The Pirola Subvariant Less Infectious than Feared, Say Scientists

The new Pirola subvariant may be significantly less infectious than feared despite a substantial rise in Covid cases this month, scientists say. Instead, experts argue that waning immunity, cooling weather, and people going back to work and school after holidays are likely to be the main drivers of the increase.

Rise in Covid Cases and Expectations for the Future

Symptomatic Covid cases have jumped by nearly 50 per cent this month, with approximately 1.3 million people in the UK estimated to be infected, according to the ZOE Health Study. Experts expect cases to increase further in the coming weeks with the onset of autumn and winter.

The Genetic Profile of Pirola and its Impact on Spread

Pirola has 34 genetic mutations compared to its parent, Omicron, leading to fears that it would be more effective at evading immunity built up from previous infections and vaccinations and consequently spread more rapidly. However, an analysis of data on the GISAID global Covid database suggests that Pirola only accounts for about 0.25 per cent of Covid cases worldwide, according to Professor Francois Balloux, director of the UCL Genetics Institute. Furthermore, this number may have even decreased over the past two weeks. However, the margin of error in calculations makes it difficult to provide precise figures.

Low Prevalence of Pirola in the UK

Despite a high-profile outbreak in a Norfolk care home, Pirola accounts for no more than 0.5 per cent of Covid cases in the UK. Its estimated frequency remains relatively low in the country.

Determining the Infectiousness of Pirola

Although changes in the frequency of Pirola suggest it may not be as infectious as initially thought, preliminary scientific studies offer mixed results. Professor Lawrence Young, a virologist at the University of Warwick, highlights the controversial nature of determining the infectiousness of Pirola. Initial lab data suggests relatively low infectivity compared to other Omicron variants, but testing in another cell line contradicts these findings. Further research and observation are necessary to fully understand the transmissibility of Pirola.

Potential Pathogenicity of Pirola

While it is too early to predict the pathogenicity of Pirola in different populations, Professor Steve Griffin of Leeds University notes that studies conducted in the lab using pseudotypes suggest Pirola does not infect cells as efficiently as other variants. However, it’s worth highlighting that Pirola has spread successfully, indicating some level of transmissibility.

In conclusion, the new Pirola subvariant may not be as infectious as initially feared. Despite a rise in Covid cases, experts point to other factors such as waning immunity and seasonal changes as the main drivers of the increase. While the prevalence of Pirola remains relatively low globally and in the UK, further research is needed to determine its exact transmissibility and potential pathogenicity.