Yet Another Worrisome New SARS-CoV-2 Variant B.1.1.523 Has Emerged In Russia And Now Spreading All Over Russia, Germany And Parts Of Europe
: Researchers from Maastricht University Medical Center-Netherlands and the South Limburg Public Health 9 Service-Netherlands has identified yet another new SARS-CoV-2 variant B.1.1.523 that most probably originated from Russia and that combines many spike mutations linked to immune evasion from current variants of concern (VOC). The worrisome variant is fast spreading in Germany and Russia and also certain parts of Europe according to the research report.
The study findings show that the new B.1.1.523 variant shares many spike mutations with current VOCs. Receptor-binding domain mutations E484K and S494P were observed as well as a deletion at position 156-158 in the N-terminal antigenic supersite that is similar to the delta-variant. These mutations are linked to immune evasion in VOCs that could lead to less effective vaccines. This variant has been reported in various different countries and continents despite the dominance of B.1.1.7 (alpha) and B.1.617.2 (delta) variant. Furthermore, the B.1.1.523 pangolin lineage as a whole is recognized as a variant under monitoring since the 14th of July 2021.
The study findings were published on a preprint server and are currently being peer reviewed. https://www.biorxiv.org/content/10.1101/2021.09.16.460616v1
Alarmingly, the study findings point to the fact that this new SARS-CoV-2 variant (B.1.1.523) is capable of escaping immune protections.
The SARS-CoV-2 outbreak has caused the ongoing COVID-19 pandemic in which the novel coronavirus has infected more than 233 million individuals globally and killed more than 4.76 million people so far while the figures keep rising despite the massive COVID-19 vaccination programme underway.
So far worldwide, more than 6.2 billion vaccine doses have been administered to various human life forms.
The SARS-CoV-2 coronavirus also continues to evolve owing to mutations, which have given rise to various SARS-CoV-2 variants.
As a result of continuous surveillance of the SARS-CoV-2 genome across the world, many variants have been detected that are more infectious and virulent than the original strain first reported in Wuhan, China in 2019. As the data on these variants are shared through the Global initiative on sharing all influenza data (GISAID) database, scientists are able to better understand the evolution of SARS-CoV-2.
The US CDC (United States Centers for Disease Control and Prevention) and the ECDC (European Centre for Disease Prevention and Control have classified emerging SARS-CoV-2 variants as variants of concern (VoC) or variants of interest (VoI).
Variants categorized as VoCs can cause severe COVID-19, increased rate of transmission, and can escape immune protection elicited via vaccine or natural infection. Some examples of known VoCs include the Alpha (B.1.1.7), Beta (B.1.351), Gamma (P1), and Delta (B.1.617.2) variants.
Past studies have reported that VoCs contain several mutations at the spike protein that are linked to immune evasion. In addition to the SARS-CoV-2 spike protein, neutralizing antibodies also target the receptor-binding domain (RBD) and N-terminal domain (NTD) of the virus.
Scientists have identified antigenic supersites in three regions of the NTD and
found that some antibodies can effectively target these antigenic super sites and neutralize them. Prior studies have indicated that mutation at the RBD region (e.g., E484K) can result in the evasion of immune responses.
The study team from Netherlands describes that the new B.1.1.523 variant
possesses a novel combination of various concerning mutations at the spike region. These mutations have been reported to be shared among VoCs.
The study team also revealed that the prevalence of this new variant has already been reported in many countries across the world.
Genomic specialist and virologists have defined the pangolin lineage of this variant to be B.1.1.523 and it was originally recognized as a variant under monitoring on July 14, 2021. According to GISAID, a total of 533 cases of B.1.1.523 have been reported as of August 19, 2021.
A large number of cases of this variant have been reported in Russia and Germany.
The growing prevalence of this variant has also been reported in the U.S. and Australia.
From the sequence-based surveillance data, it was found that the first cases concerning this variant were reported in February 2021 and was in Russia. However recognition of the first cases in Russia does necessarily implicates that this variant originated from this country although most scientists believe that the probability is rather high.
Interestingly the frequency of this variant increased in May 2021 and its prevalence decreased by June 2021. However it is started to become more prevalent again.
The study team has observed that this variant does not infect any specific age group.
The study team explain that it has not been easy to identify the origin of this variant by knowing the pangolin lineage and some spike mutations. Using the genomic sequences, they constructed a phylogenetic tree which revealed that all the cases were similar, as they were in the same branch. This result indicated that the origin of this virus was likely in Russia and the first strain was reported in Moscow.
Importantly two of the main reasons why scientists are concerned about this variant are the three amino acid deletions in the NTD antigenic supersite and the presence of the E484K mutation of the spike protein. The E484K mutation is also present in B.1.351 and P.1 variants, both of which are strongly associated with the reduced efficacy of vaccines.
The study team conducted multiple sequence alignment (MSA) with the amino acid sequence of VoC and the original SARS-CoV-2 strain.
The team found that three VoCs (Alpha, Beta, and Delta) have deletions in one of the regions of the NTD antigenic supersite. The deletion of B.1.1.523 was found to be similar to B.1.617.2 and also comprises the E484K mutation that is present in many VOC. The results of this study are in line with previous studies that reported the effect of spike mutations on the efficacy of monoclonal antibodies and convalescent plasma treatment.
The study team concludes that the new B.1.1.523 variant harbors a new combination of concerning spike mutations that are present in many currently circulating VoCs. Many of these mutations are concerning and are associated with the evasion of immune protection.
They added, “This is critical, as these developments could challenge the effectiveness of available vaccines. More research is required to determine the transmissibility of this variant, which would assist in the development of preventive strategies to stop the further spread of this strain.”
The coming highly anticipated winter COVID-19 surges are expected to be a real fun time as many potential key players have already been identified ie the R.I variant, the Delta AY.29 sub-variant, the B.1.1.519 variant, the Mu sub-variants and now also the B.1.1.523 strain plus Gawd knows what else! May be we will also see lots of cases of co-infections with more than one variant etc and maybe also get to witness more cases of ADE in the those that got the shots.
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