The Delta variant, which was first detected in Chile just two months ago, is now found in 61% of all genome samples. The MU variant, which was rising rapidly until just two weeks ago, appears to have been halted by the surge of Delta cases.
“Delta, since it was detected as a community circulation in the week of July 26, began its participation in the sequencing with 3% of the total positive samples analyzed. The following week it already occupied 6%, then 10% and 22% for EW 33. Since then, it has risen to 29% of the total in epidemiological week (EW) 34 (last August) when 373 samples were sequenced ; 40% in EW 35 with a total analysis of 473 and 61% in EW 36 but with only 71 samples sequenced.
For these same weeks, the Gamma variant of the virus, which for months dominated the infections, has continued to decline. For EW 34, 31% of the total samples were registered; 26% in EW 35 and barely 18% in EW 36.
The Mu variant detected for the first time in Colombia, like Delta, is also on the rise. From 18% in week 33, it went to 30 and 32% in the weeks that follow; while the Andean variant or Lambda continues to decline with 16% in SE, 8% in SE 34 and 2% in SE 35. For EW 36, it does not register presence, although there are still samples to be entered in that week.”
Chile has 77% of its population fully vaccinated:
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.
The new Mu variant, B.1.621, detected for the first time in Colombia, surpasses Lambda and Delta and is already ranked as the second with the highest circulation in Chile. According to the latest epidemiological report from the Public Health Institute (ISP), although Gamma continues to be the most frequent variant with 41%, of the sequenced samples, Mu, with 29%, surpassed Delta (18%) and Lambda (11 %).
In less than a week, the Mu variant detected for the first time in Colombia , has been gaining space at the community level and has doubled its presence in the sequencing of positive samples carried out in the country , according to the latest report of virus variants published today by the Institute of Public Health of Chile (ISP).
LaTercera.com report (in Spanish)
Above, the latest sars-CoV-2 variant chart for Chile.
Below, the same chart just two weeks ago:
A study conducted in Hong Kong on more than a thousand patients shows that the Coronavac vaccine, developed by the Chinese laboratory Sinovac, causes the production of ten times less antibodies than the vaccine developed by BioNTech and produced by Pfizer.
This comparison between the two vaccines available in Hong Kong was conducted by researchers at the University of Hong Kong on 1,442 health workers who received two doses of these vaccines.
Published in the medical journal The Lancet Microbe on July 15, the article specifies that the quantity of antibodies is not sufficient to assess the level of immunity conferred by a vaccine, but that “the differences in the concentrations of neutralizing antibodies identified in our study could result in substantial differences in vaccine efficacy ”. The researchers add that patients who received Coronavac show similar antibody levels to patients who contracted Covid-19 and are cured.
“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:
As of the early hours of this Saturday, 12th June 2021, Santiago de Chile has once again entered quarantine. The entire region begins with the mobility restriction measure when 57.8% of the country’s target population has completed their covid-19 vaccination schedule, but ICUs are on the brink of collapse.
According to the latest figures provided by the Undersecretary of Health, Paula Daza, the occupation of critical beds reaches 96% nationwide. But the vast majority of seriously ill patients are not immunized and there is a worrying decrease in the age of patients admitted to critical beds. Patients under 50 years of age in ICUs have tripled compared to the worst moment of last year, according to ICOVID, an initiative led by the University of Chile, the Pontificia Universidad Católica de Chile and the University of Concepción based on official data . The deaths reach 38,685, between confirmed and suspected.
El Pais report (in Spanish)
Lineage chart courtesy of Outbreak.info
Daily cases chart courtesy of OurworldinData.org
“Instead of following evolving evidence, the [Swedish] FHM has doubled down and defended its approach without reconsidering the assumptions on which the failed national approach is based. It has downplayed the roles of asymptomatic spread, aerosol transmission, children as potential source of infection, and the use of face masks. It has maintained an approach that mainly builds on recommendations to take voluntary actions, guided (in our view) more by public opinion than by sound public health policy. “
If a picture is worth a thousand words, how much is one simple graph like this worth?
China’s top disease control official says the effectiveness of Chinese vaccines is low and the government is considering mixing them to give them a boost. Chinese vaccines “don’t have very high protection rates,” said the director of the China Centers for Disease Control, Gao Fu, at a conference Saturday in the southwestern city of Chengdu.
Beijing has distributed hundreds of millions of doses in other countries while also trying to promote doubt about the effectiveness of Western vaccines.
“It’s now under formal consideration whether we should use different vaccines from different technical lines for the immunization process,” Gao said.
The effectiveness rate of a coronavirus vaccine from Sinovac, a Chinese developer, at preventing symptomatic infections has been found to be as low as 50.4% by researchers in Brazil. By comparison, the vaccine made by Pfizer has been found to be 97% effective.
The study by the University of Chile found inoculation to be 56.5 percent effective in protecting recipients two weeks after the second dose, and 27.7 percent effective within the first two weeks.
But for a single dose, efficacy in the 28 days between the first and second dose was only three percent — on par with the margin of error in such studies, it said.
Chile’s big coronavirus vaccine bet on China’s Sinovac shots. Chile hopes to reach herd immunity by the middle of the year and is nearly halfway to vaccinating its entire population. The Chinese made Sinovac vaccine has played a major part in the campaign, despite not releasing final phase data.
“This Monday the most restrictive measures to stop contagions begin to take effect: curfew at 9 p.m. and border closures
On this day, the borders will be closed for at least 30 days, and the curfew will begin at 9:00 p.m., extending until 5 a.m. There will also be new limitations to essential activities, where by essential good will be understood those essential goods for subsistence, telework, real estate security, distance education.“