Study Identifies Virological Characteristics Of The SARS-CoV-2 KP.2 Variant, One Of The Variants Behind Spring’s Silent COVID-19 Surge

COVID-19 News: Many are unaware that there is currently a silent rise in COVID-19 infections occurring in parts of United Kingdom, Netherlands, Germany, France, United States, India, China, Japan, Australia, Russia, Iran and New Zealand.


Study Identifies Virological Characteristics Of The SARS-CoV-2 KP.2
Variant, One Of The Variants Behind Spring’s Silent COVID-19 Surge
 
Government authorities are simply downplaying or concealing the statistical COVID-19 data and mainstream media have been bought to refrain from writing too much about these rising infections. Even by reducing testing and changing to waste-waste monitoring companies that are more compliant to government policies, many independent sources are still clearly indicating a rise of infections.
 
Unfortunately, even search engines are now shadow-banning or lowering the news feed exposure of any COVID-19 News coverages that report about rising COVID-19 cases in any geolocations!
 
What is worrying however is that the rise of the new COVID-19 waves are being driven by a totally new line of SARS-CoV-2 JN.1 spawns including the KP variant with its lineages like KP.1, KP.1.1, KP.1.1.1, KP.2, KP.2.2 KP.3, KQ.1, KS.1 and KR.1.
 
Most of these new variants are also known at the FLiRT variants and spot the mutations F456L and R346T which give them an effective growth advantage over other circulating variants and are more immune evasive and transmissible.
 
The KP variants in particular are behind the new COVID-19 surges that are underway and are expected to play a key role in this Spring’s surges.
 
The ongoing evolution of the SARS-CoV-2 virus has led to the emergence of various variants, each with unique characteristics influencing its transmissibility, virulence, and immune evasion. Among these variants, the KP.2 variant, a descendant of the JN.1 lineage, has garnered attention for its rapid spread and potential impact on public health.
 
A new study by researchers from the University of Tokyo-Japan, Kobe University-Japan, Keio University School of Medicine-Japan, Tokyo Medical and Dental University-Japan, Tokyo Metropolitan Institute of Public Health-Japan, Kumamoto University-Japan and MRC-University of Glasgow Centre for Virus Research-UK delves into the virological features of the SARS-CoV-2 KP.2 variant, shedding light on its genetic makeup, fitness advantages, and immune evasion strategies.
 
Evolutionary Trajectory of the JN.1 Variant
The JN.1 variant, originating from the BA.2.86(.1) lineage with the S:L455S substitution, demonstrated increased fitness and successfully outcompeted the previously dominant XBB lineage by early 2024. This evolutionary success led to the diversification of the JN.1 lineage, giving rise to progenies with key spike protein substitutions such as S:R346T and S:F456L. Notably, one of these progenies, the KP.2 variant (JN.1.11.1.2), emerged as a rapidly spreading variant in multiple regions by April 2024.
 
Genetic Composit ion of the KP.2 Variant
The KP.2 variant carries three notable substitutions in the Spike (S) protein, including S:R346T and S:F456L, along with an additional substitution in non-S protein regions compared to its precursor JN.1. These genetic alterations are crucial in understanding the variant's biological behavior and potential impact on transmission dynamics.
 
Enhanced Fitness and Epidemiological Impact
Through Bayesian multinomial logistic modeling based on genome surveillance data from the USA, United Kingdom, and Canada, the relative effective reproduction number (Re) of KP.2 was estimated. The analysis revealed that KP.2 exhibits 1.22-, 1.32-, and 1.26-fold higher Re values compared to JN.1 in the respective countries. These findings indicate a higher viral fitness for KP.2, suggesting its potential to become the predominant lineage globally.
 
Spread and Frequency Dynamics
By the beginning of April 2024, the estimated variant frequency of KP.2 had already reached 20% in the United Kingdom, indicating its rapid dissemination within a short timeframe. This escalating frequency underscores the variant's ability to outcompete existing lineages and establish itself as a significant contributor to the ongoing pandemic dynamics.
 
Infectivity and Immune Resistance
In terms of infectivity, KP.2 demonstrated a significant 10.5-fold decrease in infectivity compared to JN.1, as observed in pseudovirus assays. Furthermore, neutralization assays using sera from monovalent XBB.1.5 vaccinees and individuals with breakthrough infections highlighted KP.2's heightened resistance to neutralization. The 50% neutralization titer (NT50) against KP.2 was notably lower than that against JN.1 across all tested scenarios, indicating a reduced susceptibility to vaccine-induced and infection-acquired immunity.
 
Implications for Public Health and Vaccination Strategies
The findings regarding KP.2's increased immune resistance and higher Re values have critical implications for public health interventions and vaccination strategies. The variant's ability to evade neutralizing antibodies to a greater extent than previous variants, including JN.1, necessitates ongoing surveillance, rapid variant characterization, and potential adjustments to vaccine formulations or booster strategies to maintain efficacy against evolving strains.
 
Conclusion
In conclusion, the SARS-CoV-2 KP.2 variant exhibits distinct virological characteristics, including enhanced fitness, rapid spread, reduced infectivity, and increased immune resistance. Understanding these features is paramount in effectively managing and responding to the ongoing COVID-19 pandemic. Continued genomic surveillance, coupled with proactive public health measures and adaptive vaccination campaigns, remains essential in mitigating the impact of emerging variants like KP.2 and ensuring optimal control of viral transmission.
 
The study findings were published on a preprint server and are currently being peer reviewed.
https://www.biorxiv.org/content/10.1101/2024.04.24.590786v1
 
Thailand Medical News would like to add that why we think that these KP variants are more worrisome is because not only are they more immune evasive but they are believed to be better at disarming all the initial host immune responses and are suited for viral persistence. However, as they are also good at disarming the specific immune response in various reservoir segments across the body, they can silently cause enough cell, tissue and critical cellular pathway damage in these areas before actual symptoms manifest signifying a serious problem. We can expect to see a higher incidence of various organ failures and sepsis from these variants along with other serious medical issues.
 
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