The BA.2.86 variant, which was initially thought to be less transmissible and cause milder infections, is now showing signs of becoming a major player in the upcoming winter surge. This variant has been found to acquire FLip mutations, which can make it more immune evasive and increase the risk of severe disease and death. Researchers have already identified four sequences of the BA.2.86 variant with FLip mutations in four different countries, with the first case being detected in Iceland.
This variant, which has accumulated over 30 new mutations, continues to evolve rapidly and give rise to sub-lineages with concerning mutations. It has been detected in wastewater samples from various locations and has been identified in 24 countries so far. Genomic sequences uploaded on GISAID, a global database for sharing genomic data, indicate that the BA.2.86 variant is associated with increased disease severity, as approximately 68 sequences were obtained from hospitalized patients.
The emergence of the BA.2.86 variant, along with other new variants, is expected to contribute to a severe winter surge in the upcoming 2023/2024 season. Contrary to earlier misinformation, it is now clear that the virus is more widespread and has the potential to become the predominant variant. It exhibits characteristics such as immune evasion, pathogenicity, fusogenicity (ability to merge with host cells), and high replication rates.
Although some studies suggest that COVID-19 vaccine boosters containing XBB.1.5 spike proteins are effective against the BA.2.86 variant, data from China paint a different picture. The presence of FLip mutations in the new BA.2.86 strains raises concerns that previous infections and vaccinations may not provide sufficient protection against this variant. This could potentially lead to increased disease severity and mortality.
As the BA.2.86 variant and its sub-lineages continue to evolve rapidly, it is crucial for public health authorities to closely monitor its spread and impact. Efforts should be made to enhance surveillance and genomic sequencing capabilities to detect and track the emergence of new variants. Additionally, research into the effectiveness of existing vaccines and the development of updated vaccines that target the BA.2.86 variant should be prioritized. It is essential to stay informed and follow public health guidelines to minimize the risk of infection and protect ourselves and our communities during this winter surge.