Expert comment - new Brazilian variant of COVID-19
"The Brazilian variant has 12 mutations in the spike gene which is the part of the virus that is important for its ability to infect our cells. The spike is also a major target for the protective immune response and forms the basis for most of the vaccines including those approved for use in the UK.
"One of the changes in the spike from the Brazilian variant is identical to a mutation (N501Y) in the Kent (UK) variant. The South African variant also has the N501Y mutation along with another change that is also found in the Brazil variant (E484K).
"The N501Y mutation is very likely to increase the strength of binding of SARS-CoV-2 to the ACE receptor – hence the viruses with this change are more sticky for human cells and that’s why they are more infectious. The E484K change appears to provide some escape from immune recognition – it prevents virus infection from being blocked by certain monoclonal antibodies. There is no indication that any of these virus variants are associated with more severe disease.
"We don’t know what this will mean for the overall effectiveness of vaccines. But it is very unlikely that any of these changes will completely abolish vaccine efficacy. The antibody response is very broad producing many different antibodies to different parts of the spike protein. So a few changes won’t make much of a difference. However, the Brazil variant has accumulated more mutations in the spike and this could reduce vaccine efficacy. We need to carefully monitor immune responses in individuals infected with these variants.
Professor Lawrence S. Young, Virologist and Professor of Molecular Oncology, Warwick Medical School
15 January 2021
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