Amid a race to obtain the most acceptable COVID-19 vaccine, buzz mills are also spreads with one assumption or the other. A significant part of the news we read and hear in the background of the pandemic is hypothetical. For example, when US president Mr.Trump announced in March that hydroxychloroquine was ‘a game-changer’, large areas of the world population misinterpreted it for a reality, while it was pure speculation. The amount of struggle and money that was finally wasted in establishing this belief wrong could have been better used during the pandemic.
Although it might be beneficial while preparing research studies, assumption is often fouled with prejudice and emotion. Also, in the fast-changing domain of vaccines, speculation is uncontrolled. This has resulted in unreasonable worry and unrealistic expectancy. The purpose of this article is to explain the facts about vaccines with minimal vocabulary, splitting the knowns from the unknowns to the dimensions conceivable. As science persists to progress, some of this knowledge is subject to shift.
1. Vaccines cannot compare with a light switch that turns off the illness. Even after they become accessible, social distancing efforts will persist until the pandemic subsides. In other words, vaccines denote only one element of the anti-pandemic approach.
2. Efficacy is the percentage reduction of disease attended in the vaccine group, likened to the placebo group, calculated under perfect circumstances. This will be higher than persuasiveness, which counts the same output in ‘real-world conditions’- that is outside of a carefully managed clinical preparation.
3. Efficacy estimated within the first two months after completing vaccination will be consistently elevated due to high antibody levels. Preliminary results have reported 62-95% effectiveness. It is necessary to see how these numbers bear up in the 6th, 12th, and 24th months, as antibody titers slowly decrease.
4. There is plenty of discussion about what must be carried as the end-point to be counted as evidence of the effectiveness of a COVID vaccine. Pfizer, Moderna, and AstraOxford picked symptomatic COVID-19 as the ‘primary endpoint’. This indicates that asymptomatic conditions are not calculated as a prior endpoint. The criteria for interpreting symptomatic COVID-19 are different for each vaccine. Other conceivable primary end-points that could have been used include the total number of all infections (including asymptomatic SARS-CoV-2 infection), number of deaths, or number of people demanding ventilator support.
Determining a primary endpoint in a clinical practice is rather like selecting a single feature of a car model to compare between various manufacturers. Some people might examine at dependability; a few will favor to compare engine performance in horsepower and yet others may analogize mileage.
5. The method of carrying out a vaccine applies building the vaccine and then experimenting its protection as well as efficacy. While technology allows more rapid development of a vaccine, unfortunately, we cannot accelerate the time of observation. Safety assessment is done over a period of time, and this cannot be shortcircuited. This is the reason why the FDA has asked for a minimum of two-months of follow-up information after fulfillment of vaccination before devoting for emergency approval.
6. Short-term safety is reasonably confident because these vaccines have been experimented in tens of thousands of volunteers under close surveillance. However, long-term outcomes are unidentified. Unknown does not necessarily indicate unsafely.
7. Long adherence of extensive numbers of vaccinated people is the only approach to notice very irregular occasions, whether it is short-term or long-term.Very rare events are those that arise in fewer than 1 in 10,000 people. Such effects need not manifest even when tens of thousands of people have been vaccinated.
8. It is important to know the technical difference between severe and serious adverse events while interpreting vaccine literature. A serious side effect is an event leading to hospitalization, significant disability,, or death. A severe side effect is a broader term that also includes non-life-threatening outcomes.
9. Two events occurring in sequence need not necessarily be connected. All human beings are subject to random happenings of serious diseases such as heart attacks, sudden deaths, infections, allergies, cancer, stroke, and another neurological disease. Also called ‘background rates’, they differ between countries due to several grounds including contrasts in monitoring systems. When such a random event occurs in a person who has also received a vaccine recently, it could get falsely attributed to the vaccine.
10. The concept of risk means different things to different people. What is considered routine by one person might be called dangerous by another.
11. The success of a vaccine in controlling a pandemic depends on how many people actually receive it. For instance, a US study has projected that if a vaccine of 80% efficacy is used, at least 75% of the population will need to be vaccinated to achieve adequate immunity levels in the community.
12. Several people have said they will not take the vaccine as soon as it gets released. Whether this fraction will increase or decrease is unknown. Public trust is a key element here. A recent survey in India showed that 59% are unwilling to take it right away.
