As Coronavirus cases surge in Delhi — the case positivity rate has risen to 17.83 per cent and eight deaths have notched up the highest mortality in 180 days — there are anxieties. A study at the Lok Nayak Jai Prakash Narayan Hospital has also found Omicron’s new sub-variant — BA.2.75 — which is fuelling the latest spike, has a higher transmissibility.
Just a day ago, a report in Nature has said how the BA.2.75 sub-variant of Omicron has been nicknamed ‘Centaurus’ by some on social media. The report further says, “A few scientists are sounding the alarm, whereas others say it’s too early to tell whether the variant will spread widely. In India, it doesn’t yet seem to be driving up hospitalisation or death rates. BA.2.75 has been detected in more than 20 countries worldwide, and researchers are waiting to learn whether it will substantially elevate case numbers after a wave of infections with BA.5. A slew of studies suggests that the two variants have roughly similar capacities to dodge immunity conferred by infection and vaccination. This suggests that ‘Centaurus’ might not push cases much higher outside India — at least not while population immunity is high and before the variant picks up many extra mutations.”
Quoting Tom Wenseleers, an evolutionary biologist at the Catholic University of Leuven in Belgium, Nature reports that BA.2.75 has “quite a sizeable” transmission advantage over BA.5 in India. “This would definitely cause an infection wave,” he says. So what are the markers that we should be watching out for?
LOOK OUT FOR THESE SYMPTOMS: HIGH FEVER AND VERY SORE THROAT
“Clinically this surge is mild, possibly caused by a new sub-variant of Omicron. This means there are no life-threatening symptoms, severity of the disease or dip in oxygen levels that warrant our anxiety. Please understand that deaths are being hastened by existing co-morbidities, not COVID 19 itself. But the symptomatic manifestation is much more than the first wave of Omicron. This time, the fever is on the much higher side, patients are suffering chills and getting bad headaches, backaches and a sore throat. Sometimes I have had patients finding it difficult to swallow as their throat is hurting badly,” says Dr Nikhil Modi, Consultant, Respiratory Medicine, Indraprastha Apollo Hospital, New Delhi. The high fever lasts for about three odd days, starts settling by the fourth day and then there is gradual remission between the fifth and seventh days. “What’s new is chest congestion or bronchitis brought on by a supplementary bacterial infection that’s setting in once the fever starts subsiding,” adds Dr Modi.
OVERLAP OF SYMPTOMS WITH OTHER INFECTIONS, SWINE FLU ALSO ON THE RISE
This is also the time when all of us are more prone to getting affected by the seasonal flu, swine flu (H1N1) dengue and malaria. “In fact, isolating the reason is taking time. It is only after a patient tests negative for COVID-19 that we are testing them for other diseases. That’s how we have found that swine flu cases are rising too, though we have not been talking about it the last two years,” says Dr Modi.
IS THE LATEST OMICRON SUB-VARIANT MORE TRANSMISSIBLE?
“It is as transmissible as previous sub-variants of Omicron,” says Dr Modi, adding that if “you are around an infected person, you have a high chance of contracting it.” This means that even if one person in a family tests positive and others show the same symptoms, chances are that they have been infected. Many reports have already said that the newer sub-variant is more transmissible by 20 to 30 per cent . Also patients with worsening symptoms requiring hospital attention need to get tested for multiple infections of COVID-19 co-existing with dengue.
IS THE NEW SUB-VARIANT DRIVING BREAKTHROUGH INFECTIONS AND RE-INFECTIONS?
“I would say I am seeing more patients who have been infected by other Omicron variants. Those who had Delta are also getting the new variant as are those who have been triple-vaccinated. Let me clarify here that vaccines are still preventing the severity of the infection. Immunity, we must remember, is strain-specific. And for a virus that mutates and changes its genetic make-up, the vaccine may not have a targetted response and not work fully against the new virus but gives you an umbrella protective shield. Besides, for a population that has mostly got some variant of the COVID-19 and been vaccinated, the hybrid immunity seems to be working better,” says Dr Modi.
Latest research has shown that both BA.5 and BA.2.75 have a similar ability to evade antibodies triggered by vaccination and previous infection. In fact, a specific research by Dr Yunlong Richard Cao, an immunologist at Peking University in Beijing, has found that several people who had had Delta infections produced antibodies after vaccination that were more potent against BA.5 than against BA.2.75.
WILL DELHI CONTINUE TO SEE SURGES AND WAVES?
“What we have gathered from the surges and waves in Delhi is that sequentially the numbers and the rate of hospitalisation go down. With each mutation, the virus weakens further and once Covid becomes endemic in your area, expect repeated bouts just like seasonal flu,” says Dr Modi. “There is no need to panic. You just need to build your immunity with exercise and a healthy, balanced diet. Just stick to good lifestyle markers ,” he adds.
WHAT ABOUT MASK AND SOCIAL DISTANCING MANDATES?
“The problem is we depend on the Government to issue an order for compliance. But let me be very clear, that given COVID is a reality, we have to imbibe behavioural discipline in our mind. Wearing masks, hand-hygiene, social gatherings in known and safe groups should be a voluntary drill,” says Dr Modi. “But look around you and nobody is wearing the mask. Also there is a false sense of invincibility that two rounds of vaccination and one bout of infection have been good enough to protect oneself against future variants. People are callous about taking the precaution dose,” he adds.
Official data from the city health department shows that till August 2, the total number of booster doses administered was 22,19,059. And the number is hardly going up despite worries about the new surge.