China's is inhaled through the mouth with a nebulizer. India also has one that's a nasal spray. The idea behind both is to not only protect against severe disease but also stop infection + transmission. It's great for children or for anyone that just doesn't prefer a jab

Yep the bivalent (BA.5) booster will fare better against BF.7. The US has inhaled vaccines under development but those haven't gotten that far partly due to funding, research, or political reasons.

BF.7 is a bit more immune evasive + transmissible compared to BA.5 and shows reduced sensitivity to monoclonal antibodies likely due to an amino acid change at R346T.

BF.7 actually refers to the name of the variant where each variant will have a whole host of mutations that define it. That aside, the current epidemiological situation in China results from the dropping of their "zero covid" policy. Due to this alone, there are a couple things happening:

• BF.7 is highly immune evasive, people vaccinated in China (even with 3 doses) are very unlikely to be protected from infection. Vaccination coverage is extremely low in the most vulnerable age groups. ~40% of elderly above age 80 have a 3rd dose, ~70% have 2 doses. This likely increases the amount of deaths reported as BF.7 does not show any noticeable changes in clinical severity compared to other Omicron subvariants. At the current time, it's more likely we're seeing a founder effect where the initial strain to first hit the population will dominate the landscape regardless of how fit the virus is. For example, XBB is way more fit to sweep China but that isn't happening (yet). This leads into my next point:

• We're seeing unprecedented infections in a population that is largely infection naïve. Compared to the rest of world where there is stronger hybrid immunity built up from vaccination + infection induced immunity, China is facing the 1st wave in a population with solely boosted immunity. As seen in the rest of the world, current variants were capable of causing waves every couple months in spite of infection-induced immunity.

• 3 doses (Coronavac) + BF.7 infection also does not provide strong protection from infection against the variants that are currently the most dominant around the world (XBB and BQ.1.1).

On the other hand there are some upsides:

• BF.7 has circulated widely around the world and was detected in many different countries prior to China's current predicament. BF.7 was de-escalated from monitoring in the UK for low growth rates. BF.7 still makes up a sizeable proportion of sequences at the moment (<10% depending on the country) but BQ.1.1, BQ.1.1.10, XBB.1 and XBB.1.5 are now currently the variants to watch.

• China's approval of an inhaled vaccine may help to curb infections. Something the rest of the world should adopt. Though it's unknown how widespread its deployment is and whether it was given to enough people to curb infections (unlikely considering the numbers we're seeing)

That said, there is definitely cause for concern. Globally, sequencing for SARS-CoV-2 has dropped 90% and widespread infections in such a large population (in a short time) could be cause for worry due to the possible emergence of a new variant. Certain countries are in response testing for novel mutations that might pop up from inbound travelers.

For further reading:

on variants and mutations

overview of BF.7

Coronavac vaccine against dominant variants