What scientists know about Lambda variant of COVID-19
MANILA, Philippines — The Department of Health on Sunday announced it has detected the country’s first case of the Lambda variant of COVID-19, alarming Filipinos who are already worried about the rapidly spreading Delta variant.
The case was a 35-year old pregnant woman who tested positive for COVID-19 in July and has since recovered. DOH Undersecretary Maria Rosario Vergeire said the patient was a local case.
The variant, initially known as C.37, was first detected in Peru late last year. According to a mid-June update of the World Health Organization, Lambda had been reported in 29 countries and territories.
WHO also classifies it as a “variant of interest.”
Is Lambda more transmissible than other forms of COVID-19? Does it cause more severe disease? Do vaccines work well against this variant?
Much remains unknown about Lambda and its epidemiological impacts. But here are answers to some questions about the variant, according to medical authorities and studies.
Is it more transmissible?
Lambda is a variant of interest, which means it has genetic changes that are predicted or known to affect virus characteristics such as transmissibility and causes significant community transmission.
In June, WHO said Lambda is associated with “substantive rates of community transmission in multiple countries, with rising prevalence over time concurrent with increased COVID-19 incidence.”
“Lambda carries a number of mutations with suspected phenotypic implications, such as a potential increased transmissibility or protein increased resistance to neutralizing antibodies,” WHO said.
It is important to note that Lambda is a degree lower than the variants of concern, such as Alpha, Beta, Delta and Gamma.
A preliminary study, which has not yet been peer-reviewed, suggests that mutations present in the spike protein of Lambda have increased infectivity. Scientists from the University of Chile said the Lambda’s increased viral infectivity is higher than that of the Alpha and Gamma variants.
“However, there is currently limited evidence on the full extent of the impact associated with these genomic changes, and further robust studies into the phenotypic impacts are needed to better understand the impact on countermeasures and to control the spread,” the UN health agency said.
Are vaccines effective against Lambda?
WHO said further studies are required to validate the continued effectiveness of vaccines against the Lambda variant.
Results of the Chile study—which, again, has yet to be reviewed by other scientists—indicate that the spike protein of the Lambda variant “confers immune escape to neutralizing antibodies elicited by the CoronaVac vaccine.”
The study looked into healthcare workers who received two doses of the vaccine developed by China’s Sinovac Biotech.
A preprint from the New York University Grossman School of Medicine also suggests that Lambda’s spike protein showed a partial resistance to neutralization of antibodies elicited by mRNA vaccines such as those developed by Pfizer and Moderna.
But it concluded that current vaccines will provide protection against Lambda and other variants.
“Both [US and Chile studies] find neutralization by vaccinee sera to be reduced for Lambda compared to viruses from earlier in the pandemic. These are small studies and it is difficult to make any clinical extrapolation from this early data,” Public Health England’s risk assessment read.
Vergeire pointed out that antibodies are not the body's only defense against SARS-CoV-2—the virus that causes COVID-19. T cells may also provide protection.
“Most of the variants of concern that we have right now like Beta and Delta affect the efficacy of vaccines. But our experts also say that aside from the level of antibodies that we see in our vaccinated individuals, we also have cell mediated immunity. These are the T cells, which are not affected by variants and remain our protection—provided by vaccines—against the virus,” Vergeire said partly in Filipino.
“Let's still get vaccinated because vaccines are effective against variants,” she added.
Is it worse than Delta?
Public Health England said “there is no evidence as of yet of a country where it (Lambda) is outcompeting Delta.”
Delta is the “fastest and fittest” form of COVID-19 and is now dominating most of the world.
But for Dr. Rontgene Solante, head of adult infectious diseases unit at San Lazaro Hospital, the country must treat the Lambda variant like the hyper contagious Delta variant.
“We need to treat this something like Delta. We need to enhance our vaccination rollout, protect ourselves and always comply with health protocols,” Solante said in an interview with ABS-CBN News Channel.
DOH also said that active case finding, aggressive contact tracing, and immediate isolation/quarantine can lower the transmission of COVID-19 and its variants.
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