Brazilian coronavirus variant may be more transmissible, evade immunity: Study

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New Delhi, Apr 29 (PTI) The P.1 coronavirus variant, which originated in Brazil, is likely to be more transmissible than other strains of SARS-CoV-2, and might be able to evade immunity gained from previous infection with the virus, according to a modelling study.

The research, published in the journal Science, used data from Manaus city in Brazil to characterise P.1 and its properties, including 184 samples of genetic sequencing data.

Manaus is facing a massive second wave outbreak, with high number of daily deaths and instances of the health care systems collapsing.

The researchers from University of Copenhagen in Denmark and colleagues in Brazil found that genetically speaking P.1 is different from the previous strains of coronavirus.

It has acquired 17 mutations including an important trio of mutations in the spike protein -- K417T, E484K and N501Y, they said.

The spike protein helps the coronavirus to infect the human cells.

'Our epidemiological model indicates that P.1 is likely to be more transmissible than previous strains of coronavirus and likely to be able to evade immunity gained from infection with other strains,' said corresponding author of the study, Samir Bhatt, a researcher at University of Copenhagen.

The researchers noted that P.1 emerged in Manaus around November 2020.

The variant has since spread to several other states in Brazil as well as many other countries around the world, including India.

'It went from not being detectable in our genetic samples to accounting for 87 per cent of the positive samples in just seven weeks,' Bhatt said.

The researchers then used an epidemiological model to estimate how transmissible P.1 seemed to be.

They also estimated signs of P.1 evading immunity gained from previous infection.

'Roughly speaking, our model incorporates many data sources such as mortality counts and genetic sequences and compares two different virus strains to see which one best explains the scenario that unfolded in Manaus,' Bhatt said.

'One was the 'normal coronavirus' and the other was dynamically adjusted using machine learning to best fit the actual events in Brazil,' he said.

This modelling allowed the researchers to conclude that P.1 is likely to be between 1.7 and 2.4 times more transmissible than non-P1-lineages of the coronavirus.

They also conclude that P.1 is likely to be able to evade between 10 and 46 per cent of the immunity gained from infection with non-P.1 coronavirus.

'We have to caution extrapolating these results to be applicable anywhere else in the world. However, our results do underline the fact that more surveillance of the infections and of the different strains of the virus is needed in many countries in order to get the pandemic fully under control,' Bhatt added. PTI SAR SAR