As autumn approaches, researchers announce that they have discovered a new sub-variant of Covid-19. Called XEC, this mutation has already appeared in several European countries such as the United Kingdom or Denmark, Slovenia, but also in the United States. This variant results from a hybrid combination between two sub-variants of the infamous Omicron family previously discovered, namely KS.1 and KP.3. It is also the latter that had created the last epidemic resurgence.
What vaccine response?
Even though the symptoms associated with this sub-variant seem to be much the same as those associated with the circulation of previous variants, namely: fever, sore throat, cough, loss of smell, loss of appetite and body aches, the question that arises obviously concerns the effectiveness of vaccines against this new variant. While the next vaccination campaign is due to start in the coming weeks, “we cannot answer in anticipation of vaccine effectiveness”, explains Benjamin Davido, head of the infectious diseases department at Garches hospital.
“But the good news is that the vaccines have been updated with the JN.1 variant from which the KP.3 variant was derived. As this new sub-variant (XEC) is a recombination from KP.3, we can say that if we project ourselves to next fall, this anticipation of vaccine update will allow us to have much more neutralizing antibodies.” Furthermore, it is possible that this new sub-variant has a significant contagious power. Indeed, recombination logically leads to a greater risk of transmission, because it makes it easier to escape immunity. But let’s be reassured, for the moment, the data provided by the CDC (Centers for Disease Control and Prevention, editor’s note) in the United States do not show a more serious form.
Towards annual vaccine updates
Nevertheless, the infectiologist insists on one point. “We have no decrease in the percentage of positive PCR tests and therefore in the circulation of the virus since the beginning of the summer, and that is unprecedented. It does not mean that we are going to start from very high and end up extremely high, but it does mean that the virus has found fresh blood”. For Benjamin Davido, there is a good chance that, just like the flu, we will see a need for a specific vaccine and an update every fall.
Furthermore, the fact that we are no longer in a critical situation does not mean that the virus has disappeared, hence the importance of continuing to pay attention to vaccination campaigns. “We are in a period following the most critical moment in the circulation of this virus and where there are no longer any phenomena of hospital saturation. But paradoxically, we are still under threat from this virus in the same way that we are still under threat from the flu every year.”
