India could be gripped by a third coronavirus surge within weeks as it eases lockdown restrictions on businesses and life, medical experts told The National.
Daily infection rates have slowed from a peak of more than 400,000 in early May to nearly 60,000 on Sunday.
But the public precautions and preventive measures against Covid-19 have also eased.
Across the country's largest cities, huge crowds browsed in markets and shopping malls for the first time in weeks after restrictions were lifted.
The second wave, which hit in March, led to 20 million cases being reported and a death toll of nearly 250,000.
But as the authorities began to reopen public life to revive the economy, experts said a third wave was becoming “inevitable” as crowds yet again lowered their guard against infection.
“Again crowds are building up, people are gathering,” said Dr Randeep Guleria, chairman of the country's main hospital, All India Institute of Medical Sciences.
"It will take some time for the number of cases to start rising at the national level.
“A third wave is inevitable and it could hit the country within the next six to eight weeks, maybe a little longer."
India is slowly emerging from the devastating effects of the second wave, which began months after infections ebbed after the first peak late in September.
By February it hit a low of 8,000 cases a day, sparking a sense of triumph in the public and the government that declared the country had defeated the pandemic, before a local variant began to spread rapidly.
Experts blamed large political and religious gatherings and opening of public life for the wave, during which India's healthcare system nearly crumbled and millions struggled to get oxygen, medicine and hospital beds.
One of the worst-hit cities, New Delhi, faced death and despair throughout April and May as patients choked outside hospitals because of a lack of oxygen, while crematoriums ran out of space.
But in recent weeks, scenes across the capital's markets have not only defied the grim memories but also blatantly ignored coronavirus prevention.
Markets were packed with crowds, with many people not wearing masks or leaving them dangling after New Delhi reopened in early June after a six-week strict lockdown in which infections increased to 28,000 a day in April.
The city reported 124 new cases on Sunday, prompting authorities to allow restaurants and bars to open with 50 per cent seating capacity.
They further relaxed rules for public parks, gardens, shopping malls, golf clubs and outdoor yoga sessions, which opened last week.
On Friday, a Delhi court said there could be a third wave of Covid-19 if people continued to breach safety measures.
“Such breach of Covid protocol will only hasten a third wave, which can’t be permitted at all," it said.
The scenes were no different in cities across neighbouring Uttar Pradesh state, where crowds defied coronavirus rules.
The state government increased working hours for markets and allowed shopping malls and religious institutions to function at 50 per cent capacity.
In Haryana state, gyms, sports complexes and stadiums have been allowed to reopen.
The southern Telangana state has lifted all curbs on public life after what the government called a "drastic drop" in the number of positive cases.
But with the easing of restrictions, the slow pace of vaccination and concerns over a new mutation of the Delta variant, called Delta-plus, experts say that masks and social distancing are the only ways for people in India to protect themselves against a third wave.
"People must behave sensibly and public administration must be vigilant in preventing super spreader events," Dr K Srinath Reddy, president of the charity Public Health Foundation of India, told The National.
"Otherwise, the virus will hit us hard again."
Dr Jayaprakash Muliyil, India’s leading epidemiologist, said although cases may be dropping, the coronavirus is still present.
“This is an unfortunate infection gifted to the world," Dr Muliyil said. "Every activity, education, industry has to go on but people should follow the basic rules of masking and avoid being in crowds.
"It might feel like the curve is flattening but the virus is not completely gone.
India has administered about 270 million vaccine doses, covering just over 3 per cent of its 1.3 billion people with two doses and nearly 17 per cent with one.
Experts say the country will have to aggressively vaccinate all of its citizens before a new surge hits the country.
“The vaccination has to sustain and increase to make considerable gains over the next few months," said Giridhar Babu, an epidemiologist with the PHFI.
"India will have another wave based on some of the mathematical predictions in October.
"Before that, aggressive containment and vaccination is required wherever outbreaks are reported."