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Scientists studying omicron in South Africa see rise in covid-19 reinfections

Scientists studying omicron in South Africa see rise in covid-19 reinfections

Scientists in South Africa tracking the spread of Omicron say they are seeing a rise in coronavirus reinfections in people who had recovered from Covid-19, suggesting previous infection provides less protection against the new variant than with earlier versions. “Previous infection used to protect against Delta, and now with Omicron it doesn’t seem to be the case, Professor Anne Von Gottberg from the National Institute for Communicable Diseases in Johannesburg said Thursday. However, she said a past infection should still offer protection against severe disease, hospitalization and death. Vaccines have also fended off the worst of the disease caused by variants with some similar characteristics to Omicron, giving reasons for hope that they will do so in the case of the new variant. The variant has been detected in more than 30 countries world-wide, with most cases in southern Africa from where many of the infected people identified elsewhere have traveled. In a minority of countries, such as the U.K., Belgium and Germany, Omicron has been identified in people who aren’t known to have had contact with travelers. In Norway, more than 50 people who attended an event in Oslo have tested positive for Covid-19 in what authorities in Norway said on Thursday was a suspected outbreak of the new variant. At least one of those people is a confirmed Omicron case, the Oslo municipality said in a statement, citing genome sequencing from that patient. The remaining roughly 50 people who tested positive for Covid-19 are being investigated to see whether they have the variant, the statement added. It wasn’t yet clear how severe or mild the cases were. All of the participants were asked to take Covid-19 tests before attending and the group was mostly vaccinated, the statement said. More than 70% of Norwegians are vaccinated. Participants came from around the country to attend the event in the capital, it added. Contact-tracing teams are seeking others who may have been exposed. Like other European countries, Norway has been seeing a spike of cases largely attributed to the Delta variant, averaging more than 2,000 cases daily over the past week. The country of more than five million people is averaging about six deaths daily. With just 24% of the population fully vaccinated in South Africa, a country that has suffered several waves of the pandemic, natural immunity from infection has been viewed as an important shield against the virus. The country’s biggest private health insurer estimates that, based on the large number of excess deaths in South Africa, around 70% of the country’s 60 million people have already had Covid-19. South Africa uses vaccines developed by Pfizer Inc. and BioNTech SE, and Johnson & Johnson, having suspended the use of the vaccine developed by AstraZeneca PLC and the University of Oxford due to its limited effectiveness against the earlier Beta variant. Since the emergence of Omicron, which carries more than 50 mutations compared with the original version that emerged in 2019 in China, scientists, policy makers and governments have been desperately seeking more information on how it spreads as well as how it responds to vaccines, treatments and immunity from previous infections. The World Health Organization declared Omicron a variant of concern on Nov. 26, based on the rapid spread in South Africa and virus mutations that suggest it could spread faster and better evade antibodies generated to fight the infection. The WHO also cited the risk of reinfection as one of the reasons for its concern. Newly reported cases of Covid-19 almost doubled Wednesday in South Africa as the U.S. reported its first case of the strain in someone who had returned from a trip to the country. The NICD said the number of reported cases in South Africa rose from 4,373 on Tuesday to 8,561 on Wednesday. This compares with 1,275 cases on the previous Wednesday and 116 cases on Nov. 8, the date of the earliest case of Omicron so far detected. “Most of them are in the epicenter of our current beginning of the fourth wave, said Prof. Von Gottberg, referring to Gauteng province, home to both Pretoria and the economic capital, Johannesburg. “The numbers are increasing very, very quickly. Around three in four genetically sequenced samples in the country in November were Omicron and the variant looks like it is predominating in South Africa, she said. Authorities elsewhere, many still tackling a wave of the earlier Delta variant, are expecting Omicron to pose more challenges to their pandemic defenses. Jean-François Delfraissy, who leads the scientific board advising French authorities about the pandemic, said the Omicron variant will become common in France and Europe by around the end of January. He told French television that he expects it to progressively take over from the Delta variant. Prof. Von Gottberg said it was too early to say at what rate reinfections were happening in South Africa but added that it was worrying that they were occurring more often than with previous variants. A person is deemed to have been reinfected if they return a positive test more than 90 days after first testing positive for the virus. “In our population…where many people have had previous infection, we believe that that previous infection doesn’t provide them with protection from infection due to Omicron, Prof. Von Gottberg said. “However, hopefully it provides them with protection against severe disease, hospital admissions and death. This story has been published from a wire agency feed without modifications to the text Download.

science 2021-12-03 Livemint