![]() While some news reports have described these new versions of the Covid-19 virus as ‘strains’, it is more accurate to describe them as ‘variants’, says Dr Volz. Both have mutations that allow them to reinfect people who should have immunity after a previous infection or vaccination. These would become known as B1.351 and P1 respectively. Shortly after B117 was detected, another version of the virus with a couple of similar mutations - but also some important distinct ones - was spotted spreading in South Africa and then another was found to be spreading in Brazil. These are variants of SARs-CoV-2, not new strains. ![]() ‘We weren’t expecting B117 to pop up with such a big step change in its transmissibility.' ‘(The) appearance of the new variants were a bit surprising,’ said Dr Volz. This new version of the virus had accumulated 17 separate mutations in a very short period of time and increased the speed with which it spread. The first of these to be detected was the B117 variant identified in samples taken in Kent, south east England, in December 2020. These were new variants showing not just a single change to the spike protein, but multiple important mutations. What had taken place in the virus’s genome had made it evolutionarily fitter than the earlier form of SARS-CoV-2.Ī few months later, the Covid-19 virus underwent even more dramatic changes that are having an ongoing effect on the course of the pandemic. When this version of the virus was noticed in March 2020, 'it was already spreading rapidly around the world,’ he added.īy June, it had become the dominant variant of the virus in the pandemic. ‘We don’t know where this first arose, but it seems there were multiple occurrences of it in China and Europe,’ said Dr Volz. The change also seems to have led the virus to infect larger numbers of younger people than it had previously. ![]() Occasionally, one of these genetic errors can lead to a change that is advantageous to the virus, such as enabling it to get into cells more easily, producing more copies of itself or allowing it to evade the immune response of people it infects.Įarly in the pandemic, one such mutation caused the Covid-19 virus to become more transmissible by increasing how much virus was produced by people it infected, according to research by Dr Volz and his colleagues. ‘The virus is constantly evolving, so we expect to see an accumulation of changes over time,’ said Dr Erik Volz, an epidemiologist who studies the evolution of infectious diseases at Imperial College London in the UK. Most of the viruses with mutations die out, but some go onto infect other cells in the body and eventually other people. Every so often the genetic material the virus carries is copied incorrectly, producing what is known as a mutation. ![]() Whenever the Covid-19 virus infects someone, it hijacks the biological machinery of their cells to create copies of itself. The virus is always changing but occasionally makes an evolutionary leap.Here are five things to know about the new Covid-19 variants:
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