Covid-19 vaccines may be less effective against Omicron: WHO

Preliminary evidence indicates that vaccines against Covid-19 They may be less effective against infection and transmission related to the Omicron variant of the coronavirus, which also carries a higher risk of reinfection, said Wednesday the World Health Organization (WHO).

In its weekly epidemiological update, the WHO said more data is needed to better understand the extent to which you can evade Omicron immunity derived from vaccines or previous infection.

As a result, the overall risk related to the new Omicron variant of concern remains very high, “he said, echoing comments made by WHO officials in an online briefing on Tuesday.

For the first time since the Delta variant was classified as a concern in April, the percentage of Delta sequences recorded in GISAID’s global scientific database has decreased this week compared to other variants of concern, he noted.

This should be interpreted with caution, as countries can perform omicron-directed sequencing and thus load fewer sequences in all other variants, including delta, he said.

However, delta remains dominant, accounting for 99.2% of the nearly 880,000 sequences uploaded to GISAID with samples collected in the last 60 days.

However, the trend is decreasing in the proportion of Alpha, Beta and Gamma, and with the appearance of omicron. Of the total, about 3,755, or 0.4%, were Omicron and the other three interest variants together totaled 401, less than 0.1% each.