menB outbreak in Kent -- first genome
Previous posts on menB:
UKHSA have sequenced one of the isolates from the outbreak, which is on PubMLST (190637). This is excellent and UKHSA have done a great job sequencing this strain so quickly, and releasing the genome and provisional analysis so quickly.
UKHSA have said that one the outbreak isolates is sequence type 485 and clonal complex ST-41/44. These MLST designations are low resolution molecular fingerprints that don’t tell us that much on their own. UKHSA have shown previously that this strain has probably been circulating since 2010, but increasing in frequency since then. Comparison among more genomes from the outbreak, as they become available, will be more powerful.
I think the key question to answer now from the genome is whether we can find anything that suggests this strain is more invasive. If it’s not, should the UK consider a catch-up campaign in teenagers, as we might expect more outbreaks elsewhere? But it’s going to be hard to disprove this (i.e. show definitively that the genomes are not more invasive).
Alternatively, if we see from other isolates they are not a single outbreak, this would be pretty good evidence there’s nothing special about the strain transmitted in Kent.
Some further genome analysis
Not vaccine escape
Running MenDeVar we can check for overlap with the four proteins in the 4CMenB/Bexsero vaccine. fHBP is an exact match, so the vaccine should work well. NadA appears to be missing, but this should not affect vaccine efficacy, nor does it appear to be a recent genetic event (relatives from 2020 also have it missing). This is actually automated on PubMLST which is very nice.
Evolution and variation
We’ve begun to run some analysis compared to similar isolates to see if there’s anything unusual in the outbreak genome. This is running now, and I hope to be able to post some more findings next week.