The remaining restrictions introduced to stem the spread of Covid-19 will be lifted in England on 19 July. This is despite rising infections, hospitalisations and deaths. This may seem totally counter-intuitive. Many countries remain focussed on supressing the spread of the virus through restrictions on social interaction. But the logic driving this decision is that the impact of the vaccines means hospitalisations and deaths in England are proportionally rising at a much slower rate than they were during previous up-ticks in infections.
This was articulated by the Secretary of State for Health and Social Care, Sajid Javid MP, in his statement to Parliament confirming the lifting of many restrictions when he said:
“The link between cases, hospitalisations and deaths has been severely weakened [by the vaccines]”
This is borne out by the data. Public Health England’s latest research estimates that vaccines are 91-98% effective at stopping those infected with the dominant ‘Delta variant’ (the highly infectious form of the virus first identified in India) needing hospital treatment. And the real-world figures tally with this estimate. They indicate the chance of hospitalisations has been reduced by a factor of around four and the chances of infections translating into deaths seems to have been reduced tenfold.
Put simply, the rate of infection is now much less important in the minds of policy-makers because the vaccines mean people’s chances of dying from Covid-19 are significantly reduced even if they catch it. But does this weakened association between catching and dying from Covid-19 mean we can all now relax?
Of course, vaccines are not perfect and surging infections will mean more hospitalisations and deaths. The UK Government has already warned that the ‘third wave peak’, expected this summer, could see 100,000 new daily cases. Some of these infections will be in people who are vaccinated (even the double jabbed), as the injections minimise the chances, but do not always stop, an individual catching the disease. However, these people are significantly less likely to get seriously ill, or die, as a result of the infection. Even still, scientists advising Ministers expect this to mean about 1,000-2,000 daily hospital admissions over the summer, and 100-200 daily Covid-19 deaths.
This looks dramatic, but can be contextualised when you explore comparative figures for deaths from other causes. For example, the NHS estimates 78,000 people per year – or, to put it another way, 213 people per day – die from smoking.
Of course, this is a simple, reductive argument that misses a huge number of ethical and practical questions – for example, smoking is a personal choice, catching Covid-19, however, is often the result of the actions of others. We have put many mitigation measures in place to stop passive smoking (i.e. minimising the impact that the personal choice of smoking has on the health of others), but with restrictions lifting, few statutory measures will remain in place to stop the ‘passive’ spread of the virus.
But even if – thanks to the vaccines – cases do not translate into hospitalisations and deaths at the rate we have seen previously, are there not other consequences? There is the question of whether the close contacts of Covid-positive cases need to self-isolate? As things stand that will end in mid-August. But one of the big questions policy-makers and epidemiologists still don’t know the answer to is – do more Covid-19 cases lead to more dangerous variants?
We know from the numerous variants that have forced England into extended lockdowns that more infectious forms of the virus have significant impacts on a nation’s ability to manage the spread of the disease. A vaccine-busting variant would have even more significant consequences.
Every time a person is infected, the Covid-19 virus goes through a biological process which means that it is replicated within a person. During this process tiny ‘errors’ can occur which create mutations. Many of these changes are harmless and simply disappear even before they are detected. However, the more chances the virus has to replicate, the more mutations you are likely to see and, in-turn, the higher the risk of a variant emerging that could spread more quickly or escape the immunity granted by vaccines.
Arguably more concerning is the potential ‘selective pressure’ vaccines put on the virus. 9 in 10 people in the UK are estimated to have some antibodies which could help them fend off the worst effects Covid-19. These viral-defences are obtained through previously being infected or a vaccine – both of which only grant limited protection against catching the disease, but significantly increase an individual’s chances of surviving or becoming seriously ill even if they become infected. This pre-existing but partial-immunity means there is a ‘pressure’ being put on the virus that could create conditions which favour a mutation that ‘gets around’ the antibody defences. This is because an environment in which antibodies limit but do not necessarily eliminate the virus’ ability to replicate is theorised to increase the ‘pressure’ put on Covid-19 to create a vaccine-evading version of itself.
Put simply, the potential for variants that can escape the protections we have built-up is possibly increased as more people become immune to existing variants.
To be clear, this cannot be deployed as an argument against vaccination. As without the vaccines, the existing strains of the virus would rip through the community with the devastating effect we have already seen. Furthermore, vaccines may not totally stop the spread, but they still play an extremely important role in reducing the growth of the virus by both lowering the likelihood of an individual catching the disease and spreading it even if they do contract Covid-19.
It is just a kind of cruel irony that as the overall number of vaccinations increases, this selective pressure on the virus also rises. This growing selective pressure will be coupled with the significant increases in cases as social restrictions ease, which only further enhances the chances of mutations, and consequently new, potentially dangerous, variants.
This is not a new concept in epidemiology – not even specifically in relation to Covid-19. Scientists have noted for some time that more infectious variants seemingly came to prominence in areas which faced significant first waves of Covid-19, and therefore in places where there was already a higher level of immunity (as a result of previous infections). This created a ‘natural’ selection pressure and so an environment conducive to more mutations – and more dangerous ones at that.
But can policy-making really be predicated on the unknown variations of a virus? And perhaps even more importantly, with the virus showing little sign of receding and vaccination rates heading towards 90%, if not now then when could restrictions be lifted? It is a balance of risks, with the outcome unknown.
So, although England will soon be both one of the most highly vaccinated and least restricted countries in the world, there are underlying risks which could still cause serious setbacks in its fight against the virus. Undoubtedly, all of the UK, as well as rest of the world, will be watching closely to see how things play out. The story of Covid in the UK may have more chapters to come.