Pfizer and-BioNTech vaccine has an accuracy of 94 per cent, Moderna's vaccine 94.5 per cent, Oxford's vaccine 90 per cent, and India's recovery rate (without vaccine) is 93.6 per cent. Do we seriously need a vaccine?"
Even if you are moderately active on social media, chances are high that you would have received this innuendo, or its little modified version, in the past few days. This message is doing the rounds against the backdrop of multiple reports of pharmaceutical companies applying for emergency use authorisation for their Covid-19 vaccines.
India too has received a couple of authorisation applications -- from Pfizer and the Serum Institute of India, which is testing and manufacturing the Oxford-AstraZeneca vaccine in India under the brand name of Covishield.
The underlying impression of the viral message is that Indians don't need a vaccine for two reasons -- the Covid-19 pandemic is a milder illness in India reflected in a higher recovery rate, and that the natural immunity response from contracting the novel coronavirus infection is better. This may be an erroneous conclusion to arrive at.
UNKNOWN VERSUS KNOWN
Giving too much importance to the recovery rate could be misleading. As a matter of rule, recovery rates in a pandemic increase with time. Any recovery rate is simple arithmetic coming out from the total number of infections minus those dying of the disease. Survivors are recoveries. A deadly pandemic may have a fatality rate of five per cent on the global scale. This means the rest 95 per cent would form the recovery rate at the end of the pandemic. Covid-19 has a lesser fatality rate in India. So, a recovery rate is bound to be higher on the index.
Immunity response in the body comes through two means -- natural illness by contracting the virus or induced illness, which is milder and done through vaccination. The danger with natural Covid-19 illness is that the human body's response to the novel coronavirus infection is not understood fully. It is not known to date why some people with similar health parameters develop serious illness and die, while others survive with milder illness or staying asymptomatic throughout infection.
A vaccine is tested, data is examined and safety standards are known. Knowing the enemy is half the battle won, they say in war tactics. Currently, the Covid-19 pandemic is a war that humans are fighting against a very agile virus. A vaccine induces a known immunity response to the illness. A vaccine is approved only after it is found scientifically safe.
Choosing the natural route to develop immunity against Covid-19 over a vaccine could be leading an army in the dark without the knowledge of the terrain and weapons of the opponent.
CONTROL OVER VIRAL LOAD
Covid-19 is about one-year-old and has been a top priority for scientists across the world. What is established in one research is often found unsustainable in other works. But what is fully known is that the severity of the illness in Covid-19 has a strong link with the viral load in the body. This is one pattern that is common in Covid-19 with other viral infections.
The inoculation of a vaccine ensures that the viral load is contained in the person receiving the shot. Its dose is fixed and scientifically tested backed by a body of experiments and trials. The chances of high viral load are negligible in case of vaccination, while it is not controlled if the same person contracts the novel coronavirus, SARS-CoV-2, naturally.
A vaccine prepares the body for a bigger fight in case a natural virus enters the body. In the other case situation, the body is taken by surprise and the response could be dull allowing the virus to wreak havoc inside the body leading to a situation that is often described as cytokine storm or multi-system inflammation. Both have a fatal association with human life.
LENGTH OF IMMUNITY
The scientific data gathered from almost all leading Covid-19 vaccine candidates suggests that the acquired immunity could be mid-to-long-term. That is, a vaccine may offer protection against Covid-19 for up to a few years. The T-cells, often described as the immunity system's long-term memory, have been found activated in vaccine trials.
On the other hand, the immunity drawn from natural infection could be short-lived and, in some cases, may bring a severe illness on the next contraction of Covid-19. Though this occurrence is minuscule, several individuals have been found to have contracted Covid-19 a second time.
In one particular case, a 101-year-old Italian woman, Maria Orsingher, has fallen to the novel coronavirus three times -- February, September, and November this year. Fortunately, she never developed serious complications. She had previously survived the Spanish Flu pandemic of 1918-20 as an infant.
The confidence of being "known" is the advantage with a Covid-19 vaccine over Covid-19. Based on what scientists have written about the pandemic-causing Covid-19 is a dangerous alternative to a vaccine for attaining immunity against the novel coronavirus. Covid-19 survivors can at best wait for some time before taking a vaccine. They are anyway not on the priority list of the governments anywhere in the world.