The Times title: Why can’t those given Covid vaccine just get on with their lives?
By: Tom Whipple, Science Editor | Chris Smyth
Date: 17 May 17 2021
“If the vaccines work, why do new coronavirus variants matter? Why is it the government’s business whether we drink in a beer garden or a bar, if the clientele are protected? And why should we be stopped from flying to Greece if whatever we pick up in Greece can be dealt with by our now-boosted national immune system?
These are reasonable questions, and starting to join them is a somewhat darker one: why should the whole country suffer from restrictions to protect those who are foolish enough not to have been vaccinated? If it is the unvaccinated who are getting hospitalised with the faster-spreading Indian variant, why can’t we just leave them to suffer from their own foolishness while the rest of us get on with our lives?
Before dealing with moral questions, there is the basic immunological one.
See article for diagram 1: vaccinated so far
These days, we call this virus the coronavirus. But, actually, it is merely a coronavirus. The other coronaviruses spread, unchecked and unnoticed. We don’t count cases, we don’t test hundreds of thousands a day to see if they have them but haven’t noticed. They might ruin your week but they won’t ruin the lives of others — or lock down a country.
The point of vaccines is they get us to that stage, to the stage where this too is merely “a” coronavirus. As Sir Jeremy Farrar, the head of the Wellcome Trust and Sage member, put it this morning, the vaccines “decouple” deaths from cases.
So given that most people at risk of death have been offered a jab, why should we be worried by a new more transmissible variant? Why haven’t we decoupled? Why aren’t the hospitalisations manageable, as they are with flu?
The simple answer comes in three parts: first, a small proportion of people are still at risk; second, a small proportion of a very big number can still be a very big number indeed; and third, a more transmissible variant means that, once again, we are looking at very big numbers.
See article for diagram 2: who has been vaccinated
More transmissible variants are a worry not so much because they spread faster, but because more people ultimately need to get them. The original Wuhan virus had an R of 3. That meant if one person got it, they sneezed on three others on average, those three others got it too, and the epidemic grew. If two of those three others were immune, though, it stopped growing.
The herd immunity threshold, in other words, was two thirds.
The new variant has, perhaps, an R of 6. This means the new herd immunity threshold, by the same logic, is five sixths. This in turn means that an extra sixth of the population — or 12 million people — need to get injected or infected before we are back at herd immunity.
So if we open up at what was previously herd immunity, and the new variant means it no longer is, there will be millions more cases.
Not all will be in the unvaccinated either. Before, the UK’s infection fatality rate — the likelihood of someone randomly infected going on to die — was about 0.6 per cent. The vaccines have slashed that but they aren’t perfect.
Vaccines reduce your chances of getting infected by about three quarters, and, modellers estimate, your chances of dying if you are infected by about two thirds. Some will still die. When you include the small pockets of unvaccinated vulnerable people, the new infection fatality rate is perhaps about 0.2 per cent. That’s enough, modellers believe, to once again cause a massive wave.
See article for diagram 3: vaccination progress
Even if it were one composed solely of the unvaccinated, even if we believed that was their choice and so their fault, this would still matter.
The aim of lockdowns has never been simply to stop people dying of the coronavirus. If it had been, the cost-benefit analysis against the harms of restrictions would have been much simpler.
The over-arching goal of government policy — going right back to the days before lockdown when the main line of defence was singing Happy Birthday twice — has been to stop so many people needing treatment at once that the NHS cannot cope.
The nightmare scenario has always been that so many thousands of people are sick that hospitals are physically overwhelmed, with patients who are eminently treatable dying in car parks because there are no beds to put them in and no staff to see them. If this happened, it is not just Covid-19 patients who would suffer but anyone who was ill for any reason would be at risk. This, in effect, is what has been happening in parts of India for the past month.
There is, though, still a path to summer freedom. To stop all this does not require another lengthy lockdown. This is not March 2020 or even January 2021. It requires more immunity — and we have a way to achieve that without relying on the virus to do it for us.
The road map out of lockdown has been a straight race between the virus and vaccinations. If the virus has got faster, then so must vaccinations — or, at worst, we must delay some freedoms until the jabs have caught up.
And if those vaccinations go into the arms of those not at risk, to ultimately save those who are at risk but refused, then so be it. An ethicist might object; an epidemiologist doesn’t care.”
———
0 Comments