UCL News


Opinion: Why is the UK seeing near-record Covid cases?

30 March 2022

People are desperate to return to life as normal, but the rising number of infections is a reminder that this pandemic isn’t over, says Professor Christina Pagel (UCL Mathematics).

Christina Pagel

We’re living in two realities: one in which people have returned to living life as if Covid is over, and the other in which we are approaching record levels of infections, with an estimated 4.26m cases last week. Most of us know people who have Covid, work and education are being disrupted, and the NHS is under severe pressure again due to new patients and sick staff. Admissions with Covid are only 2% below the first Omicron peak two months ago and still rising. While about half are currently admitted primarily for other reasons, numbers are rising in primary Covid admissions too and admissions in over-65s are now 15% higher than their January 2022 peak.

The pandemic has changed, but the idea that it is over is false. Omicron represents a major variant, taking over in the UK in a similar way to Delta last summer and Alpha last winter. The ubiquitous narrative that the pandemic is over exists because most people (including the government) now believe at least one of the three big myths of the Omicron age. We need to move past these myths to firstly anticipate the future, and secondly do something to prepare for it.

The first myth is that coronavirus is now endemic, and just another disease we have to live with. We do, unfortunately, have to live with Covid. But the word “endemic” is commonly used in epidemiology to describe a disease that does not spread out of control in the absence of public health measures – in some sense, it means a predictable disease.

This clearly does not (yet) describe Covid. Globally, we have just experienced by far the highest surge of cases of the pandemic so far with Omicron’s BA.1 variant. Many countries in Europe, including the UK, are experiencing a significant second Omicron (BA.2) wave mere months after the first. Neither were predicted and they are rapidly changing our assessment of the evolution of coronavirus and the implications for protection from vaccination or previous infection. The chief medical officer, Chris Whitty, recently warned that new variant waves will come, but we don’t know when or what they will be like. People have declared Covid endemic after every previous wave and there is nothing special about this latest wave – they are still wrong.

Covid will probably become endemic – over some unknown timescale - but even then, endemicity certainly does not necessarily mean mild. There is a significant global burden of ill health and death, for instance, from endemic diseases such as TB and Malaria. As it stands, trying to ignore a disease that is still so unpredictable feels a bit like turning your back on a hungry tiger in the undergrowth.

Next, we have to debunk the myth that coronavirus is evolving to be milder, and each new variant will be milder than the last until it becomes a common cold. New variants of Covid have arisen rapidly over past two years. Each variant of concern has spawned several offshoots – like our current BA.2 wave – but most gamechanging new waves we’ve seen have come from variants that have evolved completely independently from each other. Omicron did not evolve from Delta and Delta did not evolve from Alpha, Beta or Gamma. There has been no progression through successive variants, and no building towards “mildness”.

It is also simply not true that viruses always evolve to become milder. What drives evolution is transmission: variants that infect more people will thrive. Because most Covid transmission happens while people have no or few symptoms, severity is not a driver of evolution but instead a byproduct of whichever mutations improve transmission and how they interact with existing levels of immunity. For Alpha and Delta, this led to greater severity and for Omicron (somewhat) less severity, but this was an evolutionary accident. The next variant could easily be more severe again.

While many assume that the four other coronaviruses that cause common colds started as epidemics and then eventually became the mild colds of today, we have no idea whether this takes years, decades or centuries, or even if it is inevitable. We simply do not know much about the long-term evolution of new coronaviruses in humans.

Finally, there is the pernicious myth that we’ve somehow “finished” our vaccination programme, and there is no point in waiting to return to normal. The UK does have a high level of vaccination, particularly in older, more vulnerable populations, and the initial two dose rollout in adults is largely complete. Unfortunately, immunity from vaccines wanes over a matter of months – mostly against infection, but also against severe disease and death.

Boosters help, but also mean it’s more a question of whether you are up to date with vaccination rather than just vaccinated. Around a third of over-12s are yet to receive their booster in the UK, and we’ve only just started another booster round for people who are over 75 or clinically extremely vulnerable. Most children, meanwhile, remain entirely unvaccinated.

As the world is increasingly either vaccinated, infected or both, the way the virus will evolve to improve transmission is by becoming better at evading our immune system, like Omicron did. This means that existing vaccines (targeted to old strains) and previous infection will become less able to protect us from new infection, as tens of thousands of people are finding out with their second (or more) Covid infection. As Prof Danny Altmann argues, instead of relying on frequent boosters of the same vaccines, we must develop better and longer lasting ones.

We are currently pushing existing vaccines to their limits with high infection levels, but we should instead be supporting them by reducing transmission. Returning to normal behaviour does not return us to normal life. It returns us to a life with more disruption, more sickness and more strain on the NHS. But we can certainly learn to live with Covid better.

We need to rediscover our ambition to improve public health as we did in the 18th and 19th centuries. We can introduce serious upgrades to infrastructure: better ventilation, less crowding, increased air purification and sterilisation, more green spaces, changed work practices. We can also tackle inequalities with improved sick pay and housing and population health. All of this is beneficial over and above Covid. We can do it, but we first need to stop believing in these persistent myths.

This article first appeared in The Guardian on 30th March 2022.