XBB.1.5 Omicron: The Rapidly Spreading COVID-19 Sub-Variant Raising Concerns About Vaccine Effectiveness
The emergence of the XBB.1.5 Omicron subvariant of the SARS-CoV-2 virus has caused alarm among scientists and public health officials due to its rapid spread and potential impact on the effectiveness of vaccines. The XBB.1.5 subvariant has been identified in the United States and the United Kingdom and has rapidly become the dominant strain in the US in recent weeks.
According to data from the Centers for Disease Control and Prevention (CDC), XBB.1.5 now accounts for approximately 40.5% of new COVID-19 cases in the US, nearly doubling in prevalence over the past week. This marks a significant increase from the 21.7% recorded the week prior and has caused the XBB.1.5 to surpass the BQ.1 and BQ.1.1 subvariants as the most prevalent strain in the country. In the UK, XBB.1.5 is already responsible for approximately one in 25 cases, according to surveillance data.
The XBB.1.5 subvariant was first detected in New York and has since spread to over 70 countries, including India and Singapore. It is believed to have emerged from mutations in the XBB variant, which itself likely resulted from the combination of the BA.2.10.1 and BA.2.75 subvariants. The XBB variant was first identified in India in August and has rapidly become dominant in several countries.
The rapid spread of the XBB.1.5 subvariant has raised concerns that it may have a “growth advantage” over other strains, potentially making it more transmissible or better at evading immune protection. This has led to fears that current vaccines may not be as effective against the XBB.1.5 subvariant, though more research is needed to confirm the extent of any potential impact.
In addition to its potential impact on vaccines, the XBB.1.5 subvariant has also been found to be resistant to Evusheld, an antibody cocktail often used by individuals with weak immune systems who do not mount a strong response to vaccines. This resistance to antibodies from both vaccination and infection is particularly concerning and highlights the constantly evolving nature of the COVID-19 pandemic.
The emergence of new subvariants like the XBB.1.5 emphasizes the importance of continuing efforts to reduce the spread of the virus, including the use of face masks and other precautions. It also highlights the need for ongoing vigilance in monitoring and tracking new variants to ensure that public health measures and vaccines can be adjusted accordingly. As the XBB.1.5 subvariant continues to spread and potentially evolve, it will be crucial for scientists and public health officials to closely monitor its impact and work to understand its characteristics to combat the ongoing threat of COVID-19 effectively.