What is BF.7, the Omicron sub-variant driving the surge in China?

• The current surge in Covid-19 infections in China is believed to be driven by the BF.7 sub-variant of Omicron that is circulating in that country.
• This isn’t the first time that BF.7 has made news — earlier, it started to replace the variants that were then dominant in the United States and several European countries.

BF.7

• Same as BA.5.2.1.7: a sub-lineage of the Omicron sub-lineage BA.5.
• Has a 4.4x higher neutralization resistance than original D614G variant: antibodies from a vaccinated or infected individual were less likely to destroy BF.7 than the original Wuhan virus that spread worldwide in 2020.
• Not the most resilient sub-variant: a more than 10-fold higher neutralisation resistance in another Omicron sub-variant called BQ.1.

Why high spread in China

• An immune-naïve population : due to lockdown and strict isolation.
• China is now experiencing the typical Omicron surge: that other countries have already witnessed.
• China’s vaccination drive: China’s vaccines were developed against the original variant of the coronavirus which has mutated many times since 2020.