As we have often found with Covid-19, no sooner does a path seem to emerge out of the woods than the trees close in again. On Monday, the Prime Minister confirmed that the further relaxation of lockdown rules – including the reopening of indoor hospitality – would go ahead as planned next week. Daily totals of deaths from Covid-19 have been running at very low levels – indeed deaths from all causes are now running 7.3 per cent lower than the recent five-year average, according to the ONS.
Yet this morning, Sage is meeting to discuss whether any further reopening of the economy should be delayed – owing to a worrying rise in Britain in the number of cases of B.1.617.2, one of the Indian variants of Sars-CoV-2. In advance, Professor James Naismith of Oxford University told the Today programme that he thought local restrictions would not be sufficient to contain the spread of the new variant. So far, 727 cases of the variant have been picked up in Britain, with a particular hotspot in Bolton. Commentators have noted that B.1.617.2 has taken only a third as long as the South African variant did to reach levels of prevalence in Britain – although of course the number of cases detected isn’t the same as the numbers which have actually occurred. Increased monitoring of variants has inevitably increased the likelihood that cases of variants will be detected.
The arrival of B.1.617.2 has coincided with a devastating second wave of Covid-19 in India, but is it a greater threat than any other variant? We don’t so far have a great deal of data on the transmissibility and ability of B.1.617.2 to sidestep vaccines. Some of the concern, however, derives from reports of a care home in Delhi where 33 staff members aged between 27 and 77 were found to have been infected, in spite of having received two doses of the Oxford/AstraZeneca vaccine. In most of these cases, the B.1.617.2 variant was to blame. However, none of the 33 staff members fell seriously ill, suggesting that if the variant is able to get around the AstraZeneca vaccine, it may still be having a useful effect in preventing hospitalisations and deaths.
The Cambridge Institute of Therapeutic Immunology and Infectious Disease has published a paper – yet to be peer-reviewed – which looks at the ability of the Pfizer vaccine to deal with the B.1.617.2 variant. This was a laboratory study using blood samples rather than an epidemiological study using data from infections in the community. It found that the spike protein of the new variant has ‘modest ability’ to avoid neutralising antibodies. The team concluded that mutations in the spike protein in the B.1.617.2 had helped the virus bypass immunity gained from natural exposure to the Covid virus among many Indians last year – in some parts of India between 20 and 50 per cent of people were estimated to have acquired some degree of natural immunity. However, the Cambridge team also concludes that ‘at population scale, extensive vaccination will likely protect against moderate to severe disease and will reduce transmission of B.1.617 given the in vitro neutralisation data we and others have presented.’
In other words, it believes that while the B.1.617 variant has some ability to sidestep vaccines, the high level of vaccination in Britain should still prevent a new wave of serious disease here.