Here, we demonstrate that the Mu variant is highly resistant to sera from COVID-19 convalescents and BNT162b2-vaccinated individuals. Direct comparison of different SARS-CoV-2 spike proteins revealed that Mu spike is more resistant to serum-mediated neutralization than all other currently recognized variants of interest (VOI) and concern (VOC). This includes the Beta variant (B.1.351) that has been suggested to represent the most resistant variant to convalescent and vaccinated sera to date.
“In this study, we demonstrated that three mutations, the RSYLTPGD246-253N, L452Q and F490S mutations, respectively confer resistance to the vaccine-induced antiviral immunity. Additionally, the T76I and L452Q mutations contribute to enhanced viral infectivity. Our data suggest that there are at least two virological features on the Lambda variant: increasing viral infectivity (by the T76I and L452Q mutations) and exhibiting resistance to antiviral immunity (by the RSYLTPGD246-253N, L452Q and F490S mutations).”
“We also observed that the spike protein of the Lambda variant presented increased infectivity when compared with the spike protein of the Alpha and Gamma variants, both of them with reported increased infectivity and transmissibility. Together, our data show for the first time that mutations present in the spike protein of the Lambda variant confer escape to neutralizing antibodies and increased infectivity.”
“The evidence presented here reinforces the idea that massive vaccination campaigns in countries with high SARS-CoV-2 circulation rates must be accompanied by strict genomic surveillance aimed to rapidly identify new viral isolates carrying spike mutations as well as studies aimed to analyze the impact of these mutations in immune escape and vaccines breakthrough.”
We report the emergence of a novel lineage of SARS-CoV-2 in South America, termed C.37. It presents seven nonsynonymous mutations in the Spike gene (Δ247-253, G75V, T76I, L452Q, F490S, T859N) and a deletion in the ORF1a gene (Δ3675-3677) also found in variants of concern (VOCs) Alpha, Beta, and Gamma. Initially reported in Lima, Peru, in late December 2020, it now accounts for 97% of Peruvian public genomes in April 2021. It is expanding in Chile and Argentina, and there is evidence of onward transmission in Colombia, Ecuador, Mexico, the USA, Germany, and Israel. On June 15, 2021, the World Health Organization designated C.37 as Variant of Interest (VOI) Lambda.
The World Health Organization (WHO) said Wednesday that the coronavirus variant of COVID-19, commonly known as C.37, has been named Lambda. Lambda has been identified in 29 countries, most notably in South America where it is believed to have originated.
First identified in Peru, the Lambda lineage was classified as a global Variant of Interest on Monday due to an “elevated prevalence” in South America, the WHO said in its weekly update.
Lambda has been rampant in Peru where 81 percent of COVID-19 cases since April 2021 were associated with this variant, authorities reported.
In Chile, it was detected in 32 percent of all submitted sequences in the last 60 days, and only outclassed by the Gamma (P.1) variant which was first identified in Brazil. Other countries such as Argentina and Ecuador have also reported elevated prevalence of the new variant.
The WHO reported that the Lambda lineage carries mutations that might increase transmissibility or strengthen the virus’s resistance to antibodies.
However, evidence is too limited for the moment, the Geneva-based organization said, and more studies are required to understand better the Lambda variant.
** Our opinion: At the moment, the Sars-CoV-2 infection numbers in South America seem to be declining after peaking in June 2021. The Delta variant seems to be more of a threat internationally when you compare Latin America infection figures with the UK figures for example **
Lineage prevalence in Peru:
Peru said its Covid-19 death toll is actually almost three times as high as it had officially counted until now. The new figure would rank Peru as one of the world’s hardest-hit countries relative to its population.
The new death toll is estimated at 180,764 through May 22, according to a report released on Monday by cabinet ministers and health officials in Lima, the capital. That is almost triple the official death toll of about 68,000. President Francisco Sagasti is expected to endorse the new death estimate.
The “strong presence” of the C-37 coronavirus variant in Peru since last April has been confirmed, resulting in three variants in total, Health Minister Oscar Ugarte announced on Monday. According to the government official, this new variant could have caused the peak in COVID-19 cases during the second wave.
“The studies carried out by the National Institute of Health (INS) and the Epidemiology Center of the Ministry of Health (Minsa) have confirmed the presence of a new variant in the country: the C-37 […] a strong presence has been observed since April,” he said at a press conference.
C.37: Novel lineage expanding in Peru and Chile, with a convergent deletion in the ORF1a gene (Δ3675-3677) and a novel deletion in the Spike gene (Δ246-252, G75V, T76I, L452Q, F490S, T859N)
Approximately 40% of cases of the new coronavirus in Lima have been due to the P.1 Brazilian variant of this disease, according to a study carried out by the Peruvian National Institute of Health (INS).
This was indicated in a press conference by the Minister of Health, Óscar Ugarte . He added that the advance of this variant that has already passed through Loreto and Huánuco is being determined .
“This INS study is extremely important because it has made it possible to identify, through a sampling throughout Lima, that the main variant that causes COVID-19 today in a percentage of 40% is the Brazilian variant,” he said.
Preliminary results from a study examining the efficacy of the Oxford-AstraZeneca coronavirus vaccine indicate it is significantly effective at preventing severe illness from COVID-19.
Results of the trial, which involved more than 32,000 volunteers, showed two doses of the vaccine administered four weeks apart had an efficacy of 79% at preventing symptoms of COVID-19. In participants aged 65 years and over, vaccine efficacy could be as high as 80%, AstraZeneca announced early Monday. It had an efficacy of 100% at preventing severe disease and hospitalization.
The Peruvian Ministry of Health on Friday received a donation of 60 mechanical and 40 multi-parameter ventilators from the United Kingdom of Great Britain and Northern Ireland. This donation exceeded US$700,000.
The equipment will be destined for various hospitals nationwide where critical and moderate patients affected by COVID-19 are being treated.
Health Minister Oscar Ugarte thanked the UK for this gesture of solidarity.
“We appreciate this donation for the value it has in saving lives. Likewise, I want to emphasize that the collaboration from the United Kingdom to the Peruvian health system is historical and very friendly,” he said.
In turn, Prime Minister Violeta Bermudez expressed gratitude for this act of solidarity.
“These equipment will be put into operation as soon as possible so that the health system can rely on this valuable resource soon,” she stressed.