The main aim of the vaccination is to provide individual protection to the people as well as generate the herd immunity among the population in order to break the chain of transmission. For Corona, it is expected that almost 65-67% population need to have immunity to break the chain of transmission. If that be so, 89.7 Cr to 92.5 Cr population need to be immunised. Will that be possible? One may wonder. The corona vaccines are contraindicated for pregnant women (10% of all women in child-bearing age). The vaccine is not yet cleared for children and adolescent (<18 yrs forming approx. 23%). The vaccine is optional for only those who volunteer for it. It is a general feeling that about 20-25% people may not come forward for the vaccination as per the mood prevalent today. However, we don’t know if they will change their minds in the weeks and months to come. Under such circumstances, possibly all in the eligible groups of individuals will have to be vaccinated in order to achieve adequate herd immunity.
As the time passes, many questions will keep arising on the vaccination plans. Even before the vaccination drive started in India on 16 Jan 21, questions were already being raised of its efficacy and safety. In the first phase of the vaccination, 'Covid Warriors' have been prioritised. The govt and private hospitals are in the list but what about those who run their own small clinics? They don’t figure in the current list of Covid Warriors. Surely govt will have to make provision for them too. This is just one example. Many such queries are already in public domain; some being listed out here for which clear guidelines will have to be laid down: -
Should the Covid patients be vaccinated?
Should an immunocompromised patient receive the vaccination?
Should the adolescent and children on whom the Ph-3 trial have not been carried out, be vaccinated?
How many booster doses will be required if Covid19 infections continue in a nation?
What are the delayed sequele of the vaccination?
Will the vaccine be effective against the newer variants of the Corona?
Pros of the Vaccination. The strongest point in favour of the vaccination is that the individuals will get immunity and will be protected from any serious consequences of the Covid19. This wil surely reduce both morbidity and mortality of Covid19 as well as reduce the burden on the healthcare services of the nations. The other aim and objective of the vaccination is to achieve the ‘herd immunity’ to break the chain of transmission in the society. This larger aim in the national interest can be achieve only if people come forward for the vaccination.
Cons of the vaccination. In USA and Britain, many subjects receiving both Pfizer and Moderna vaccination have reported moderate to severe adverse reactions. Some had to get admitted to the hospital and one-odd have even died. In India too, mild symptoms of local inflammation at the injection site have been reported in the form of mild redness, pain, swelling and mild fever too. Three subjects have died after few days of vaccination by heart element unrelated to the vaccination. Indian vaccines have fewer side-effects. Nonetheless, the apprehensions are there but less. There are however, many questions in the minds of the people some of which can be answered but many not…at least at this time. They include the followings: -
Could the vaccine be injected to children & adolescents <18 yrs and elderly >55 yrs age as those age groups were not included in the Ph-3 trials? Report released by the MS, CMC Vellore dated 11 Jan 21 indicates so. It is felt that those above 55 yrs of age who are clearly at the higher risks of Covid19, could be vaccinated with inferences drawn from the study. Many may also feel it reasonable enough to vaccinate the children above 12 yrs of age. However, these are “inferences drawn” and not the actual studies. Since children <12 yrs may need a smaller dose, they are nor recommended to be vaccinated. As such they are not at higher risks of Covid19.
What if immunity is not adequate? There could be Covid19 infection in spite of vaccination. However, the severity of such vaccination will be less. Chances of them spreading infections to others are remote.
What if another variant of virus mutate? This is a genuine question in everyone’s mind. The scientists as yet, do not have a clear answer. There are hypothetical postulations that the vaccines against the Corona Virus should be effective against the Spanish, UK or the African variants of the Viruses. The same are the expectation for the vaccines against the German variant detected a couple of days back.We don’t know if altogether a different mutant strain of Virus will strike us in the coming weeks and months. There are claims and counterclaims about the efficacy of one or other vaccine candidates against the mutant strains of the virus but there are no confirmatory data. These claims are driven more for commercial considerations than the scientific proof. In general, it is expected that most if not all vaccines available as on the date, are also effective against the mutant strains though with somewhat lesser efficacies.
Will all vaccines be equally effective as a “booster dose” among the subjects who have recovered from Covid19? We don’t know with precision. We also know that all Covid19 patients have varying level of antibodies. Whether the particular Vaccine candidate will boost an identical antibody response, we don’t know. It is expected that all vaccines having whole SARS nCoV2 virion, attenuated or killed, should have identical antibody response and serve as a perfect booster dose for them. What about the others? Will other vaccine candidates require two doses in Covid19 recovered patients too? The scientists will have to find the answer.
Could the Vaccine cause serious antigen-antibody reactions among the Covid19 patients who have recovered from the infection? We don’t know for sure. Same is the answer for them who have received the convalescent serum of the Covid19 subjects after their recovery. Theoretically many of the ‘Corona Warriors’ are expected to have suffered asymptomatic and undetected Covid19. They may be having Corona antibodies in their blood. Such people, if given vaccine, could theoretically develop an Antigen-Antibody reactions of various grades incl that of anaphylaxis. Here, we may draw inferences from the Oxford-AstraZeneca Vaccination among the British for over 2 weeks now, where no serious antigen-antibody reactions have been reported. Hence, theoretical assumption of higher or serious antigen-antibody reactions appears to be unfounded. Indian roll-out of the vaccination will throw more light on this aspect.
The Indian vaccination program is massive. In the initial few days only, enough data is available about the safety of the vaccines…esp among the frontline workers, many of whom may have varying levels of Corona antigen in their blood. They are theoretically expected to manifest more allergic reactions. The next groups of the recipients of the vaccines that will incorporate the elderly and those having co-morbidities, and later... the general population, who are likely to have much less of the allergic manifestation as compared to the frontline workers.
While the vaccines are coming to the market, commercial rivalries too are on. China is understood to be running a smear campaign against the Indian vaccines esp in Africa. On the other hand, Indian Govt is trying to fulfil its obligations to provide the vaccines in the neighbourhood…to Nepal, Bangladesh, Sri Lanka, Maldives Seychelles Islands and Afghanistan. PM Modi had made a commitment in the UNGA of providing the vaccine to the world and stands firm on it. DG, WHO Dr Tedros has warned of vaccines not being available to the smaller and poorer nations. India is trying to do its best to fulfil the obligations.