A heavily mutated variant of the virus that causes Covid-19 appears to be affecting primarily children, scientists say, though it’s not causing more severe disease – in kids or in adults, reports BritPanorama.
Experts suggest the emergence of this variant, designated BA.3.2 and nicknamed “Cicada,” indicates a shift in the virus’s typical behaviour, which has mainly impacted older adults previously. This calls for increased study to enhance understanding of its evolutionary patterns.
Although Covid-19 is currently circulating at a low level, the United States is beginning to address the implications of BA.3.2, following its identification in late 2024. The US Centers for Disease Control reports that this variant has been detected in 23 countries and wastewater samples across 25 states. Despite reduced testing since the pandemic’s peak, the variant may be more widespread than indicated by current data.
Current vaccines are still believed to provide some protection against this variant, with reports from scientists suggesting its effects have been relatively mild, raising questions about the necessity for updated vaccines. “It’s super interesting from a viral evolution standpoint,” remarked Dr. Alex Greninger, head of Infectious Disease Diagnostics at the University of Washington. He noted that despite BA.3.2’s delayed movement, it may have negligible real-world impact.
Cicada’s disappearing routine
Scientists discussing naming conventions for Covid-19 variants often wait until a variant appears more likely to spread or garner public interest. Dr. T. Ryan Gregory from the University of Guelph mentioned that BA.3.2 was given a name after the World Health Organization designated it a “variant under monitoring” in December. The name “Cicada” reflects the unique pattern of this variant, which resurfaced after a prolonged silence.
BA.3.2 was first identified in South Africa in November 2024 and shows a substantial genetic divergence from its predecessors. This variant possesses 53 changes in its spike protein compared to BA.3 and approximately 70 mutations compared to the original virus. While it was initially detected in US travelers from the Netherlands in summer 2024, it has failed to demonstrate global dominance.
Despite numerous mutations, BA.3.2’s ability to effectively bind to ACE-2 receptors, essential for viral infection, appears compromised, limiting its competitive edge. It has yet to reflect in the national Covid-19 data, although experts believe it could see an uptick. Dr. Marc Johnson from the University of Missouri indicated that while BA.3.2 might dominate in the future, it remains a relatively benign variant at present.
In Germany, where BA.3.2 represented about 30% of new infections between November and January, signs of decline have emerged, suggesting the variant’s influence may be waning. Dr. Florian Krammer noted that although the initial rise in cases appeared alarming, the situation had stabilised, showing potential downturns.
Furthermore, vaccine efficacy against BA.3.2 was highlighted in a study conducted by Krammer’s team, showing that while some variants may evade neutralization, the updated vaccines effectively deal with this variant.
Infecting kids ‘quite efficiently’
Data patterns in the spread of Covid-19 are challenging to interpret due to a limited genetic sequencing of strains. However, emerging observations suggest BA.3.2 may infect children more effectively than adults. Dr. Tulio de Oliveira reported findings indicating children aged 3 to 15 years are particularly susceptible.
Analysis from New York City indicates that children are about five times more likely to be infected by BA.3.2 compared to other variants, although BA.3.2 itself still constitutes a minority within the larger variant landscape. Oliveira proposed that waning immunity from vaccines and past infections in younger populations may contribute to this trend.
Other experts suggest that genetic differences in the virus’s make-up might also play a role. BA.3.2 appears to lack specific genes critical for immune system activation, a characteristic shared with the XBB variant, which previously demonstrated increased prevalence among children.
In addition to genetic factors, Greninger illustrated that children’s immune systems may not be as diversified due to fewer prior exposures to Covid-19 compared to adults. This disparity could explain their heightened vulnerability to the variant.
Sharing a common environment, children in schools and daycares face a higher viral load, facilitating spread. Greninger noted the pattern of a variant infecting children resembles that of other seasonal respiratory viruses, suggesting that BA.3.2’s behaviour aligns with known trends in infectious disease transmission dynamics.
