Göttingen, Germany, 9 January 2024. Despite the end of the pandemic, COVID-19 continues to pose a serious health threat. Most individuals have established robust immune protection and do not develop severe disease but the infection can still lead to marked and sometimes long-lasting disease symptoms. In the late summer of 2023 a new SARS-CoV-2 variant emerged, BA.2.86 (Pirola), which, based on genetics, differs markedly from all previously circulating variants.
A team of researchers from the German Primate Center (DPZ, Göttingen), jointly with partners at Charité (Berlin), Hannover Medical School, Helmholtz Centre for Infection Research (Braunschweig) and Friedrich-Alexander-University Erlangen-Nuremberg has now investigated the biological properties of the new variant. The researchers discovered that the Pirola variant, in contrast the all previously circulating Omicron variants, enters lung cells with high efficiency and uses the cellular enzyme TMPRSS2 for entry, thereby exhibiting surprising parallels to variants Alpha, Beta, Gamma and Delta that circulated during the first years of the pandemic.
The improved entry into lung cells might indicate that the virus is more aggressive but production of new, infectious viral particles in infected cells was reduced, which may limit spread and pathogenic potential. Finally, the researchers report that the Pirola variant is resistant against all therapeutic antibodies and efficiently evades antibody responses in vaccinated individuals with and without breakthrough infection. However, the virus was appreciably inhibited by antibodies elicited by the new, XBB.1.5-adpated mRNA vaccine. In summary, the results show that four years after the start of the pandemic the virus is still capable of profound changes and can reacquire properties which may promote the development of severe disease (Cell).
