Rania Bibi had spent four years administering polio drops in the backstreets of Lahore's Ravi Town neighbourhood before Covid-19 paused her life-saving work.

Pakistan's vast effort to stamp out the crippling childhood disease was put on hold in March amid fears door-to-door polio vaccination would spread the new coronavirus.

The break to her duties could not have come at a more difficult time. While the world in August celebrated the eradication of wild poliovirus from Africa, the news from its final two haunts of Pakistan and Afghanistan has been grimmer.

Cases rose sharply in 2019 and international monitors gave the programme a severe review for poor performance. Then just as efforts were being overhauled and redoubled, Covid-19 stepped in and shut them down.

It was while she was on this enforced break that Ms Bibi received the awful news that a toddler on her vaccination patch had caught polio and died.

“I cried when I heard he had died,” she told The National.

The death of 26-month-old Muhammad Ali in July was all the more disheartening because it was not the first in Ravi Town in 2020.

Lahore, the capital of Pakistan's Punjab province, had until recently appeared clear of polio after enormous efforts to vaccinate the young inhabitants. After recording a case in 2011, the city remained disease-free.

By 2018, the whole of Pakistan seemed on the verge of eradicating the childhood scourge. Health officials recorded only 12 cases in the whole of that year.

Yet on the cusp of a historic public health victory, the trend instead reversed. Last year saw 147 cases nationwide, including five in Lahore, and sewage samples show the virus is widespread.

An independent board of eminent public health doctors which monitors the global eradication campaign recently criticised the “jaw-dropping slump of performance”.

The board led by Sir Liam Donaldson, formerly England's chief medical officer, warned that unless Pakistan managed to shake up and turn around its programme within six months “the wheels will come off the Pakistan bus”.

With the pandemic, fortunately, having subsided in Pakistan, at least for now, the country's army of health workers resumed nationwide door-to-door campaigns late last month.

Dr Rana Muhammad Safdar, national co-ordinator for the campaign, admits there were “challenges” in 2019. Complacency had set in and political rifts were undermining efforts. The poorest resent the time and investment given to a polio campaign when the government will not provide even clean water or electricity. Most worrying has been a stubborn level of suspicion and conspiracy theory directed at the drops. Long-standing accusations that the campaign is a western plot to sterilise Muslims, or that the drops are otherwise harmful, have been fed by extremist groups and turbocharged by social media. The propaganda led to near hysteria in April 2019, when false rumours spread around the north-eastern city of Peshawar that schoolboys had fallen ill. In a single day, parents rushed 25,000 children to hospital and a state of emergency was declared.

Dr Safdar says lessons were learnt. The campaign has been given across-the-board political backing, he says, and education and outreach efforts have been redoubled. A revitalised campaign was launched late in 2019, only then to run headlong into the pandemic. Epidemiologists worry the hiatus will lead to a further increase in cases.

“Everyone was so depressed when we were regaining some momentum and Covid hit,” Dr Safdar says.

Capt Usman Younis, health secretary for Punjab, said it had been “disheartening” to see polio creep back into Lahore.

“We are very hopeful in about four months we will have a very, very different Punjab. Obviously, Covid has done some amount of damage because we did not do enough campaigns during this time,” he said.

The country's brush with coronavirus has made parents cautious, he said. When workers like Ms Bibi returned to work in late September, they wore masks and carried hand sanitiser on top of their usual equipment.

Nationwide, 260,000 vaccinators sought to vaccinate 40 million children and Ms Bibi was among 4,000 door-to-door teams working in Lahore alone, with another 1,000 teams posted in bazaars and bus stations to vaccinate passing children.

The death of little Muhammad Ali had made her more committed to finishing the job, she said.

“I'm motivated to do more.”