response to the sugar coating alone, the coating is linked to a harmless protein (this is called a “conjugated polysaccharide” vaccine). The Haemophilus influenza type B (or Hib), pneumococcal, and some meningococcal vaccines are made this way.
Just like inactivated viral vaccines, bacterial vaccines can be given to people with compromised immune systems, but often require several doses to induce adequate immunity.
Using genetic code (DNA, mRNA, or vectored viruses) for part of the virus
Using this strategy, the person who is vaccinated makes part of the virus. The vaccines for COVID-19 are made this way. The vaccine contains messenger RNA (mRNA) (Ref. 3), which is the code, or blueprint, for the spike protein of the SARS-CoV-2 virus. The vaccinated person’s muscle cells use the blueprint to make the spike protein from the surface of the virus. Once the immune system realizes this protein is “foreign,” it creates an immune response against it, including immunologic memory, so the next time, the person is exposed to the virus, the immune system is ready to respond rapidly. Similar to vaccination strategies that inject parts of a virus directly, this strategy can be used when an immune response to one part of the virus is capable of protecting against disease. These vaccines can be given to people that are immune-compromised but require two doses to be protective.
-Listen to Dr. Offit explain mRNA vaccines in his short video (Ref. 3)
DNA vaccines deliver the genetic code from which mRNA is made. The mRNA then serves as the blueprint for making the viral protein, and the immune system, recognizing it is “foreign,” responds to protect the body and create immunologic memory. Currently, no DNA vaccines are commercially available (Ref.2).
-Listen to Dr. Offit explain DNA vaccines in his short vedio (Ref. 2)
Another way to deliver the gene that codes for the coronavirus spike protein is to put that gene into a virus that can’t reproduce itself but can still enter cells and deliver the needed gene. This strategy is being used in so-called replication-deficient human or simian adenoviruses. Although adenoviruses can cause disease in people, these vectored viruses are engineered so that they can’t cause disease.
In India, we are listening about the three vaccines and their trials for approval. The nature of these vaccines are:
Oxford–AstraZeneca COVID vaccine
The vaccine, which is being co-developed by BioNTech in Mainz, Germany, consists of molecular instructions — in the form of messenger RNA — for human cells to make the coronavirus spike protein, the immune system’s key target for this type of virus.
Pfizer-BioNTech COVID-19 Vaccine
It is also a mRNA vaccine. Disadvantage of this vaccine it it require -70° C for storage.
Bharat Biotech’s “Covaxin”
Covaxin is an inactivated vaccine developed from an Indian strain of the novel coronavirus isolated by NIV. This can be stored in 5-8° C. That is the advantage over other two vaccines. In addition it is cost effective.
Questions remain unanswered: 1. One key unanswered question is how long the vaccine’s effectiveness will last? Experts think that “Right now, we need a vaccine that works,” even if it works for only a few months or doesn’t stop transmission. “That’s what we need in order to get half-way back to normal. Should WE go ahead with Covid-19 vaccine?
Vaccines have played major role in preventing life even before COVID-19. Many viral diseases have been eradicated like small pox, polio, through vaccines. So there is no doubt that vaccines are important for saving lives. As far as vaccine for COVID-19 is concerned questions are raised because it is developed very fast. Normally, a vaccine development takes about 7-8 yrs for public use. But when it is matter of life or death you have to save life first. One has to opt for “Desperate time, desperate measure.”. Some of the opposition leaders with their uninformed are trying to implant doubt in the mind of common scientifically less informed people about the safety ignoring the decision of the best brains of medical science.
However, I would remind the Indians that Ayurveda has the knowledge but that has not been given a level playing field to have a say in the creation or implementation of the immune boosters for COVID. The wisdom in Ayurveda that we are a microcosm of the macrocosm is not practiced or understood in the society at large. So just looking at the need of the hour and not looking beyond, is not going to work. If not COVID something else will crop up tomorrow. We have experienced such outbreaks like HIV, SARS, MARS and now COVID. Short term view will hurt us in long term. I wish to end this blog with the Vedic mantra chanting:
ॐ असतो मा सद्गमय । तमसो मा ज्योतिर्गमय । मृत्योर्मा अमृतं गमय । ॐ शान्तिः शान्तिः शान्तिः ॥
Meaning: Lead us from the unreal to the real Lead us from darkness to light Lead us from death to immortality Aum peace, peace, peace!
And hope that our policy makers and opposition leaders will move from darkness to light and take informed decision in the in the interest of saving life which is prime important at the moment than politics. Jai Hind! Satyabrata Maiti
Disclaimer: This article has been prepared with information drawing from various sources: research papers, websites, text books, video resources and no part of this is claimed by the author as his original work.
References
1. https://www.nature.com/articles/d41586-020-03326-w
2. https://www.chop.edu/centers-programs/vaccine-education-center/video/how-do-dna-vaccines-work
3. https://www.chop.edu/centers-programs/vaccine-education-ce
54500cookie-checkShould WE Go Ahead With Covid-19 Vaccine?
