Have Pakistanis developed short-term immunity to COVID?

ISLAMABAD: A member of the Scientific Task Force on COVID-19, Prof Dr Javed Akram has said that the sudden decrease in coronavirus cases in the country was due to a combination of factors, including a short-term immunity.

He said this while speaking to Dawn News as Pakistan's national positivity ratio showed a decline, recorded at 6.02% in the last 24 hours, with 1,716 patients in critical condition, according to the National Command and Operation Centre (NCOC) on Friday.

Dr Akram said that when a large population is exposed to a pandemic, human bodies/people try to build short-term antibodies against the disease, which is also known as sub-clinical disease or asymptomatic disease. It means that people may become infected but exhibit few or no symptoms. It's also known as Exposure Induced Immunity, and it causes disease or cases to drop suddenly in society, he explained.

Other factors behind the decline in new infections, according to the health expert, included the ban on large gatherings and the implementation of the COVID-19 protocols. 

While emphasising the need for booster shots, Dr Akram said that people should remember that the disease has been reduced but not eradicated, so they should strictly follow standard operating procedures because the virus can resurface.

'Stealth Omicron (BA.2)' has been reported in Norway and Sweden, according to Dr Akram, who is also the Vice Chancellor of the University of Health Sciences.

"We don't know how infectious and transmissible the new sub-variant is, but keep in mind that the world is a global village, and every variant has spread around the world. There is a strong possibility that new variants will emerge in the future," he was quoted as saying by the publication.

In Pakistan, however, the population seems to have developed a short-term immunity to COVID-19 as daily cases began to fall in the first week of February.

On January 27, the country reported that 8,183 people were infected, the highest number of cases in a single day since the pandemic began.

However, another 47 people are killed by a deadly virus across the country in the last 24 hours.

BA.2 form of the Omicron coronavirus

The emerging BA.2 form of the Omicron coronavirus variant does not seem to be any more severe than the original BA.1 form, an official of the World Health Organization said early February.

Vaccines also continue to provide similar protection against the different forms of Omicron, Dr Boris Pavlin of the WHO's COVID-19 Response Team told an online briefing.

The comments came as the BA.2 subvariant began to replace Omicron's more common "original" BA.1 subvariant in countries such as Denmark.

Based on data from Denmark, the first country where BA.2 overtook BA.1, there appears to be no difference in disease severity, although BA.2 has the potential to replace BA.1 globally, Pavlin added.

"Looking at other countries where BA.2 is now overtaking, we're not seeing any higher bumps in hospitalisation than expected," he said.

BA.2 is more transmissible than the more common BA.1 and more able to infect vaccinated people, according to a Danish study which analysed coronavirus infections in more than 8,500 Danish households between December and January. 

The subvariant is already becoming dominant in the Philippines, Nepal, Qatar, India and Denmark, Pavlin said.

He added: "Vaccination is profoundly protective against severe disease, including for Omicron. BA.2 is rapidly replacing BA.1. Its impact is unlikely to be substantial, although more data are needed.”

Additional reporting from Reuters