Amid South Africa’s third wave of Covid-19 thanks to the spread of the Delta variant, concerns have grown around another mutation of the virus which has drawn the attention of global health experts.
The World Health Organisation (WHO) recently added the Lambda variant as its seventh and latest Covid-19 “variant of interest”.
Initially called C.37, Lambda was first detected in Peru in December 2020, where it quickly spread to become the dominant variant.
It has been responsible for more than 80% of cases recorded in that country since April and has been found in 31 countries over the last four weeks. Outside of Peru, its spread is most prevalent among the country’s immediate neighbours in South America.
The good news for South Africa is that the Lamda variant has not yet been detected here.
“We have not detected this particular variant,” the acting executive director of the National Institute for Communicable Diseases, Professor Adrian Puren, recently told SABC News.
“As you know in South Africa we do have a network of laboratories together with the private sector that is constantly monitoring variants that are in circulation and obviously focusing on variants of interest, or [variants] of concern.”
Much of the concern about this variant has been centred around the fact that Peru currently has the highest Covid-19 mortality rate of any country, in relation to the size of its population.
Almost 200,000 people have died from Covid-19 in Peru, which had a population of around 32.5 million in 2019.
However, Professor Tulio De Oliveira of the KwaZulu-Natal Research and Innovation Sequencing Platform (KRISP) has pointed out to eNCA, that many of Peru’s deaths were related to the pre-variant, and that Peru has also recently started counting certain excess natural deaths towards Covid-19 figures.
Most countries only note a death as related to Covid-19 when a person tested positive for the coronavirus that causes it.
Peru’s government has decided to include people who died within 60 days of a positive test, as well as other suspected cases to that figure.
While its mortality rate may be a more true reflection of actual Covid-19 deaths, it makes it difficult to compare with other countries.
The main questions around Lambda are whether it is more transmissible, more likely to cause death, or more resistant to vaccines.
It’s important to note that the variant of interest (VOI) classification differs from the variants of concern (VOC) list, which currently only includes the Alpha, Beta, Delta, and Gamma variants.
According to the WHO, the latter four variants have shown to be associated with one or more of the following changes at a degree of global public health significance:
- Increase in transmissibility or detrimental change in Covid-19 epidemiology
- Increase in virulence or change in clinical disease presentation
- Decrease in effectiveness of public health and social measures or available diagnostics, vaccines, therapeutics
The WHO said Lambda has been associated with substantive rates of community transmission in multiple countries, with rising prevalence over time concurrent with increased COVID-19 incidence.
However, it notes that there is currently limited evidence on the full extent of the impact associated with its genomic changes, and further robust studies into the phenotypic impacts are needed to better understand the impact on countermeasures and to control its spread.
A report from the Financial Times explains that analysis of Lambda has shown it has a unique pattern of seven mutations in the spike protein that the virus uses to infect human cells.
One mutation, in particular, has intrigued scientists.
Called L452Q, it appears similar to the L452R mutation believed to contribute to the high infectiousness of the Delta variant.
Researchers at the University of Chile who studied Lambda’s effect on viral infectivity found that that it was more infectious than the Alpha and Gamma variants and better able to escape the antibodies created by vaccines.
It should be noted, however, that the researchers only tested this against the Chinese Sinovac CoronaVac vaccine, which is not currently being used in South Africa. The study has not yet been peer-reviewed either.
It is therefore still unclear whether this variant is more transmissible or deadlier than those which came before it.
The good news is that multiple local health experts agree that current vaccines are likely to be effective against Lambda, at least to an extent.
De Oliveira said that the variant had a similar neutralisation status as the previous variant which spread through South Africa during the second wave — Beta.
While the efficacy of the vaccines against Beta was less than with pre-variant Covid-19, they were still very effective at preventing hospitalisation and death.
“What we know at the moment is that the vaccines, especially the ones being rolled out in South Africa, the Pfizer and the Johnson & Johnsson vaccines, are likely to be very effective on that variant,” De Oliviera stated.
Dr Richard Lessells of the Africa Centre for Health and Population Studies concurred, and told SABC News that it was important to understand that none of the variants detected so far completely escaped the vaccines.
“If you look at what the vaccines are designed to do, which is prevent severe illness, they’re holding up very well against all these different variants that are emerging,” Lessells said.
“We don’t see big warning signs that this variant would escape the current vaccines.”
There is also no evidence yet that the variant has spread to Africa, with one possible case in Zimbabwe still under investigation.
In the event that it does, early indications are that it won’t be as infectious as the Delta variant.
In the UK, for example, only 8 cases of the new variant were recorded in the week leading up to 30 June, compared to 50,000 cases of Delta.