Omicron has mutated again giving rise to a new sub variant XBB.1.5, which has raised concerns, as its rapidly spreading in many countries across the world.



The family of XBB is found to be more immune-evasive than any other variants. The mutations has made the virus bind better to the cells, making it more transmissible.



  • The period of infectiousness is similar to previous Covid sub variants. One remains contagious one to two days prior to development of the symptoms and alteast two to three days after the symptoms end. Isolation of 10 days is recommended

Previously infected with Omicron, can get reinfection with new variant:

  • People who have been infected by Omicron can get reinfected with XBB variant. As mentioned this sub variant is more immune- evasive and with time the natural immune response decrease.

What are the symptoms of the XBB1.5?

            Symptoms of fever, sore throat, body aches, runny nose, headache, diarrhea and chest congestion are similar to previous infections

Are the current antiviral therapies effective?

Paxlovid, the oral antiviral has shown to be somewhat effective in controlling severe infections and hospitalizations. However, the older monoclonal antibodies are not effective

Covid Bivalent vaccine is effective against the new variant:

The studies done so far have shown that bivalent is still effective in protecting against severe disease. The XBB variant is derived from Omicron variant BA.2, the bivalent vaccine though developed for variant B.5, its shown it does generate antibodies that recognizes BA.2, thus providing some level of protection against XBB sub variant.


It’s highly recommended to receive the bivalent (updated) vaccines for those who haven’t yet taken their shot.

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