Lambda variant: What is the new strain of Covid detected in the UK?

The Lambda variant - known to scientists as C.37 - was first identified in Peru and has been detected in samples dating back to as early as December 2020.

Since then it has become the dominant variant in the South American country, where it accounts for more than 80 per cent of new infections.

It has now been detected in at least 26 countries, including the UK. So should we be concerned?

A Variant of Interest

The World Health Organisation designated the Lambda variant as a variant of interest on 14 June.

Nine days later Public Health England announced it was a "variant under investigation" based on a number of mutations to the spike protein which enables the virus to attach to human cells.

Of most concern to scientists is its "potential increased transmissibility or possible increased resistance to neutralising antibodies" - meaning it could spread faster and be more resistant to vaccines or antibody treatments.

However, PHE said "there is currently no evidence that this variant causes more severe disease or renders the vaccines currently deployed any less effective."

What is the latest research?

A new study - which has not yet been reviewed by other scientists and is based on tests on samples from healthcare workers in Chile - suggests that the Lambda variant is more infectious than both the Alpha (UK) or the Gamma (Brazil) variants.

It also suggests that the Lambda variant has a higher "immune escape" compared to the Alpha or Gamma variants in relation to antibodies produced in patients who have received China’s CoronaVac (Sinovac) vaccine. (The preprint, published on 1 July, did not look at other vaccines).

How widespread is the Lambda variant in the UK?

A total of eight cases have been detected in the UK, as of the latest update on 2 July - although this is likely to be an underestimate.

In its initial report on 25 June, PHE gave further details of the first six cases identified by DNA sequencing or genotyping.

Four cases were from London, one was from the South West and one was from the West Midlands. All six were linked to overseas travel.

None of the cases has resulted in deaths within 28 days of a positive test.

By comparison, 275,233 cases of the Alpha (UK) variant have been confirmed in the UK (although the total is likely to be much higher as it was the dominant strain during the second wave over the winter), and a total of 161,981 cases of the Delta variant which was first identified in India have been reported.

"Cases are managed in line with the approach for emerging variants with review of contact tracing, additional data collection, testing of identified contacts, and consideration of targeted case finding as required where there is evidence of community transmission," said PHE.