Winter has started with very mild temperatures; until this week, that the cold weather is already here. RSV (Respiratory Syncytial Virus), which causes bronchiolitis and the flu have passed their epidemic peak. However, for the moment COVID is stable. Due to this combination of viruses in the environment, the health system has been under pressure for weeks, especially the Emergency services.
Right now, experts' eyes are turning to China, which has abruptly ended its zero COVID policy, and to the US, where a new variant of Omicron is causing concern. The XBB variant appeared from the combination of two Omicron variants, as part of their genetic material was exchanged. Now, a mutation has given rise to the XBB.1.5 or Kraken variant, detected for the first time in October 2022 in the US. This variant is new, but it's still Omicron.
In the US, this variant has shown greater transmissibility with more reinfections. According to laboratory data, it is more resistant to monoclonal antibodies commonly used as treatment, but antivirals seem to maintain their efficacy.
Kraken’s Seriousness and Capacity to Spread
Clinically, it behaves like the Omicron variants at the moment that have dominated the recent scene. If the number of cases were to increase a lot, there could be a proportional increase in hospitalisations, given its transmissibility; and this would translate into a greater burden for the health system. Kraken has already been detected in several EU countries, although at very low levels. It is spreading rapidly in the USA. Some predictive models indicate a moderate probability of it becoming the dominant variant in the EU in 1-2 months; however, the scenarios are different for each country and uncertain at this time.
Vaccine effectiveness and protective measures
There are still insufficient data to know how effective current vaccines are against the Kraken variant, but they are effective in maintaining immunity, especially with the bivalent booster. They make it possible to reduce severe and very severe forms of COVID.
The measures to be taken at this time are: follow the evolution of the virus and identify the variants circulating; remain calm and reinforce the wall of immunity that the population has built through vaccines; and continue with basic prevention measures.
The booster dose is especially important in people at higher risk: those over 60 years of age, pregnant women or patients with serious underlying diseases as well as healthcare personnel. Receiving the second booster dose, with an updated bivalent vaccine, poses less risk of contagion, hospital admission and severe forms of COVID.