Manaus variant ‘can cause reinfection in up to 61pc of people’

LONDON: The Manaus variant of coronavirus detected in the UK could cause reinfection for between 25 per cent and 61 per cent of people who have previously had Covid, a new study suggests.

Research on the P1 variant among people living in the Brazilian city of Manaus found potentially high levels of reinfection, and that the variant was more transmissible than the original pandemic strain.

British experts have cautioned that the study cannot be used to predict what may happen in the UK, and say it does not suggest that vaccines will not work against the variant. To date, six cases of the Manaus variant have been found in England and Scotland, with experts still hunting for one of the six who tested positive.

According to the new study, from organisations including Imperial College London, Oxford University and the University of Sao Paulo, blood studies suggest more than 67 per cent of people in Manaus may have had Covid by October 2020.

There was surprise then when the city suffered another huge wave of coronavirus at the start of this year, so experts sought to find out why.

They found that the proportion of Covid cases that were the P1 variant grew from zero to 87 per cent in about eight weeks.

P1 was found to be 1.4 to 2.2 times more transmissible than other variants in Manaus, and was found to evade 25 per cent to 61 per cent of protective immunity from previous infection. Dr Nuno Faria, reader in viral evolution at Imperial, told a briefing: “If 100 people were infected in Manaus last year, somewhere between 25 and 61 of them are susceptible to reinfection with P1.”

He said more work was needed on patterns that might occur in other countries, adding: “We know that vaccines are effective and they can protect us from infection and from disease and death.

“This is a period to be optimistic about the future. The more we know about the virus, the better we’re able to protect against it and I think there’s no concluding evidence to suggest at this point that the current vaccines won’t work against P1.” Sharon Peacock, executive director and chairwoman of the Covid-19 Genomics UK (COG-UK) consortium, and professor of public health and microbiology at the University of Cambridge, said P1 had been found in 25 countries to date.

But she said the current study could not be used to speculate on the effectiveness of vaccines or how things will “pan out in other countries including the UK”.

How the findings, which have yet to be peer-reviewed, “relate to United Kingdom is yet to be determined”, she added.

The current dominant strain in the UK is the Kent variant and “we should be optimistic and pushing on with vaccination so that we can get a high level of immunity in our population, starting with the most vulnerable,” she said.

“The numbers of cases (of the Manaus variant) in the UK are very low at the moment. At the present time I don’t believe there’s any threat to our vaccination strategy, or likely effectiveness.

“I think what it reflects is the fact that… what these variants will mean is that the vaccine manufacturers will be looking to make adaptations to the vaccine so that people can have boosters and some of those adapted vaccines are already being tested in clinical studies.

“So, I think it’s a note of optimism, but also a note that we need to go forward and work with vaccine developers to ensure that over time we have vaccines that are effective for our population.”

Experts do not so far believe that the P1 variant is more transmissible than the Kent variant, which in itself is more transmissible than the original pandemic strain.

Researchers at the briefing agreed that the current six cases of P1 in the UK was a low number, and it was thought multiple introductions of the variant would be needed for it to take off.