What is Omicron XBB.1.5? India gets its first case of new Covid variant that’s spreading fast in US

Fresh variants of the Covid-19 virus are raising alarms in many countries besides China. As per news reports, the Covid omicron XBB.1.5 variant is rapidly spreading in the US. According to a TOI report, India has confirmed its first Omicron's XBB.1.5 case in Gujarat in December, as per Insacog data. 

The Omicron subvariants XBB.1.5, BQ.1.1, BQ.1, BA.5 and XBB are causing almost all Covid-19 infections at present in different countries, according to data shared by the US Centers for Disease Control and Prevention. Scientists have said that of all these, the XBB.1.5 variant is highly immune evasive and appears more effective at binding to cells than related subvariants.  

As per scientists, the original BA.2 sub-variant of Omicron was combined to create XBB. According to US scientist Eric Topol, its descendant, XBB.1.5, has a tighter bind to the ACE2 receptor, which is why it has increased levels of transmissibility, the TOI reported. 

As per the report, Maharashtra state public health authorities are now concentrating on preventing the sub-variant from entering their state as it is very close to Gujarat. 

What is Omicron XBB.1.5 variant? 

The variant XBB was first identified in India in August. It quickly became dominant there and in Singapore. Since then two more of its subvariants, XBB.1 and XBB.1.5 have been found. Scientists and public health officials have been closely monitoring the XBB subvariants for many months now. As per news reports, although many public health experts are expressing concern about the rising Covid cases in China, infectious disease experts have been increasingly worried about the XBB.1.5 variant. 

As per Yunlong Richard Cao, a scientist and assistant professor at Peking University, XBB.1.5 not only evades protective antibodies as effectively as the XBB.1 variant, which was highly immune evasive, but also is better at binding to cells through a key receptor. 

As per a thread of tweets he published on Tuesday, Cao noted that even BF.7 breakthrough infection doesn't induce high neutralisation against XBB.1 and XBB.1.5. The S486P mutation only caused a slight reduction in immune evasion capability. mRNA breakthrough infection samples (n=9) here all received at least 2-dose mRNA vac. 2/vasive, but also better at binding to cells through a key receptor. 

Many experts have noted the resistance of the XBB subvariants to antibodies from vaccination and infection as “alarming” at this stage. They have highlighted that most XBB subvariants are more effective at dodging protection from the omicron boosters than the BQ subvariants, which are also highly immune evasive. 

XBB variants in India 

Talking about the XBB.1.5 cases in India, Dr Pradeep Awate, a surveillance officer in Maharashtra, has said that the state is monitoring the genetic traces left by the virus. It is conducting 100 per cent of the genetic sequencing, and 2 per cent of the overseas arrivals are also being randomly sampled.  

International arrivals are also subject to thermal screening. After that, samples that test positive are sent for genomic sequencing, the TOI report stated.  

He said: “We have more than 275 cases of XBB in Maharashtra. But XBB.1.5 is another offshoot and little is known about its transmissibility. But being an XBB descendant, it indicates that there is only a minor change in the original version of the sub-variant. Still, we are taking necessary precautions to prevent its entry/spread in the state," Awate was reported saying by TOI. 

Cases in the US 

As per the data results published by the Centers for Disease Control and Prevention on Friday, XBB.1.5 now represents about 41 per cent of new cases in the US, especially in New York. The cases have reportedly nearly doubled over the past week, when its prevalence was 21.7 per cent.  

Earlier in November, Dr Anthony Fauci, White House chief medical advisor, noted that the XBB subvariants reduce the protection the boosters provide against infection multifold. 

In a briefing last month, he said that he was encouraged by the case study of Singapore, which had a major surge of infections from XBB variants but did not see hospitalisations rise at the same rate.  

Scientists have noted that XBB.1.5 spread could surge in the coming days as the holiday travel would be on due to the yearend.