The Omicron variant represented 47.2 per cent of Covid-19 infections in Spain in the week of 6 to 12 December, according to the initial data from 125 random samples from six regions, which health officials described as "still very preliminary and not very representative at the national level".
This was detailed in the 'Update of the epidemiological situation of the variants of SARS-CoV-2 in Spain', published on Monday, 20 December, by the national ministry of health, which pointed out that the percentage of the Omicron variant cases in the total number of infections has multiplied exponentially, as it was only responsible for 3.4 per cent of the randomly sequenced samples in the week of 19 November to 5 December.
"In Spain it has gone very quickly from being detected in cases associated with travellers from southern Africa to cases linked to community transmission,” said the ministry.
It added that the Delta variant, predominant until the beginning of December, "is currently being displaced by Omicron". According to the sequencing data, in the week of 29 November to 5 December, the percentage for Delta was 92.4, while in the following week, which began with the Constitution Day public holiday, it accounted for only 51.2 per cent, although the Health ministry points out that it is "still very preliminary data".
The department noted that "data are still very scarce to determine the true impact of the Omicron variant on the epidemiological characteristics of the infection, but preliminary studies point to greater transmissibility and greater immune escape." "There is still a high level of uncertainty regarding possible changes in the severity of the cases," it added.
Meanwhile, other remaining variants continue to be detected at "very low" levels. In fact, in the last four weeks analysed, only 39 of 2,870 sequenced random samples correspond to variants other than Delta or Omicron.