The BA.2 sub-variant of the omicron variant of the coronavirus is spreading rapidly around the world.
According to the World Health Organization (WHO), it has now become dominant globally, representing nearly 86 percent of all sequenced cases. First detected in the early days of January, BA.2 is even more transmissible than BA.1 and BA.1.1 sub-variants.
BA.2 is slightly harder to track. So, it is often referred to as the stealth variant. BA.2 can only be found by genomic sequencing. Even though BA.2 is more infectious than other Omicron sub-variants, evidence suggests that it is not more likely to cause severe disease.
Vaccines are less effective against BA.2 than they are against other variants like Alpha or the original strain of coronavirus. Also, the protection declines over time. Protection is restored by a booster jab, particularly for preventing hospitalization and death.
Omicron can re-infect people who had other variants, such as Delta. But only a handful of BA.2 reinfections in people who had BA.1 have been found so far among tens of thousands of cases.
