PJSC “SPC “Diaproph-Med” constantly monitors SARS-CoV-2 mutations and the emergence of new
variants of the virus in order to improve the design of test systems to ensure maximum sensitivity and
The new strain SARS-CoV-2 was identified as AY.4.2. It is a descendant of the Delta variant (B.1.167.2)
and carries two characteristic mutations in the spike protein, Y145H and A222V.
Most of the SARS-CoV-2 mutations have independently occurred many times in unrelated strains. Both
Y145H and A222V spike mutations have been found in various other variants of SARS-CoV-2 strains since
the start of the pandemic, but still remain at a low frequency. The first strains carrying both mutations
were sequenced in April 2020. These mutations are not a priori obvious candidates for increasing viral
transmissibility, but we know that mutations can have different consequences, sometimes unexpected,
in different variants of the SARS-CoV-2 virus strains.
As it was written earlier, the use of conservative domains (sections) of the SARS-CoV-2 coronavirus
antigens in the design indicates the absence of a significant threat of reducing the diagnostic sensitivity
of test systems produced by PJSC “SPC “Diaproph-Med” to detect coronavirus disease due to mutations
and the emergence of new variants of strains SARS-CoV-2, including strain AY.4.2.
There is still not enough information about the new strain and work on its study continues.