India variant could lead to serious third wave of Covid in UK
It was all looking so good. After a brutal second wave in the winter, the lockdown combined with the swift rollout of vaccines forced infections, hospitalisations and deaths down to levels not seen since last summer. The vaccines performed better than expected, not only in preventing deaths, but in hampering the spread of the virus. Scientific advisers were confident about England’s cautious roadmap back to a life more normal: the worst, it seemed, was over.
Now, those same advisers are deeply worried that the new variant of concern from India, B.1.617.2, could undermine the hard-won achievement. The government strategy has been to ease restrictions as vaccines reach more people, aiming for a delicate balance that opens up society while preventing another wave that overwhelms the NHS.
Without the new variant, outbreak modellers advising Sage anticipated a modest third wave in July and August, with perhaps 4,000 to 11,000 more deaths, but nothing on the scale of the devastating winter wave.
But the new variant is here. What that means is still uncertain. Take the outbreak in Bolton and surrounding areas out of the picture and the situation in England looks far less alarming, suggesting the region may be an outlier. Yet some scientists working on B.1.617.2 believe it is destined to displace the dominant and highly transmissible Kent variant, B.1.1.7, in the UK and note that charts displaying the steep rise in cases look horribly similar to those that tracked the surge of the Kent variant in December.
Their concerns are backed by the Sage committee, which advised ministers on 5 May that pushing down cases of variant infections was now a “priority for policy”. A highly transmissible variant – one that spreads more easily than the Kent variant – “could lead to a very significant wave of infections, potentially larger than that seen in January 2021 if there were no interventions,” the experts said.
Epidemiologists are still wrestling with how transmissible the India variant of concern is. Public Health England believes it is at least as transmissible as the Kent variant, but preliminary work based on genome sequencing in India raises the prospect of it spreading up to 60% more easily.
To get some idea of what a fasterspreading variant could mean for the months ahead, modelling teams that feed into Sage worked up different scenarios. Assuming the vaccines hold up, more people could be hospitalised than in the first wave – putting the NHS at risk – if the variant is much more than 30% more transmissible, University of Warwick models show. At 40% more transmissible, hospitalisations could reach 6,000 per day, far above the peak of the second wave, and 10,000 per day if the variant is 50% more transmissible.
That is if we do nothing. If step three easing of restrictions in England on Monday is cancelled, the third wave will be far more modest, reaching 300 hospitalisations per day, even if the virus spreads 50% more easily than the Kent version. Holding off on step four on 21 June may be less effective: under that scenario a variant little more than 40% more transmissible could trigger more daily hospitalisations than seen in either UK waves so far.
A third wave of the coronavirus will drive people into hospital despite the mass vaccination programme. While the vast majority of older and more vulnerable peoplehave been inoculated, the vaccines are not 100% protective, and do not work in everyone. As a result, scientific advisers expect many of those hospitalised in the third wave to be vaccinated, just not well protected from their shots.
Millions more have not yet been called for their jabs. Among those will be people unaware they are clinically vulnerable. And so more deaths will duly follow. Modelling from the London School of Hygiene and Tropical Medicine, seen by Sage on 5 May, found that a 50% more transmissible variant could trigger a third wave with deaths peaking at 1,000 per day in late July. We have not seen those kinds of numbers since February.
Deaths are not all that matters. The decision to vaccinate older people first was based on saving lives and preventing the collapse of the NHS. The trade-off is more infections in younger, healthy people, and while they are much less likely to die from the disease they are at real risk of long Covid, in which patients continue to suffer from fatigue, brain fog and other debilitating symptoms long after they have overcome the virus itself.
So far, surge testing for B.1.617.2 and telling infected people and their contacts to isolate has not brought the variant under control, but it is a crucial part of the effort. Beyond this, ministers are looking to ramp up vaccinations in outbreak areas. In theory this could help by getting jabs to the old and vulnerable who have so far not come forward, and by slowing transmission, particularly if the vaccines are given to younger people who mix more.
But the protection from a vaccine comes two to three weeks after having the shot, by which time the variant may have spread far beyond the main clusters to areas where cases are still low. It may backfire if vaccines are diverted from low case regions to where the variant is now rife. The decision for ministers is how best to use the vaccine, and the answer is not straightforward.