SARS-CoV-2 evolution from the BA.2.86 to JN.1 variants: unexpected consequences.

Area of Science:

• Virology
• Molecular Biology
• Epidemiology

Background:

• The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) constantly evolves, leading to new variants.
• The Omicron subvariant BA.2.86 emerged with over 30 spike (S) protein mutations, prompting expectations of global dominance.
• Despite predictions, BA.2.86 did not become the predominant strain.

Purpose of the Study:

• To investigate the unexpected epidemiological trajectory of SARS-CoV-2 Omicron subvariants.
• To provide a potential explanation for why BA.2.86 failed to become dominant and why its descendant, JN.1, rapidly emerged.

Main Methods:

• Comparative genomic analysis of SARS-CoV-2 variants.
• Analysis of epidemiological data and viral evolution trends.
• Hypothesis generation based on observed mutational changes and their potential impact.

Main Results:

• The Omicron subvariant BA.2.86, despite numerous mutations, did not achieve global predominance.
• The descendant strain JN.1, with a single additional mutation compared to BA.2.86, has become the predominant SARS-CoV-2 subvariant.
• The study proposes an explanation for this evolutionary outcome.

Conclusions:

• Viral evolution can lead to unpredictable outcomes in the SARS-CoV-2 pandemic.
• Minor genetic changes in key viral proteins, like the spike protein, can significantly influence transmissibility and dominance.
• Further research is needed to fully understand the factors driving the emergence and spread of new SARS-CoV-2 variants.