The Kraken Variant |

COVID-19 continues to develop new forms of the Omicron strain, which is the predominant form of the virus circulating today. Much more contagious than the original novel coronavirus found in Wuhan, China in late 2019, the omicron strain has continued to mutate; there are now more than 650 subvariants, and that doesn’t include the previous Greek-letter versions like Alpha, Gamma, Delta, and their subtypes.

(Aside: The term “omicron,” was given to the strain purposefully even though the next assignable letter in the Greek alphabet was actually “Xi.” Given the similarity to the name of the Chinese head of state, scientists skipped to the letter after that, “omicron,” to avoid a diplomatic incident.)

Certain subvariants that are concerning are now being given names from Greek lore. The current mutation, XBB1.5, that is showing growth in the United States is being called the “Kraken” variant, after the mythological sea monster.

The Kraken variant is thought by the World Health Organization (WHO) to be the most transmissible version yet, with possible reproductive (R-Nought) numbers above 18. A disease’s R-Nought is the number of cases that will occur in a vulnerable population if an infected person is placed in the middle of it. Measles’ R-nought is about 18, which means that an infected individual will give the disease to an average of 18 susceptible people. The Kraken variant is apparently even more contagious.

Actually, there hasn’t been an official R-nought given to XBB1.5 as far as I know, but it is contagious enough to displace previous high-level contagious subvariants like BA-5 (R-Nought of 18.5) and BQ1.1, meaning that it must have a higher number. This would make it the most contagious virus ever known. Dr. John Sader, a physician with a genetics background, emphasizes, however, that theoretical R-Nought isn’t necessarily what happens in the real world.

Having said that, he was alarmed when the scientific community stopped using R-Noughts as a statistic. He said: “On the world scientific stage, there was a decision last week to stop speaking about R-Noughts’s!!!! I hope it’s because Real World R-Noughts are difficult to follow and not because it is a politically-motivated decision.”

In any case, the Centers for Disease Control and Prevention (CDC) notes that the very contagious XBB1.5 made up 27 percent of US cases for the week ending on January 7^th,a major increase from the month before. More than 70 percent of cases in the Northeast are now believed to be the Kraken variant.

Some researchers believe omicron’s descendants are more able to evade antibodies than earlier version, while binding more tightly to cells and replicating faster.

It’s still unknown as to whether the Kraken variant, which evolved when two previous omicron subvariants exchanged parts of their genome, causes more severe disease than previous subtypes. Hospitalizations have risen but are still far below the level of a year or so ago.

The White House states that to have much protection against XBB1.5, you need either to have had a very recent vaccine or infection with the virus. Some concerns among scientists exist because lab studies show that antibodies generated by vaccines have difficulty blocking the variant. They still seem to provide added protection against severe illness.

Paul Offit, director of the vaccine education center at the Children’s Hospital of Philadelphia, states: ““At some level, we are going to have to get used to mild illness unless you want to take three doses a year and stay in your house most of the time.”

The sickest COVID patients are still those who are elderly, have a weakened immune system, or a lot of medical problems. XBB1.5 is a concern, but it’s not the most severe form of COVID we’ve seen. The bottom line: You can’t assume you won’t get sick again if your last infection or injection was more than a few months ago. If there are situations where you’re in large crowds indoors, consider wearing N95 masks or, at least, ask yourself: “Do I really need to be here?”

Joe Alton MD