13. Younger adults know they are at low risk of dying from the SARS-CoV-2 virus and might decide it is worth taking the (known) risk of natural infection rather than the (unknown) risk of a man-made vaccine. It is not easy to find fault with that viewpoint.
14. Human immune response against different types of viruses is variable. Though all viruses induce an immune response, not all immune responses confer immunity. For instance, in the case of viruses like measles and chickenpox, immune response following infection or vaccine provides life-long immunity from another attack. In the case of other viruses in this family, immunity from one infection lasts only for a few months to years.
15. An important question that comes up, therefore, is whether people who had been infected once by the SARS-CoV-2 virus could get it again. As is the rule with the Coronavirus family, re-infections are known to occur with the SARS-CoV-2 virus, but this fact has consistently been played down by academics. Although considered ‘rare’, their true incidence will never be known.
It is unknown at this time whether those who receive a vaccine will get reinfected, how many will get re-infected, what the severity will be, what the average duration of protection is, and how often a booster dose will be required.
16. some experts believe that a vaccine will provide greater protection than natural infection, but this is speculative at this point. There are early reports that vaccines, through their standardized dose and targeted approach, generate higher neutralizing antibody titers than natural infection.
17. Most of the mainstream vaccines are executed against the spike protein, which is effectively the landing pad of the virus. As the virus attaches to our cell surface, this landing pad works like a key that turns a lock located on the cell membrane- called the ACE-2 receptor. Vaccines including Pfizer, Moderna, Astra-Oxford, and Sputnik-V, through a range of mechanisms, essentially trick the body into generating antibodies against only this part of the virus. If the real virus attacks us in the future, these antibodies act like a piece of bubble gum or superglue that blocks the key from opening the lock.
Early results of the vaccine trials are consistent with this explanation; those who received the vaccine have had fewer symptomatic infections compared to the placebo group. However, we do not know if any of the vaccines reduced the number of asymptomatic infections yet.
18. Since vaccines are not proven yet to reduce asymptomatic infections or nasal shedding of virus in man, we do not know if vaccination will reduce the spread of the virus. This is not the same as reducing the risk of developing the symptomatic disease, which was the end-point measured in the studies reported so far.
19. Vaccination is therefore not a guarantee against infection. Asymptomatic infections could occur among vaccinated individuals. Such people may spread the disease while socializing because they feel well, and by ignoring precautionary measures because they believe they are immune.
20. How the above factor fits into the pandemic spread equation is unclear. Superspreading events could occur as a result of this new-found confidence. Socially active caregivers of the elderly might end up giving them the virus.
21. While data released by vaccine manufacturers might be accurate, it isn’t considered as dependable or comprehensive as that published in a reputed medical journal after peer review. Subgroup analysis could reveal pitfalls in interpretation that the overall percentages might have overlooked.
22. According to the data released by the manufacturers, the overall number of symptomatic infections is lower among those who received the vaccine, compared to placebo. However, the exact number of infections in vaccinated and placebo groups among the elderly is not known yet. Pfizer and Moderna trials have included a considerable number of elderly participants, results are awaited.
23. Random reports of serious side effects following vaccination can generate unreasonable anxiety amounting to panic. Such panic is comparable to people reacting to the story of a plane crash and then deciding that flying is unsafe. However, it must be remembered that unlike a medication given to cure someone who is already sick, vaccines are given to previously healthy people.
24. Fake news about vaccine adverse outcomes is perhaps the greatest threat that will affect public confidence. Fake news travels fast on social media platforms, helped along by people who readily share among their contacts without attempting verification.
25. As is the case with any product, there could be better vaccines in the pipeline. However, doing more placebo-controlled trials is almost ruled out because it is unethical to ask someone to take a placebo when an approved vaccine is already in use.
It is remarkable that vaccines have been created, tested in trials, and consent procedures started in less than a year. Effectiveness and safety are two key elements of a vaccine as explained in some detail above. The preliminary results on vaccines are inspiring , but long-term compliance is needed to acquire a more precise idea. Unknowns must be corrected with scientific proof, not by speculation. Creating public trust is important at this time. Trust is a commodity that can’t be purchased or manufactured and has significant cultural variation. A few of the elements bthat determine trust are transparency, accountability, and effective communication.
Credits; Dr Rajeev Jayadevan
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