Karachi's Covid-19 positivity rate on Monday crossed 22 per cent, the highest in the country, amid concerns of a surge in cases.

According to data shared by the National Institute of Health (NIH), the positivity rate in the metropolitan city was recorded as 22.65pc over the last 24 hours. Muzaffarabad came in second with a positivity rate of 6.25pc, followed by Nowshera with 5pc.

Interestingly, the positivity rate in several cities including Quetta, Diamer, Gilgit, Skardu, Bannu, Swabi, Swat, Bahawalpur, Gujranwala, Gujrat, Jhelum and Multan was recorded as 0pc.

The NIH also shared that 13,412 Covid-19 samples were tested during the last 24 hours, out of which 382 came back positive, down from 406 a day earlier. The national positivity rate was recorded as 2.85pc.

Two more deaths were also recorded during this period while 87 patients were in critical condition. The total number of cases is 1,534,270 while the death toll is 30,390.

Meanwhile, in light of the apparent increase in Covid-19 cases, the NIH said the National Command and Operation Centre (NCOC) — which was primarily responsible for Pakistan's coronavirus response until earlier this year — had recommended making face masks mandatory on all domestic flights, railways and public transport.

"So all citizens are requested to wear a face mask during travel," the NIH said.

The NIH's advice comes a day after the Civil Aviation Authority (CAA) made wearing face masks mandatory on domestic flights with immediate effects.

The CAA directed all quarters concerned to ensure compliance with the new order,but added that the other Covid-19 guidelines on domestic air travel remained unchanged.

People urged to get booster amid surge

Dr Samreen Ashraf Qureshi, Sindh's focal person for Covid-19, told Dawn that the general public was not taking the warnings over coronavirus seriously.

She said the turnover for booster shots was low despite high infectivity of the new variants and rapid increase in Covid-19 cases, particularly in Karachi and Hyderabad, All designated vaccination centres, she said, were active in the province where people could get free-of-cost booster shots.

“Major Covid-19 vaccination facilities in Karachi include the Jinnah Postgraduate Medical Centre, Dr Ruth Pfau Civil Hospital Karachi, Dow University Hospital, Ojha campus, Children Hospital in North Nazimabad and Thaddo Nalo centre in Malir,” she said.

A booster shot could be received after five months, she added.

“We are experiencing the start of the sixth coronavirus wave driven by BA.4 and BA.5 sub-variants. They have several changes in their genetic make-up, which means that they will continue to spread fast and the positivity rate may reach 50pc,” feared Dr Saeed Khan, a professor of molecular pathology heading the Sindh Public Health Lab at Dow University of Health Sciences.

This pattern, he pointed out, was very much similar to that being seen in other countries, including the US. “Right now, we don’t have complete protection against the new mutated viruses, which escape immune response. Cases are likely to increase till herd immunity is achieved.”

Disease severity, he pointed out, would likely be less in most cases, urging people to get a booster jab.

“The sick and people with comorbid health conditions will still be at risk. Hence, it is wise that people get a booster jab or second booster shot, if five months have passed to their first dose,” he said.