(ANSA) - ROME - People who have become infected with Omicron BA.1 in recent months, even if vaccinated, could be vulnerable to the new sub-variants BA.4, BA.5 and BA.2.12.1.
Furthermore, "a BA.1-derived booster vaccine may not provide broad-spectrum protection against new Omicron variants."
This is the conclusion reached by Chinese researchers coordinated by Peking University in a study published in Nature.
The research studied the genetic evolution that the Omicron variant underwent in recent months, investigating the specific mutations of each sub-variant and the world in which antibodies developed following vaccination or previous infections were able to recognize them.
BA.4, BA.5 and BA.2.12.1, the researchers explain, have many similarities with the sub-variant BA.2.
However, unlike this, the mutations accumulated by the new sub-variants gave them a greater ability to evade the immune response developed after a BA.1 infection, even in those who received three doses of the vaccine.
"This phenomenon - they write - seriously questions the idea of herd immunity obtained through vaccination against the original virus and BA.1 and BA.2 infection".
A hypothesis that seemed, at least temporarily, plausible given the high vaccination coverage achieved in many countries alongside the high infection rates due to Omicron.
(HANDLE).
