Manoj Pandey*
A number of Covid 19 vaccines have come out and some are in the pipeline. According to the latest data on vaccine development against SARS-Cov-2, the virus that causes Covid 19, 91 vaccines are in active stages of development and nearly 20 out of them should be available in the next three months.
We have discussed a number of concepts relating to vaccination in an earlier article in this very column. In the present one, let’s specifically examine the claims and counter-claims about what these vaccines can and will do.
Can vaccines give you Covid 19?
No. The vaccines are either very weakened forms of virus/ dead virus/ parts of virus/ m-RNA produced by virus/ virus proteins. They do not contain active virus that can infect a human being.
Does vaccination mean people get immunity against the virus?
Immunity means the ability of a living being to resist an infection by developing a biochemical mechanism against the pathogen. Vaccines are one way to induce immunity. Most people have natural immunity to a large number of pathogens and they also get immunity after infection.
No vaccine is 100% effective. A vaccine that is 95% effective is likely to induce enough immunity in 95 of the 100 persons to whom the vaccine is given.
Covid vaccines are being developed fast. Does that mean, all required precautions are not taken and vaccines are inherently hazardous?
Covid vaccines have indeed been developed very fast. We are yet to have a vaccine against HIV (which is supposed to cause AIDS) though the virus has been in circulation for decades.
However, there is no report from anywhere that necessary protocols are being given a go by. The vaccine developers cannot afford to slip, because the vaccine will be exposed immediately.
The vaccines that have overtaken others are m-RNA vaccines; and one big reason for their fast development is that genetic splicing and associated technology used in development of this type of vaccines takes less time.
The fast pace of development of Covid vaccines has also been possible by overlapping different phases of clinical trials, availability of volunteers in large numbers, and cooperation among developers, scientists and authorities.
Mass-scale vaccine production is being fast-paced by producing them in advance (but the vaccines are released for use only after final approval).
Besides strict monitoring by institutions, governments and the public too are vigilant. We have seen that when a vaccine is prematurely promoted as successful, it gets no buyers until all trials are completed.
Are the vaccines full of side effects, some of which are very serious?
As we know, vaccines are external biological substances. The body has a mechanism to react to such objects when they are directly injected into the system. Since vaccines are weakened forms of virus or parts of virus genome or proteins, they create sufficient reaction so that the body is warned about the danger but does not react beyond a point. The known side effects of Covid vaccine are natural and minor, and they disappear in a few hours/ days. These include localized muscle ache, headache, fatigue, mild fever and discomfort.
Theoretically, due to some factors (genetic make-up of a human being is a major one), bodies of a few vaccine recipients can react too much and cause serious side effects. That is why vaccines are tested on thousands of volunteers of different races, genders, age, etc before they are marked safe.
Even the vaccines already authorised for emergency use or full use in one country are again examined in other countries to take care of racial and other variations.
The two vaccines already being administered in the US and the UK (one developed by Pfizer and the other by Moderna) have not shown any serious side effects. Yet, those allergic to injections etc have been advised to discuss the likely adverse effects with their doctor before going for vaccination. Similarly, if one develops side effects that are too discomforting or painful after the first dose, he should check with the doctor before getting the second dose.
Some pain and discomfort, and possibly a mild fever, after vaccination are the signs that the vaccine is working.
Can vaccines based on RNA alter one’s DNA? Even Brazil’s President has indicated that. Is that so?
Use of a type of RNA (called m-RNA) in production of vaccines is an advanced technique. Instead of injecting a part of virus or its protein, a strand of this RNA is injected into the human body to produce a reaction.
Genetic material entering human bodies from pathogens is normal in any infection. So, in that sense, even injecting DNA from a virus is not unusual. However, m-RNA is not part of the genetic material of the virus. It cannot force the human genetic material in any way other than asking it to produce certain viral proteins. It is active only outside the nucleus of a cell (where DNA is located) and can only produce a protein, not genetic material.
What percentage of the population should get vaccinated so that others, who are not infected, remain safe?
Nobody can be termed ‘safe’ from an infection unless his body has developed/ has the capacity to develop antibodies against that infection. So, even if 99% of the population is vaccinated or gets immunity due to natural infection, the rest 1% are vulnerable.
