The Aga Khan University Hospital (AKUH) confirmed on Wednesday the detection of six coronavirus cases belonging to the highly-contagious Omicron subvariant category XBB in Karachi.

“We have detected six cases, however, others have been found around the country,” AKUH Infectious Diseases Section Head Dr Faisal Mehmood told Dawn.com. “These have started since November.”

According to the World Health Organisation (WHO), the XBB is a highly contagious subvariant of Covid-19’s Omicron strain. As per early evidence, the XBB variant had a higher reinfection risk, as compared to other circulating Omicron sublineages.

A statement by the US Centres for Disease Control (CDC) on Dec 31, around 40pc of confirmed US Covid-19 cases were caused by the XBB.1.5 strain, a relative strain of the XBB variant.

Dr Mehmood said the XBB variant can spread rapidly, especially in people who do not have pre-existing immunity from vaccination or previous infections.

“The symptoms are similar to the other Covid variants,” he added, encouraging vaccinations for people who have not received the booster shot or have low immunity.

The infectious diseases expert said adequate amounts of testing were the most important thing to counter the new variant’s spread.

He advised the public to get a booster shot if they haven’t already.

“If you have any symptoms, you should get tested or at least wear a mask and avoid other people to prevent the spread of the virus,” he said. “If your immunity is low because of age or other medical conditions, avoid crowded areas, adopt masks, and ensure your vaccinations are up to date.”

Commenting on whether the vaccines administered in the country would provide protection against the XBB variant, the AKUH expert said: “The new variants are able to still infect people who have had the vaccination, however, the symptoms tend to be mild.”

When asked if the presence of the variant could prompt a new lockdown, Dr Mehmood said it was “highly unlikely” and “will not be required”.

“We do not expect to see a surge the way that China is which is in a different situation given that most of the population is not immune and vaccination which was not as effective,” he said. “China recently reduced their lockdown which has left a large number of the population vulnerable to the virus.”

Separately, spokesperson for the Sindh Health Department, Mehar Khursheed, told Dawn.com that cases of the XBB variant were not a cause for concern since the strain was the predominant one across the world.

“All of Sindh’s population is vaccinated with double doses, boosters are being administered as well,” she said, adding that children were also being vaccinated in populous areas.

No cases of BF.7 variant so far

Dr Mehmood said the Covid variant spreading rapidly in China was called “BF.7”.

Upon being asked if any cases of the BF.7 variant were found in the country, Dr. Mehmood said not yet, but he would not be surprised if it was already present.

National Command and Operation Center (NCOC) and the National Institute of Health (NIH) also refuted news of the sub-variant BF.7.

“Currently, XBB Omicron sub-variant is already the dominant variant for the last three months,” NIH tweeted. “NCOC is closely monitoring the situation.”

The BF.7, short for BA.5.2.1.7, is a sub-lineage of the Omicron variant BA.5.

The two are being tracked as variants of concern by authorities in China and the US.

China’s axing of its stringent virus curbs last month unleashed Covid on a 1.4 billion population that has little natural immunity having been shielded from the virus since it emerged in Wuhan city three years ago.

A senior doctor at one of Shanghai’s top hospitals said 70 per cent of the megacity’s population may have been infected with Covid-19 during China’s huge surge in cases.