80% of Namibians unvaccinated as new variant looms large

32 mutations of spike protein

26 November 2021 | Health

Henriette Lamprecht







WINDHOEK

Namibia is always concerned about the presence of viruses, in whatever form - and especially when 80% of the population is not vaccinated.

These are the words of health minister Dr Kalumbi Shangula on a new variant of Covid-19 that is causing great concern among scientists and has already been reported in two of Namibia's neighboring countries, Botswana and South Africa.

The B.1.1.529 - or Botswana - variant has 32 mutations in the spike protein of the virus that enables it to more easily evade the human immune system and spread to more people. Apart from four cases in Botswana and four in Hong Kong, the variant has fuelled the increase in cases in especially Gauteng where, at the time of going to print, 100 cases had already been reported.

This after the variant was recorded here for the first time on Tuesday.

Shangula said this test was part the country's monitoring system for all variants that may circulate in Namibia.

On whether Namibia would now consider ordering supplemental vaccines - with almost 270 000 doses of AstraZeneca and Pfizer expiring by the end of January - Shangula said the decision had been made to administer an additional primary dose in specific categories.

According to him, however, this decision was not made because doses will soon expire, but as part of "prudent vaccination management".

By yesterday, only 300 633 people had been fully vaccinated of a target of 1.5 million – set to be reached by March 2022 - to ensure 60% herd immunity.

‘Very unusual’

Professor Tulio de Oliveira of the KwaZulu-Natal Research Innovation and Sequencing Platform has said the new variant consists of a "very unusual constellation of mutations", with more than 30 mutations on the spike protein of Sars-CoV-2.

According to him, it has 10 mutations on the receptor binding domain where the highly contagious Delta variant had only two and the Beta variant three.

Meanwhile, Dr Tom Peacock, a virologist at Imperial College London, tweeted that the variant should "very definitely" be monitored due to the "horrible spike profile", because this makes it more contagious than any other variant so far.

"Exports to Asia imply that it can be more widespread than sequences alone can imply. The extremely long branch length and incredibly high number of spike mutations also indicate that this is cause for real concern," he wrote.

He emphasised that there were currently "super low" numbers in Africa and expressed hope that the variant was one of an "unusual group" and not as transferable as feared.

Difficult to predict

Professor Francois Balloux of the UCL Genetics Institute echoed De Oliveira’s remarks that the variant's mutations are an "unusual constellation", adding that they are "collected in a single burst".

This indicates that it could have developed during a chronic infection in someone with a weakened immune system, he said, possibly in an untreated HIV/AIDS patient.

Balloux said he expects the variant to be poorly recognised by neutralising antibodies, relative to the Alpha or Delta variants, and admitted that – at this stage - it is difficult to predict just how easily transferrable it may be.

"It could be present in other parts of Africa. For now, it needs to be closely monitored and analysed.

Officials from the World Health Organization met yesterday on the variant.

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- Additional information from Netwerk24, Bloomberg and The Independent.