Variants of viruses considered more deadly, more contagious; some may thwart vaccines

(Reuters) – The following is a summary of some of the latest scientific studies on the new coronavirus and efforts to find treatments and vaccines for COVID-19, the disease caused by the virus.

Multiple variants may “escape” vaccines

Antibodies induced by the Moderna Inc and Pfizer Inc / BioNTech SE vaccines are dramatically less effective in neutralizing some of the most worrying variants of the coronavirus, a new study suggests. The researchers obtained blood samples from 99 individuals who received one or two doses of any of the vaccines and tested their vaccine-induced antibodies against replicates of viruses designed to mimic 10 variants in global circulation. Five of the 10 variants were “highly resistant to neutralization”, even when the volunteers received both doses of the vaccines, the researchers reported on Friday at Cell. All five highly resistant variants had mutations at the peak on the virus surface – known as K417N / T, E484K and N501Y – that characterize one rampant variant in South Africa and two variants spreading rapidly in Brazil. Following previous studies, the proportion of neutralizing antibodies has dropped 5 to 6 times in relation to the variants discovered in Brazil. Against the variant discovered in South Africa, neutralization fell 20 to 44 times. A variant now circulating in New York has the E484K mutation. “While studies of the New York variant are ongoing, our findings suggest that similar variants that harbor the E484K may be more difficult to neutralize by antibodies induced by the vaccine,” said study leader Alejandro Balazs of Harvard University and the Massachusetts General Hospital. “Despite our results,” he added, “it is important to consider that vaccines enhance other types of immune responses that can protect against the development of serious illnesses.” (bit.ly/3bWB1Ko)

Variant identified in the UK is deadliest

The coronavirus variant first identified in the UK, known as B.1.1.7, is more deadly than other variants circulating there, a new study appears to confirm. The researchers analyzed data from 184,786 people in England diagnosed with COVID-19 between mid-November and mid-January, including 867 who died. For every three people who died within four weeks after being infected with another variant, about five died after being infected with B.1.1.7, according to an article published in medRxiv before peer review. Overall, the risk of death with B.1.1.7 was 67% higher than the risk with other variants in England, the authors said. As with previous variants, patients’ risk of death increased with age, male gender and pre-existing medical conditions. B.1.1.7 is now prevalent across Europe and is expected to become prevalent in the United States. “Crucially,” the researchers wrote, “the emerging data suggests that vaccines currently approved for SARS-CoV-2 are effective against B.1.1.7.” (bit.ly/3r2vpCE)

Variant identified in Brazil is doubly infectious

Between November and January, in Manaus, Brazil, the frequency of COVID-19 cases involving the coronavirus P.1 variant increased from nonexistent to 73%, and the number of infections quadrupled compared to what the city experienced in the first wave of the pandemic, according to a report published in medRxiv before the peer review. The greater infectivity of the P.1 variant probably contributed to this, suggests the report. Based on data from the national health surveillance, the authors estimate that the P.1 variant is about 2.5 times more transmissible than the previous variants that circulated in Manaus. The spread of P.1 occurred despite the fact that 68% of the city’s population had already been infected with the original coronavirus strain, the researchers noted. In his analysis, the risk of reinfection with P.1 was low. The variant’s ability to cause serious illness, or its pathogenicity, remains unclear. “The P.1 variant has already been detected in at least 25 countries,” said the authors. “This requires urgent studies … of the P.1 variant, since greater transmissibility and pathogenicity can lead to the collapse of even well-prepared health systems.” (bit.ly/38MGykw)

To avoid infection, the new CPR technique increases the distance

To avoid coronavirus infection during cardiopulmonary resuscitation (CPR), medical professionals can increase the distance from the patient by doing chest compressions using the bare heel of the foot – known as leg-heel compression – instead of his hands, suggests a new study . The researchers asked 20 medical professionals to perform standard manual chest compression followed by leg-heel chest compression after brief instruction on a mannequin. There was no difference in any of the measured variables, including the correct positioning of the heel for compression purposes, the correct depth of chest compression and the compression rate. The study found that the potential spread of droplets from the patient’s breath to the person performing CPR would likely be minimized with leg-heel compression. “In special circumstances such as the COVID-19 pandemic, leg-heel chest compression can be an effective alternative … compared to manual chest compression, while significantly increasing the distance to the patient,” concluded the researchers. in an article published on medRiv on Monday before the peer review. (bit.ly/3ltWgX4)

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