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Variants fuel COVID-19 surge, but scientists voice optimism for vaccines

By lockdown_exit - 16th Apr 2021, 12:00 am - That was the week that was
  • COVID-19 cases are surging across the world, fuelled by highly contagious variants of the coronavirus that are popping up far from where they were first detected. The spread of these variants, scientists say, highlights how tiny, random changes in the virus's genetic code threaten to undo progress in beating back a global pandemic that has killed at least three million people. Concerning variants are now spreading in the U.S. and Canada, Europe and Latin America.
  • Scientists say variants can be brought under control with now-familiar public health measures such as mask wearing and social distancing, despite evidence that some strains might evade the immune response triggered by vaccination or a past infection.
  • In the UK, for instance, where the variant B.1.1.7 drove a deadly outbreak during the winter, new cases have slowed to a trickle after a strict lockdown and rapid vaccination drive.
  • Scientists are also hopeful that the current crop of vaccines will at least limit the numbers of people falling gravely ill and dying of COVID-19, even if the variants weaken the vaccines' effectiveness at preventing infection. Vaccine makers are already testing new versions of their shots that are being retuned to attack these new variants.
  • Progress, though, depends on bringing the volume of COVID-19 cases under control, both to save lives and to limit the virus's opportunities to alight upon yet more advantageous mutations that could propel future waves of infection.
  • 'The chance of winning the lottery is very small - until you buy all 65 million lottery tickets,' said David Bauer, who leads a group at the Francis Crick Institute in London, studying how coronavirus mutations affect transmissability and disease severity. 'This is why you have virologists saying that what we really need is to get the infection rate down.'
  • Much of Latin America has faced an aggressive variant known as P.1, which emerged in the city of Manaus in Brazil's Amazon region last year. This variant has now been detected in at least 36 countries and in 22 U.S. states. In Brazil, where about 130 people are dying every hour from COVID-19, P.1 has become the dominant strain. A study this month shows P.1 to be responsible for more than 90% of the new infections in Sao Paulo, the biggest city in the southern hemisphere.
  • In Canada, the Pacific Coast province of British Columbia has become one of the biggest P.1 hotspots outside of Brazil, forcing local authorities to prohibit dining and religious services until at least April 19 and to close ski resorts north of Vancouver. Canada is also plagued by the B.1.1.7 variant, which has now spread from the UK to 114 countries and is the dominant variant in the U.S. and in much of Europe.
  • 'We're already in a situation where it's no longer the vaccines versus the variants. It's the variants versus ICU capacity,' said Amit Arya, a palliative care physician in the great Toronto area and professor at McMaster University in Hamilton Ontario.
  • In Spain, health authorities have said this variant was responsible for between 64% and 99% of new infections detected in 17 Spanish regions last week, while health authorities in Italy said it late March the UK variant represented 87% of all new cases there.
  • A third variant troubling scientists is B.1.351, which was first detected in South Africa last year. It has spread quickly across the continent's most developed economy and nearby countries including Zimbabwe, Mozambique and Zambia. B.1.351 has since been detected in almost 70 countries including the U.S., though it has not yet become a major source of infections outside Southern Africa.
  • Doctors fret the new variants might lead to more serious disease or possibly increase the risk of death in someone infected. Brazilian clinicians have said they suspect P.1 to be more lethal, noting a rise in younger and otherwise healthier patients being admitted to ICUs. But, so far, studies into the mortality risks associated with each variant have been inconclusive on each variant and its risk potential.
  • Another question mark hangs over how well the vaccines being rolled out across the world will work in places where the variants are circulating and dominant, and if these variants will be able to seed new outbreaks even in places where vaccination is widespread. To date, multiple lab studies worldwide paint a broad picture of vaccines working adequately against the UK and Brazilian variants but a little less so against the South African one.
  • Scientists say these studies do not necessarily tell the whole story, as the immune responses generated by a vaccine in the body are broader and deeper than those that can be observed easily in a lab. However 'even if existing vaccines aren't as effective at stemming infection with new variants as they are against older strains, they should probably work well enough to stop people from getting severely ill,' said David Matthews, a virologist at the University of Bristol. 
  • Vaccine producers are working on shots that more precisely target these variants and can be distributed as booster shots if needed. Ewan Harrison, a microbiologist at the Wellcome Sanger Institute said 'The vaccine technology is very amenable to changing things quickly. If I was to really put my money where my mouth was, I would say in future years at-risk populations will be having dual flu and COVID-19 booster shot vaccines.'
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