Electron micrograph of transmission of SARS-CoV-2 virus particles (in green) within the endosomes of a highly infectious nasal olfactory cell. (Photo: NIAID)
Since the beginning of December, the international scientific community has been monitoring BA.2, a subset of the omicron variant of Sars-CoV-2 in the last month of 2021, for the absence of a mutation in the S gene that allowed the rapid detection of stress in RT-PCR tests. While there are still more questions than answers, experts have also noted that it is gaining ground among sufferers.
Last Thursday (20), Denmark’s Statens Serum revealed that in the 52nd week of 2021 (27th week of December), BA.2 represented 20% of all Covid-19 cases in the country. In the second week of 2022, this version of omicron was responsible for 45% of diagnoses. During this period, the frequency of the BA.1 subspecies decreased.
According to the Danish Institute, there are more differences between BA.1 and BA.2 than similarities, even though they are considered to be the same variable. “In fact, the difference between BA.1 and BA.2 is greater than the difference between the original variable [identificada em Wuhan, na China, em 2019] and the alpha variable [detectada no Reino Unido em novembro de 2020]’, Diz o Statens Serum, in the note.
The concern is that these differences may indicate changes in SARS-CoV-2 infection, the efficacy of vaccines or even the severity of Covid-19. It should be noted, however, that this has not yet been proven.
Cases outside the UK
On The report was published on January 14The UK’s Health Security Agency said it is separately monitoring the omicron’s BA.2 subline. According to the agency, on January 1, 2022, this version of the strain represented 5% of positive tests for Covid-19, but that rate has been increasing since then.
With this, the British agency considers that the identification of the variant by a PCR test is “no longer sufficient to assess the prevalence of the omicron as a whole”, given the fact that the underlining was not detected in the procedure.
Last Wednesday (19) virologist Tom Peacock of the Department of Infectious Diseases at Imperial College London, Report any Twitter That BA.2 already accounts for the majority of cases in parts of India and the Philippines. “Very early observations* in India and Denmark indicate that there is no significant difference in intensity compared to BA.1,” Peacock wrote, adding that more data is expected in the coming weeks.
“So how worried should we be? Those who work in sequencing/observation should be watching BA.2 (and most likely they already do!), suggests the expert.” Personally, I am not sure that BA.2 would have much of an impact on The current wave of the omicron of the epidemic,” Peacock speculates.