However, as explained in this article on herd immunity, when a significant majority of the population has immunity, the infection gets stonewalled against spread to the ones not infected. Thus, if a population already has some 25% people who have tested ‘positive’ for Covid 19 and have recovered (as is the case in urban India) and another 45% – 50% are vaccinated, the population will have herd immunity to the extent that the disease spreads very slowly among the rest of the population.
Do vaccines help when someone is already infected?
If one is already infected and is still ‘positive’ for Covid 19, the vaccine will not help.
If someone was ‘positive’ for the disease and has recovered, sufficient data is not there at present for a definite answer whether he must get vaccinated. Experts advise that one should get vaccinated after about four months of infection to avoid getting infected by the disease the second time.
Do all vaccines need to be stored and transported at very low temperatures?
Different vaccines need different temperatures for storage and transportation. The two vaccines mentioned here (by Pfizer and Moderna) are m-RNA vaccines and need very low temperatures for their storage and transportation.
Are two doses of vaccines required to be given?
The two vaccines discussed here need a second dose. For Pfizer vaccine, the second dose is given after 21 days and for Moderna vaccine, after 28 days.
Is it a fact that people will not need to bother about social distancing once most people are vaccinated?
No way. One must continue to take precautions.
Firstly, because all aspects about the virus are not yet known. A ‘negative’ or vaccinated person could still be carrying virus to infect others.
Secondly, remember the percentage of efficacy of vaccines? If a vaccine is 95% effective, it could leave out 5 out of 100 without immunity. These are potential patients or carriers.
Thirdly, the vaccinated person is prone to get infection the second time if he does not take precautions.
Should one get vaccinated with more than one vaccine to get better protected?
It is too early to tell how different vaccines would react. However, logically speaking, taking two types of vaccines may be safe but might not give additional benefit in terms of immunity.
A related point to be noted is that different vaccines are not interchangeable. One cannot go for the first dose of one vaccine and the second dose of another.
Are the vaccines effective only for about four months?
The research is on, yet. In a number of infected people, a second infection has been reported after three or four months and the second infection has usually been milder. Perhaps in such cases the first infection was too mild to produce enough antibodies.
Vaccine developers will be looking for ways to ensure sufficient immunity, and, if required, to ‘boost’ the immunity so that such recurrences do not take place.
Many new strains of coronavirus are emerging. Will the vaccines become useless against new strains?
That is a concern.
The mutations recorded so far seem to be such that the vaccines that are approved or are in final stages will be effective against all variants. But the way viruses tend to mutate, it is a real possibility that vaccines developed against existing variants may not be effective against new variants.
As was expected, it is reported that vaccine developers have started testing their vaccines for new variants.
If Covid 19 kills only 1% – 3% people and vaccines are only 95% effective, vaccination does not make sense, does it?
This fallacy is seen circulating on WhatsApp of late. Both the figures given here are correct but the conclusion is false.
Please read the data again: Covid kills only 1-3% of the people who are infected. The vaccine does not produce immunity in 5% of the people in the vaccinated population.
So, in a population of 100,000 without vaccination and with low natural immunity (chances of all people getting infected one day or the other), there is a chance of 1000 – 3000 persons eventually dying out of Covid 19. After full vaccination, the number of people likely to die of Covid 19 comes down to 50 – 150 (5% of 100,000 get infected, out of which 1% – 3% die).
Are there separate types of vaccines for small kids?
At present, the priority is on development of vaccines for people aged 16 or more, because small children are found to be naturally better protected against Covid 19 infection.
However, over one year or even earlier, separate formulations of the same vaccines or new vaccines will come in the market specifically for kids.
Does vaccine development involve use of pork?
Vaccines need a stabilizing agent, usually gelatine. Gelatine is used widely in pharmaceuticals in different ways.
It is a fact that this substance is produced from the collagen tissue of chickens, fish, pigs and cattle. However, the gelatine used in the development of vaccines is highly purified.
The stabilizer for a vaccine is chosen at an early stage of its development. If gelatine were to be replaced with some other product, it might take a long time to develop a new vaccine.
Can vaccine injection be used to inject a chip in the human body?
Looks preposterous!
This conspiracy theory seems to have become popular on social media after Bill Gates advocated giving a digital certificate to those who get vaccinated.
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About the author: This article has been contributed by Manoj Pandey. He does not like to call himself a rationalist but insists on scrutiny of apparent myths as well as what are supposed to be immutable scientific facts. Please don’t take the views of the author as the views of Raag Delhi.
बहुत रोचक,बहुत प्रभावी