Two teams of American scientists have recently conducted laboratory experiments aimed at evaluating the effectiveness of antibodies from both vaccinated and previously infected individuals against the various circulating variants of the COVID-19 virus. Among these variants is the highly mutated BA.2.86, also known as Pirola.
Remarkably, the results from both research groups closely aligned, particularly in the case of BA.2.86. The findings suggest that our immune systems can effectively recognize and combat this variant, potentially even more efficiently than some of the current offshoots of the XBB variant. Intriguingly, individuals who exhibited the strongest immune responses against BA.2.86 were those who had recovered from an XBB subvariant infection within the past six months. This suggests that the forthcoming updated COVID-19 vaccines for the fall, designed to target XBB.1.5, may offer enhanced protection against a range of circulating COVID-19 lineages, including BA.2.86.
Dr. Dan Barouch, who heads one of the research labs at the Center for Virology and Vaccine Research at Beth Israel Deaconess Medical Center, noted, “Two independent labs have basically shown that BA.2.86 essentially is not a further immune escape compared with current variants.”
These findings corroborate earlier experiments conducted by labs in China and Sweden, collectively indicating that BA.2.86 may not pose the substantial threat initially feared. In essence, BA.2.86 might not be as concerning as initially believed.
However, another variant, FL.1.5.1, responsible for an estimated 15% of new COVID-19 infections in the US, raises different concerns. This fast-spreading descendant of the XBB recombinant variant has a collection of mutations that have garnered attention from variant researchers for their potential immune-evading properties.
Both research groups conducted their experiments using blood plasma samples from individuals who had received monovalent or bivalent vaccines, as well as those who had recently recovered from XBB infections. In both cases, the antibodies present in the samples demonstrated the ability to neutralize BA.2.86 as effectively, and sometimes even more effectively, than other circulating variants. Those who had recently recovered from XBB infections displayed the highest levels of immunity against BA.2.86.
Despite the surprising results, scientists conducted extensive verification to confirm their findings. Dr. Barouch expressed confidence in the results, emphasizing their importance. He has been invited to brief the White House and the US Centers for Disease Control and Prevention on these significant findings.
Researchers worldwide are actively conducting laboratory experiments to gain a deeper understanding of the BA.2.86 variant. Four separate groups, including the two American teams and laboratories in China and Sweden, have reported their findings. Early results collectively suggest that BA.2.86 may not be the formidable adversary it initially appeared to be. Nonetheless, ongoing research will provide further insights.
BA.2.86 gained global attention due to its distinctiveness from other known coronavirus variants. It possesses over 30 spike protein changes compared to its closest ancestors, BA.2 and XBB.1.5, making it an evolutionary leap similar to the original Omicron variant’s emergence nearly two years ago.
During the Omicron wave, the United States experienced its highest infection and hospitalization rates, emphasizing the potential threat posed by even less severe virus variants if they lead to widespread infections. Vaccines had to be adapted accordingly.
Despite initial concerns, experts believe that BA.2.86 may not be as menacing as initially thought, and it is unlikely to be the “second coming of Omicron.” The White House had sought expert opinions on the likelihood of another Omicron-level event, with most experts estimating a relatively low probability.
While BA.2.86 has appeared in multiple countries, genetic surveillance suggests it has not become dominant. Experts believe it will circulate gradually but will not outcompete other prevailing variants.
Studies on BA.2.86 have limitations, as researchers used pseudoviruses rather than the actual virus and relied on small sample sizes. Additionally, the immunity profiles of individuals in China and Sweden may differ from those in the United States.
Nonetheless, early results have provided reassurance, suggesting that upcoming vaccines may offer significant protection against both the dominant EG.5 variant and BA.2.86. The UK’s Variant Technical Group is closely monitoring the situation and awaits additional data and results from international partners.
In summary, recent laboratory experiments indicate that BA.2.86 may not pose the severe threat initially feared, and vaccines should still provide substantial protection. Further research and data will continue to shed light on the variant’s behavior and impact.