All you need to know about the 'stealth' Omicron variant

Following easing of restrictions, COVID cases are on the rise again. China recently imposed restrictions to curb the spread of cases while South Korea recently reported over 6 lakh cases. The World Health Organisation (WHO) has called the recent surge in cases 'tip of the iceberg'.

The outbreak of the new variant, 'stealth' sub-variant of Omicron has many worried. Israel recently confirmed two cases of the new variant in two passengers who arrived at the Ben Gurion airport.

• The lesser known BA.2 variant is also likely to have the same severity as the 'original' Omicron strain, according to the World Health Organization (WHO). WHO has emphasised that BA.2 should continue to be monitored as a distinct sub-lineage of Omicron by public health authorities.

• It further added that the initial data from population-level reinfection studies shows that reinfection with BA.2 following infection with BA.1 provides strong protection against reinfection with BA.2.

• There have been concerns about the difficulty in detecting the BA.2 variant, or the stealth sub-variant of Omicron. The new variant misses key mutations in spike protein, which are generally necessary for rapid PCR tests to identify the infection. It combines two sub-variants of the Omicron version of the Covid virus named BA.1 and BA.2.

• The variant primarily affects the upper respiratory tract, as per WHO. However, like Delta, the BA.2 variant does not affect the lungs, eliminating symptoms such as loss of taste or smell, and shortness of breath.

• Patients affected by this variant have reported dizziness and extreme fatigue. These symptoms are likely to appear within two to three days after being infected with the virus. Other symptoms may also include fever, coughing, sore throat, sore hand, muscular fatigue, cold, and elevated heart rate.

WHO said there were more than 11 million new COVID-19 infections last week - about an 8% rise - and 43,000 new deaths. The number of COVID-19 deaths globally has been dropping for the past three weeks.

The biggest increase in cases were seen in the Western Pacific and Africa, where infections rose by 29% and 12% respectively. Elsewhere, cases dropped by more than 20% in the Middle East, Southeast Asia and the Americas. In Europe, cases inched up by about 2%.

WHO said those numbers “should be interpreted with caution.” It noted that many countries are changing their COVID-19 testing strategies as they exit the acute phase of the pandemic, and are testing far less than previously, meaning that many new cases are going undetected.

In recent weeks, countries including Sweden and the UK have announced plans to drop widespread testing for COVID-19, saying the massive investment is no longer worth the effort. Still, infections, hospitalisations and deaths have increased slightly in Britain, driven by the more infectious omicron subvariant BA.2. Another contributing factor has been the suspension of nearly all COVID-19 protocols as more people abandon masks and gather in larger numbers.

WHO noted that although COVID-19 has been dropping in numerous regions, the Western Pacific has seen rising numbers since December.

China banned most people from leaving a coronavirus-hit northeastern province and mobilized military reservists Monday, as the fast-spreading “stealth omicron” variant fuels the country's biggest outbreak since the start of the pandemic two years ago. Officials also locked down the southern city of Shenzhen, which has 17.5 million people and is a major tech and finance hub that borders Hong Kong — which itself has reported some of the highest COVID-19 death rates recently.

(With inputs from agencies)