A study published this Wednesday by the scientific journal The Lancet confirms that no new variant of the coronavirus that causes covid-19 was detected in China during the outbreak at the end of 2022.
According to the study, which corroborates the findings of the World Health Organization (WHO), the BA.5.2 and BF.7 subvariants of the Omicron variant of SARS-CoV-2 dominated in the Chinese capital, Beijing, between November 14 and on December 20. , 2022, jointly contributing to more than 90% of local infections.
On January 4, the WHO had indicated that the same subvariants, which circulate in other countries, also contributed, together, to more than 90% of the infections acquired in China and whose genetic data was collected since December 1.
China, where SARS-CoV-2 was detected at the end of 2019, ended on December 7 with Covid-19 control policies that included confinement, mass testing and quarantines.
As a result of the easing of the measures, added to the lack of efficacy of Chinese vaccines and the low number of vaccinated population, infections and deaths increased in China at a galloping rate at the end of 2022, which led to several countries, including Portugal, to impose restrictions. in travelers from China, such as trying on and wearing a mask.
According to the study published this Wednesday in the British journal The Lancet, the subvariants BA.5.2 and BF.7 were already circulating, however, in a significant way in Beijing even before the end of the Chinese “zero covid” policy.
The study, carried out by scientists from several Chinese institutions, was based on the analysis of 413 SARS-CoV-2 genetic sequences from infected people.
Of the total genomic sequences analyzed, 350 corresponded to locally transmitted infections in China and 63 to imported cases from the same number of countries.
Although limited to Beijing, the study found that the population of the BA.5.2 and BF.7 subvariants increased after November 14, with BA.5.2 and BF.7 accounting for 16.3% and 75.7%, respectively. % of local infections.
While BF.7 gradually increased from November 14, BA.5.2 increased sharply from November 30, the Lancet article notes.
Opposing mandatory Covid-19 screening in the European Union (EU) for travelers from China, on December 29, the European Center for Disease Prevention and Control highlighted that EU countries had “levels of relatively high immunization and vaccination rates” and that the SARS-CoV-2 variants prevalent in China were already circulating in the EU.
Covid-19 is an infectious respiratory disease caused by the SARS-CoV-2 coronavirus, a type of virus that was detected three years ago in China and has spread rapidly throughout the world, assuming several variants and subvariants, some of which are more contagious. what others. .
Since March 11, 2020, Covid-19 is a pandemic and since January 30, 2020, an international public health emergency.
Source: TSF
