Since variant B.1.1.7 of the new coronavirus appeared in the UK, researchers have focused on determining whether the new strain would be more virulent or more deadly than the original virus. A study by the London School of Hygiene and Tropical Medicine (LSHTM) ended the doubt: yes, the variant is more contagious and more lethal.
The study was conducted by the LSHTM Center for Mathematical Modeling of Infectious Diseases (CMMID), which analyzed 150,000 blood samples from covid-19 patients across the UK and concluded that the so-called Kent variant is between 43% and 90% % more contagious.
The time when SARS-CoV-2 infects a cell.Source: IOC / Fiocruz / Débora F. Barreto-Vieira / Disclosure
Published in the magazine Sciencand, the study found no evidence that the B.1.1.7 strain is responsible for more severe cases of the disease; however, it is associated with a 58% increase in the risk of death.
Also called VOC 202012/01 (VOC meaning variant of concern, or variant of concern), it has spread, according to the World Health Organization (WHO), in 60 countries – in Brazil, 20 cases have already been identified in eight states.
More vaccine and less street
“All the updates we’ve made are compatible with the hypothesis that B.1.1.7 is more lethal. Without strict control measures, including the partial closure of educational institutions and a great acceleration of vaccination campaigns, the number of hospitalizations and deaths by covid-19 in England in 2021 will be greater than in 2020 ”, said biostatistics and co-author Karla Díaz Ordaz.
Modeling the progress of the disease showed that the risk of a man over 60 years of age after testing positive for covid-19 would jump from 0.6% (original strain) to 0.9% (VOC 202012/01) – a 50% increase. In people over 85, the percentages jump from 13% to 20% in women, and from 17% to 26% in men.
After the increase in cases, the government asked the British to stay home, protect the hospital system and save lives.Source: In Pictures / Mike Kemp / Reproduction
According to the study’s leader, infectious disease specialist Nicholas Davies, “42,000 people died of covid-19 in England in the first two months of 2021, the same number of deaths between March and October 2020. I am sure that a large part of these deaths would have avoided if variant B.1.1.7 ”did not exist.
Two strains in one
The virulence of the Kent variant worries about the possibility of it combining with other strains – which is already happening. A study published by Brazilian researchers from the National Scientific Computing and Molecular Microbiology laboratories at Feevale University identified at least two cases of patients who simultaneously contracted two variants of SARS-CoV-2.
“The detection of multiple variants in a person can be the result of co-infection or the generation of mutations within the patient. In the Brazilian study, the strains identified corresponded to different strains previously detected in the population, implying co-infection by two variants ”, he explained in an article for the website The Conversation molecular biologist Maitreyi Shivkumar, from Montfort University.
Doctors assist a patient with covid-19 in serious condition in the ICU of a hospital in Porto Alegre.Source: Reuters / Diego Vara / Reproduction
According to her, the two cases of co-infection “raised the concern that SARS-CoV-2 could incorporate new mutations even more quickly. This is because, when two viruses of different strains infect the same cell, they can exchange large parts of their genomes with each other and create completely new sequences ”.
Viral rearrangement, however, does not happen if strains replicate in different parts of the body. According to Shivkumar “the evidence so far does not suggest that infection with more than one variant leads to more serious illnesses. And, although possible, very few cases of co-infection have been reported ”.