Lambda COVID variant: All you need to know about the UK coronavirus strain
It’s been a year since the Lambda COVID variant first emerged in Peru. Is the strain still a threat?
Monitoring from around the world shows that instances of the Lambda COVID variant have been declining.
In the last four weeks, there have only been eight new cases globally that were associated with the Lambda strain, according to the GISAID COVID tracking initiative. Of these, six were in Chile, one in Argentina and one in Sint Maarten.
The latest UK Government case data, published 17 September 2021, has confirmed that there have been no new cases of the Lambda variant of interest within the last week.
The variant, also known as C.37, was first detected in Peru, in August 2020. Peru has had no new cases of Lambda in the last month.
However, the WHO and experts from around the world will continue to monitor numbers of the Lambda strain, keeping it on the list of classified variants of interest.
The spread of the strain across Chile in early August was a cause for concern, according to researchers at Kyoto University.
They say that because the proportion of people who have had at least one dose of a coronavirus vaccine in Chile is relatively high, the rise in cases suggested “that the Lambda variant is proficient in escaping from the antiviral immunity elicited by vaccination”.
However, the most common vaccine administered in Chile is CoronaVac, which works differently to the Pfizer, Moderna and AstraZeneca jabs offered in the UK.
Researchers at the NYU Grossman School of Medicine tested the effectiveness of mRNA vaccines, like Pfizer and Moderna, against the Lambda variant.
According to their results – which have yet to be peer-reviewed – there was a “partial resistance to neutralisation”, however this “is not likely to cause a significant loss of protection against infection” in vaccinated individuals.
But their analysis of the spike proteins on the SARS-CoV-2 Lambda variant showed a two-fold increase in infectivity, which scientists say is due to a particular mutation on the virus called the L452Q mutation.
Lambda was classified as a variant of interest at the global level by the World Health Organization (WHO) on 15 June 2021.
As a variant of interest, the WHO considers Lambda to have mutations with established, or suspected, implications for its transmissibility and severity, and has been detected in multiple countries.
Dr Maria Van Kerkhove, the WHO’s technical lead on COVID-19, said that the organisation is tracking the strain to see if it should be classified as a variant of concern. This would happen if the strain “demonstrated properties of increased transmissibility”, or “if it has increased severity,” she said.
The Lambda variant will only be designated a variant of concern if it is deemed to either: increase the transmissibility of the virus; show a detrimental change in its epidemiology; increase in virulence; change the disease presentation/symptoms; or shows decrease in the effectiveness of testing, treatment, and prevention measures such as vaccinations.
How many cases of the Lambda variant have been detected in the UK?
As of 17 September 2021, there have been nine confirmed cases of the C.37 variant in the UK. Eight were found in England, one in Northern Ireland.
The majority of these are linked to overseas travel, according to a PHE spokesperson. There have been no cases reported in the UK within the last four weeks.
“There is currently limited evidence available about this variant,” Dr Alicia Demirjian, COVID Incident Director at Public Health England (PHE), told BBC Science Focus magazine.
“PHE, together with academic partners, is undertaking investigations to better understand the impact of the mutations on the behaviour of the virus. We are closely monitoring the situation in those countries where this variant is prevalent and where cases are detected in the UK, we are testing contacts and will undertake targeted case finding if required.”
A report by PHE on the variants of concern or under investigation in the UK shows that the Delta variant continues to be the prominent strain in the UK. In the week leading up to 25 August 2021, there were 49,960 new cases of the Delta variant.
Will vaccines still work against the Lambda variant?
In a pre-print paper that has not yet been peer-reviewed, researchers found that mRNA vaccines are effective against the Lambda variant. Both the Pfizer and the Moderna coronavirus vaccines used in the UK are mRNA jabs, meaning they contain genetic material that instructs the body’s cells to produce coronavirus spikes, which then provokes an immune response.
The results of this paper suggest that vaccines in current use will remain protective against the Lambda variant.
However, in another pre-print paper, Lambda was found to have mutations that had “the ability to escape from neutralising antibodies elicited by CoronaVac”. CoronaVac is a vaccine being used in several Asian countries, and works by administering an inactive version of the SARS-CoV-2 virus, which then triggers an immune response.
Researchers have stressed that further studies are required to validate the effectiveness of vaccines.
Is the Lambda variant more transmissible?
While it is not known yet whether this new variant is more transmissible, scientists say the Lambda strain does carry a number of mutations that could potentially lead to increased transmissibility or increased resistance to the antibodies provided by a COVID-19 vaccination or prior exposure to the virus.
One of the mutations identified in the Lambda strain is referred to by scientists as T859N, and has been found in the so-called ‘Iota’ variant currently spreading in New York City.
Another mutation, at L452Q, is reported as being “similar to the mutation reported in the Delta and Epsilon variants” which is believed to affect its susceptibility to antibodies.
However, it’s important to note that research on this specific variant is all in early stages.
As there is currently little evidence to show exactly how the Lambda variant is different to the other strains, scientists say that further, more robust studies, are needed before we can understand the full extent of the strain’s effect.
What are the symptoms of the Lambda variant?
At present, there is nothing to suggest that the symptoms of infection with the new C.37, or Lambda, variant are different to other coronavirus strains.
The main symptoms of COVID-19, according to the NHS, are:
- a high temperature – this means you feel hot to touch on your chest or back (you do not need to measure your temperature)
- a new, continuous cough – this means coughing a lot for more than an hour, or three or more coughing episodes in 24 hours (if you usually have a cough, it may be worse than usual)
- a loss or change to your sense of smell or taste – this means you’ve noticed you cannot smell or taste anything, or things smell or taste different to normal
The NHS say that most people who have symptoms of COVID-19 will have at least one of the above.
What other variants of concern have been identified in the UK?
It is common for viruses to mutate when they replicate. Few of these small, genetic changes lead to a more harmful infection.
As of 17 September 2021, there are five strains considered to be ‘of concern’ by PHE, including the Delta and Alpha variants.
The PHE are monitoring a total of 16 variants.