Although serious illness and hospitalization from severe COVID are remarkedly low, the recent rise of Omicron Subvariant XBB.1.5 is highly concerning.
First detected last October in the US, XBB.1.5 has been circulating in at least 38 countries, including Canada, Australia, Kuwait, Germany, and France, and now accounts for 43% of the COVID-19 cases in the US for the week ending Jan 14, a sharp rise from only 27.6% and 18.3% for the week ending Jan 7 and Dec 31 respectively.
XBB.1.5, unofficially named Kraken, is a combination of two strains of the subvariant BA.2. On Jan 4, WHO called this the “most transmissible subvariant detected yet”. WHO has no definitive evidence that Kraken will lead to more severe disease than its predecessors. However, since the mutations within this subvariant of Omicron allow this virus to adhere to the cell and replicate more quickly, scientists warn everyone to be highly vigilant till definitive evidence arises in either direction.
Since the bivalent vaccine, which includes a combination of the original virus and the Omicron variant, continues to provide “good protection” including against XBB strains in terms of preventing severe acute disease, scientists urge everyone to get boosted ASAP.