The Omicron sub-variant BA.2, also known as the "stealth" variant, is starting to overtake BA.1, and has now been detected in 57 countries, according to the World Health Organization. The WHO shared its weekly epidemiological report on the COVID-19 pandemic giving an update on the spread of the CPVID-19 Omicron variant and its sub-lineages. Among the many details of the report is how the virus has infected 22 million people globally in the week between January 24 and January 31 and killed 59,000 people. Since Omicron was designated a Variant of Concern (VOC) in November 2021, several lineages have been identified. The ones that are most under scrutiny are BA.1, BA.1.1, BA.2, and BA.3. BA. 2 has seen a large uptick in some countries and now accounts for more than half of all sequenced Omicron variants, the UN agency said. In particular, this sub-lineage has been more difficult to identify with PCR tests, hence its “stealth” nickname. The BA.2 variant is now present in 57 countries and preliminary data suggest it has higher transmission than BA.1. While that is concerning, the same preliminary data show that vaccines continue to be effective. The WHO asks for more investigations into this sub-lineage to truly assess its characteristics to guide response strategies for addressing the continuing pandemic. As of Sunday, over 370 million confirmed cases and over 5.6 million deaths have been reported across the world. Source