Lessons from variants past should bring comfort amid tidings of gloom
‘Even if we do not manage to contain the spread, previous variants give us hope that it will not be as deadly as feared’
‘Most scientists think it is unlikely we will see complete immune escape from the vaccine’
It’s beginning to look a lot like Christmas. Which, as tradition dictates, heralds the advent of a new variant that threatens to slam the door on fun like a harassed innkeeper.
But lo! There may be a ray of light amid the omicron gloom: the ghosts of variants past.
It is worth remembering that although variants have undoubtedly caused problems, they have never created anything like the devastation forecast when they first emerged.
Take alpha. On Dec 14 last year, an ashen Matt Hancock told MPS that a mutation was spreading exponentially across Kent, London, Essex and Hertfordshire. The variant had actually emerged in September, but was only discovered after an investigation into why cases in Kent continued to rise during the November lockdown.
By the time authorities noticed there was a problem, the strain was out of stable, with more than 1,000 cases across 60 local authorities. Boris Johnson was forced to cancel Christmas for millions on Dec 21, with many areas put in Tier 4 restrictions.
We had the same issue with delta, which had arrived by at least February but was not identified until April.
Today we are in a far better position to track the virus and try to limit its impact. Less than 30 cases of omicron have been found so far and NHS Test and Trace is working to throw a ring around contacts to stop it spreading.
Even if we do not manage to stop the spread, which many scientists think is unlikely, the previous variants give us hope that it will not be as deadly as feared, and vaccines will still work.
Last December, the Scientific Advisory Group for Emergencies suggested alpha was between 34 and 74 per cent more transmissible than the original strain. A study published in January by World Health Organisation academics put it even higher, at 70 to 80 per cent.
Yet in July, Oxford University assessed the spread and found alpha had largely been carried by “superseeding” events. The scientists eventually determined it was about 30 to 40 per cent more transmissible.
Similarly, on Jan 23 the New and Emerging Respiratory Virus Threats Advisory Group estimated alpha was 30 per cent more deadly. By March, Public Health England (PHE) had determined it was no deadlier than the original strain. Although alpha was linked to a 34 per cent increased risk of hospitalisation, no significant difference in risk of death was seen.
Undoubtedly, alpha was responsible for the rapid rise in cases that led to the deadly winter wave, but if predictions had been right, we might have faced excess deaths closer to 100,000 rather than the 63,000 there were.
A similar pattern emerged with delta. On Apr 15, PHE announced that a variant first identified in India had been found in the UK. By then, 77 cases had been found, and within a month cases were doubling each week. On May 15, the Prime Minister warned it could “seriously disrupt” the roadmap out of lockdown, and after apocalyptic modelling suggested it could bring more than 200,000 deaths, Freedom Day on June 21 was delayed a month.
Yet the devastating third delta wave never occurred, as it became clear that vaccines were holding up well. Data from PHE showed the Astrazeneca jab was 92 per cent effective against hospitalisation and Pfizer 96 per cent.
Studies have since found it to be about 50 per cent more transmissible, with twice the risk of hospitalisation for the unvaccinated than alpha. It is without doubt a scarier variant, yet our vaccines held up.
It was a similar story for the original South African variant, now known as beta. In February, South Africa halted the rollout of the Astrazeneca jab after trials showed that beta all but wiped out any benefit of a vaccine.
Critics said at the time that the trial subjects had been young and healthy, which made the effectiveness against severe disease in those most at risk impossible to determine. They were right – later studies found that a single dose offered up to 80 per cent protection against hospitalisation and death.
Despite the emergence of omicron, there is cause for optimism. Unlike South Africa, where the virus is spreading rapidly, we have high levels of vaccination.
Nearly half the country has also now had a previous infection, according to Cambridge University, meaning T-cell levels will be high, and these long-term memory immune cells are far better at battling infections that look slightly different to the original virus than antibodies.
Most scientists think it unlikely we will see complete immune escape from the vaccine by the virus, with some suggesting this variant might bring a more infectious, but milder disease. Tidings of comfort and joy, if true.
So there are good reasons to stay merry and bright. As Dickens reminds us, “there is nothing in the world so contagious as laughter and good humour”. Even omicron can’t compete.