“I am really frightened; it is not a wave, it is a tsunami this time,” said Dr Rajesh Gupta, additional director, Pulmonology and Critical Care, at Fortis Hospital, Noida, as he rushed towards the COVID ward which he heads.
A month back, Dr Gupta, a recovered COVID patient himself, had stopped wearing the PPE kit. Not because of any discomfort it caused, but because the numbers of COVID cases had fallen to an all-time low by the first week of February, with not a single COVID patient in his ward. Six weeks later, the hospital’s ICU is packed to capacity and he is back to wearing the PPE kit.
The virus which ravaged the country last year has returned with a vengeance. As on April 15, the country reported 2,16,902 cases, and 1184 deaths in 24 hours, which took the total number of active cases in the country to 15.69 lakhs. With the current daily positivity rate, India has surpassed the US and Brazil in the total number of cases and is now reporting more cases than any other country. In Maharashtra, which accounts for about half this number, the health care system seems on the verge of collapse. As seems to be happening in other states too. Delhi recorded 16,699 cases on April 15, with a positivity rate of 20.22%.
So, how did the daily case count go up from 8000 to over 2 lakhs? Complacency of people who ignored COVID-appropriate precautions is one obvious reason. But the more frightening reason, according to experts, is that they are seeing a more virulent mutant of the virus. The highly transmissible variant B.1.1.7, which caused the second surge in the UK , has been detected in some states. Then there is the double mutant variant, classified as B.1.617, which according to the National Institute of Virology (NIV) was found in 220 of 361 genome-sequenced samples collected between January and March this year.
This variant carries two mutations, E484Q and L452R. The L452R mutation increases the binding power of the virus’s spike proteins on human cells. It makes it more transmissible. Experts also feel that this mutation helps the virus to replicate faster inside the human body. Both E484Q and L452R mutations not only make the virus more infectious, but also help it evade immunity. Experts recommend ramping up of its gene-sequencing, which will help understand which viral mutant is causing the surge and how.
“This year we are better prepared to tackle the virus medically as we know what to do and when,” says Dr Gupta. “But only if the number of patients is manageable. We need to work on a war footing to stop COVID-19 from spreading uncontrollably. Thankfully, the clinical manifestation has not changed much. Most patients are exhibiting the same old symptoms like cough, congestion, fever, body ache, etc.”
What worries Dr Gupta and other experts is the fact that when a highly transmissible virus spreads, its chances of undergoing severe mutations increases. “Especially when the mutation displays more aggressive properties,” says noted virologist Dr Raman Gangakhedkar, former head, epidemiology, ICMR. “For example, the UK variant B. 1.1.7 is 50% more transmissible. So if a person infected with an earlier strain was infecting two others, patients infected with this new strain will infect three. The only saving grace so far is that it does not seem to be more lethal. But when the number of affected people goes up, the proportion of severely affected also rises.”
Dr Samiran Panda, head, epidemiology and communicable diseases, ICMR says, according to the third national serosurvey in December-January “only about 25% of Indians had developed immunity against the virus, which means that 75% of the population remains susceptible to infection”.
With new mutations causing a rapid increase in the net positivity rates among those tested, hospitals are witnessing a sudden increase in COVID positive patients needing hospitalisation, which in turn is causing a shortage of oxygen supply, ventilators, and anti-viral drugs such as Remidesivir, an injectable anti-viral drug that is used in the early stages of the illness to reduce viral replication inside the patient’s body. The government has now prohibited the export of Remdesivir and active pharmaceutical ingredients (APIs) required in its production.
Know your vaccine
Only an aggressive and rapid increase in the number of people getting vaccinated will help in reducing the severity of the disease, say experts. India started the vaccination drive on January 16th, and has added more categories of people who are eligible to get vaccinated, taking that number to 40 crore, a third of India’s population. But India has vaccinated only a little over 10 crore people at the time of writing. With the current daily average of 33 lakh doses administered, the country is unlikely to cover the whole of this target population by August, as originally envisaged.
“We have adequate doses for the target population,” says Dr N K Arora, advisor, national AEFI committee. “People must come forward to take the vaccine. India has 40,000 vaccine centres with a capacity to vaccinate 80 lakh people every day. Currently, we are not vaccinating even half our capacity.”
But vaccine hesitancy remains, with people questioning the efficacy of vaccine as there are cases of people contracting COVID even after vaccination.
Scientists and infectious disease experts are trying to find answers to what they call ‘the breakthrough infections’ – how and why the virus overcomes the vaccine-induced immune response. The human immune system is complex, with different individuals developing different degrees of immunity post-vaccination. Some people may show a weaker immune response to the vaccine than others, say doctors. Vaccine efficacy is another factor.
“Both the vaccines available in India have efficacy of more than 70-80%,” says Dr Shekhar Mande, director general, CSIR, New Delhi. “People being infected post-inoculation are probably 20-30% who don’t get protection through a vaccine. Besides, we need to study the intensity of the disease in those vaccinated. If the intensity of the infection remains lower, it reduces the need for hospitalisation and mortality significantly.”
Dr Panda of ICMR adds another twist to the vaccine tale. ““The vaccines available in India — both Covishield and Covaxin — are not infection-preventing vaccines, these are disease-modifier vaccines that means they don’t prevent against the infection, they protect against the severe disease,” says Panda. “That’s why it is important that we strictly follow the time-tested strategy for preventing the infection — COVID-appropriate behaviour”.
Also getting more strident are demands from various quarters to open up vaccination for all above 18. However, experts feel otherwise.
“To vaccinate all above 18, around 900 million people, India would require 2 billion doses and we don’t have these many doses with us,” said Dr Arora. “India is at a critical juncture right now, with the number of cases increasing sharply. But whether vaccination should be open for all should be a scientific and strategic decision. If you look at the COVID data, about 90% of the COVID-related deaths are in people above 45. So our priority is to save those who are vulnerable to developing severe conditions. This way we can reduce the hospitalization.”
The emergency use approval of Russia’s Sputnik V can help improve the national coverage at this stage. Developed by Gameleya National Research Institute of Epidemiology and Microbiology, Moscow, Sputnik V vaccine uses two different adenoviruses, which are not known to cause infection among humans. Some variants of adenovirus cause common cold. But the adenovirus in the vaccine delivers a piece of genetic code to human cells, allowing them to make spike protein, the receptor-binding protein on the surface of the coronavirus. This stimulates the body to generate antibodies against the coronavirus.
So, how is it different from AstraZeneca’s Covishield, also an adenovirus vaccine? “Covishield uses adenovirus which causes infection in chimpanzees and it uses the same adenovirus for both doses,” said Dr Gangakhedkar. “Whereas, Sputnik V uses two different adenovirus vectors for the two doses, Adenovirus26 (Ad 26) and Adenovirus 5(Ad5)”.
Sputnik V vaccine has also to be stored at 2-8°C, the temperature at which we currently store Covishield and Covaxin. Sputnik V has a protective efficacy of about 91% and has been found to be safe. Currently, the vaccine has been used in around 60 countries. India is set to receive its first batch of Sputnik V by April last week. Dr Reddy’s Laboratories, Hyderabad, will be one of the major producers of the vaccine in India. Five more pharma companies including are aiming to produce about 850 million doses of Sputnik V a year.
While Sputnik V is likely to give a major boost to the country’s inoculation drive, in the final analysis, COVID-appropriate behaviour continues to be the most potent tool to fight the current virus surge.