A Facebook post says: “So let me get this straight. The Indian variant has travelled over 4500 miles to get to the UK, yet it hasn’t affected any of the countries in between?” This is not accurate.
The B1.617 lineage (which is sometimes called the ‘Indian variant’) includes a number of different, but closely related, variants. In the UK so far, we have seen B1.617.1, B1.617.2 and B1.617.3. One of these, B1.617.2, has been made a variant of concern due to its increasing rates, and concerns around increased transmissibility. The other two, B1.617.1 and B1.617.3 are currently still variants of interest.
A variant of interest is a variant that could have concerning properties with regard to transmission, ability to evade the immune system or vaccines, or ability to make people more unwell than previous variants. Following further risk assessment by an expert committee, they may then be designated a variant of concern.
It is not clear where the idea that other countries between India and the UK haven’t been affected has come from, and it is not true.
Many other countries have also sequenced cases of the B1.617 variants, including countries across Asia, South East Asia, Australia, the Middle East, Europe, Africa, North America, South America, Central America and the Caribbean. The UK, however, has sequenced the highest number of cases.
For variants to be detected and recorded, they have to be sequenced. There is great variation between countries regarding how much sequencing is performed and so this, in addition to the genuine case numbers, greatly influences the numbers of variants recorded in each country. Because of this, the number of variants (and cases of them) in some countries may be significantly undercounted. This means that, although the UK has sequenced the highest number of cases, it may not necessarily mean there are more cases of this variant in the UK than in other countries.