KARACHI: The United Kingdom, South Africa and Brazil variants of the coronavirus might be responsible for the current severe third wave of Covid-19 in Pakistan, says a recent study.

The study, which analysed 3,501 positive samples, found that these variants were responsible for causing 54 per cent of new Covid-19 infections reported from December 2020 to February 2021 in Karachi.

According to the study, the positivity ratio in the months of September to November 2020 was 1.538pc, which jumped to 7.6pc in December 2020 to February 2021.

This dramatic rise in cases, the study shows, clearly indicates importation of cases (to Pakistan) from the countries where these viral strains were spreading before and during November 2020.

“This is the most worrisome finding of the study. It means that our Covid-19-specific monitoring and screening system at the airports is highly flawed. In fact, it seems that no monitoring is being carried out at all to detect Covid-19 patients,” said Dr Rafiq Khanani, a senior pathologist and president of the Infection Control Society of Pakistan.

‘Our fight against the coronavirus will never end if we continue to import its new variants’

Dr Khanani conducted the study with colleagues Dr Muhammad Hanif and Dr Adnan Dinar, both molecular biologists. The study has been accepted for publication in an international journal.

“Unmonitored international flights and no quarantine on arrival in Pakistan from any country seemed to have led to a rapid introduction of the variants in Pakistan,” Dr Khanani explained, adding that the spread of the pandemic globally provided an opportunity to variable strain types to thrive.

The analysis found the UK variant in 944 samples and Brazil and South Africa variants (together) in 934 samples. There were 1,623 cases of old viral infection.

Limited vaccine efficacy

He also raised concern over the situation in Punjab and Khyber Pakhtunkhwa, badly hit by the third wave of the coronavirus, and said the situation was likely to be more serious in those parts of the country (in terms of having more variant types) in coming days.

“This would have a direct impact on the vaccine’s efficacy, particularly in the case of the South Africa variant. Vaccines haven’t been found very effective against this specific variant. Second, our fight against the coronavirus will never end if we continue to import its new variants,” he said, calling for stringent monitoring at airports and ensuring compliance with isolation and quarantine protocols in case of a positive case.

About Brazil, South Africa and UK variants, Dr Khanani said they were the cause of concern globally because of their ability to transmit rapidly, causing a more severe disease, involving younger age groups and relatively infecting more females, and they could also be responsible for escape from immune responses.

“Our study also showed that these variants affect women and younger age groups more, if their pattern is compared to the previous data of coronavirus outbreak,” he said, adding that the team only analysed lab samples and could not comment on disease severity since it had no interaction with patients.

Meanwhile, experts at Karachi University’s National Centre for Virology have also detected the South Africa variant with the UK variant in the samples tested at the facility.

“Around 50 per cent of the positive cases tested at the facility involved the UK variant while 25 per cent were the South Africa variant. There is a need for genomic surveillance of SARS-CoV-2 to timely identify and contain the rapidly emerging new strains of the virus,” said Prof Mohammad Iqbal Choudhary, director of the International Centre for Chemical and Biological Sciences at the KU.

Published in Dawn, April 16th, 2021