WhatsApp Message On XBB Variant Fake, Health Ministry Says. Know Facts About The Omicron Subvariant

The new Omicron subvariant XBB does not appear to have immune escape with BA.5, which means that individuals who were previously infected with BA.5 will maintain their immunity against XBB.

Covid-19 in India: Amid media coverage of the rising cases of Covid-19 in China, several fake messages about SARS-CoV-2 variants are being circulated on WhatsApp in India. A message which is being widely circulated in WhatsApp groups in the country is that the XBB strain, an Omicron subvariant, is deadly. The Union Health Ministry has said that the message about different facts of the XBB variant being circulated on WhatsApp is "fake" and "misleading". 

Some of the fake messages being shared include the fact XBB is "different, deadly and not easy to detect correctly". 

Also, the message claims that XBB is five times more virulent than the Delta variant and a higher mortality rate than it. However, this information is fake, the Health Ministry has claimed. 

The XBB variant was first discovered in August. In November, fake messages about XBB were being circulated by social media users in Singapore. They were copy-pasting a message which said XBB is "toxic" and has a higher mortality rate than Delta. There is no evidence to support this claim, a Reuters report said, citing Singapore's Ministry of Health. 

Facts about XBB

According to the World Health Organization (WHO), current data does not suggest XBB is more deadly than Omicron, which itself is less lethal than Delta. 

In a statement dated October 27, 2022, the WHO said the body's Technical Advisory Group on SARS-CoV-2 Virus Evolution (TAG-VE) recently discussed the potential risk of some Omicron variants, specifically XBB and its sublineages, and BQ.1 and its sublineages. 

XBB*, the name for the sublineages of XBB, is a recombinant of BA.2.10.1 and BA.2.75 sublineages. The global prevalence of XBB* is 1.3 per cent. The variant has been detected in 35 countries.

XBB associated with higher re-infection risk

While there has been a broad increase in the prevalence of XBB* in regional genomic surveillance, it has not yet been consistently associated with an increase in new infections. 

However, the WHO said, early evidence points at a higher re-infection risk associated with XBB, as compared with other circulating Omicron lineages. 

Most cases of re-infection were reported in people who were infected for the first time in the pre-Omicron period. Currently, there is no data suggesting escape from immune responses induced by Omicron lineages other than XBB*. 

The regional immune landscape will determine whether the increased immune escape of XBB* is sufficient to drive new infection waves, according to the WHO. The regional immune landscape is affected by the size and timing of previous Omicron waves, and the Covid-19 vaccination coverage. 

According to TAG-VE, the overall phenotype of XBB* and BQ.1*, the name for the sublineages of BQ.1, do not diverge significantly from each other, or from other Omicron sublineages with additional mutations which help them escape immune responses. Despite the fact that XBB* and BQ.1* have not been designated as new variants of concern, the WHO will continue to monitor the situation closely, and has requested countries to remain vigilant, and monitor and report sequences of the different Omicron lineages.

XBB does not cause re-infection in people initially infected with BA.5 variant

According to the University of Washington's Institute for Health Metrics and Evaluation (IHME), the new Omicron subvariant XBB does not appear to have immune escape with BA.5, which means that individuals who were previously infected with BA.5 will maintain their immunity against XBB.

Moreover, new analyses have shown that all subvariants of Omicron appear to be less severe than previous variants. 

The IHME has said that the XBB variant was responsible for the surge in hospitalisations in Singapore in October 2022. Analyses have shown that XBB is more transmissible than other subvariants, but in people infected with BA.5, XBB cannot cause re-infection. 

People who had been infected with BA.5 in the last three months had almost no incidence of XBB. However, people who were not infected with BA.5 could be at risk of infection with XBB.

Most importantly, XBB does not seem to be more severe than other variants, outside Singapore, according to the IHME. So far, all the sublineages of Omicron have remained more than 10-fold less severe compared to variants which resulted in the previous waves of the Covid-19 pandemic, the IHME has said.