COVID-19 – what have we learned?

I did a talk at an IPC conference the other day trying to summarise what we’ve learned from the COVID-19 pandemic. You can see my slides here. I think (hope) we have learned a lot – and still have more to learn – about (in no particular order): PPE, transmission routes, testing and laboratory factors, vaccination, organizational transformation, guidelines and policy development, regulatory framework, outbreaks, non-COVID pathogens, antimicrobial stewardship, digital transformation, applied research, and the mental health of our workforce.

Firstly…learned vs. learnt?

I spent a little too long considering whether to go with learned or learnt? ‘Learnt’ was my assigned title, and the traditional English spelling, but I decided to go with ‘learned’, which is the “American English” spelling because I like the look of it more. Sorry if this bothers you.


Remember during the first wave of COVID-19? Those PPE shortages? And the masks around chins and on foreheads? One thing is for sure: the kind of dynamic risk assessment that we should always have been doing for PPE will never be the same again. It’s sad that one legacy of the pandemic will be an over-reliance on gloves and aprons for direct patient care. I’m pleased to say that now is the time to move away from that, and go back to most patient care being provided without gloves or aprons. Perhaps the biggest single controversy over the course of the pandemic has been the right level of respiratory protection for healthcare workers, with some arguing from the start that N95/FFP2/FFP3 respirators are required when caring for patients with COVID-19, and others that a surgical mask offers adequate protection unless undertaking aerosol generating procedures. National and local guidance has changed over time, and I think we are now at the point where most agencies and institutions are either recommending or allowing staff to choose N95/FFP2/FFP3 respirators when caring for patients with COVID-19. But, whatever PPE you are wearing, it’s so important to remember that the doffing stage is the most risky for self-contamination. Many hospitals introduced programmes of staff allocated to observing and supporting best practice related to PPE (see more on the Imperial PPE Helper Programme here). From a personal point of view, establishing the PPE Helper Programme was one of the most satisfying achievements during the pandemic – and I’m certain we significantly reduced staff exposure to SARS-CoV-2 at one of the most challenging times of the pandemic.

Transmission routes for SARS-CoV-2

Is it spread by droplets, aerosols, or by contact? That was the big question at the start of the pandemic, with the dogma being that SARS-CoV-2 is spread predominantly by droplets. As things have moved on and evidence has emerged, I think it’s fair to say that it’s looking like this was the wrong question to begin with. The distinction between droplets and aerosols is a bit of a false dichotomy. When somebody has a respiratory virus, they emit a range of respiratory ‘blobs’ of varying sizes. What begins as a big blob may become a small blob. So, I think in future we’ll be talking about whether an infectious disease is spread by respiratory or contact routes, and planning our precautions accordingly.

Testing and laboratory factors

The clinical laboratory has gone through it too. Initially, testing demand far outstripped supply. We could only test symptomatic patients at the start. As the pandemic has moved on, SARS-CoV-2 testing has become almost available universally on a population level, with the offer of free LFD tests in England. This sort of provision was unthinkable at the start of the pandemic, and illustrates the pace of change from a laboratory viewpoint. The current approach to patient testing in hospitals is coming full circle, and rapidly moving back towards a symptomatic approach to the management of COVID-19. The genomic epidemiology of SARS-CoV-2 has been tracked in close to real time, and has allowed for the rapid identification and characterisation of the variants as they have emerged, providing important insight to front-line clinical teams.


The rapid development and roll out of mass SARS-CoV-2 vaccination has perhaps been the biggest single success story of the pandemic. The pace of scientific discovery to develop the vaccines, and the sheer logistics of the roll-out have been impressive. And the result: an attenuation of the overall clinical impact of COVID-19, which has allowed us to change the way we manage the pandemic-related risks in our hospitals.

Organizational transformation

I remember vividly the moment when I realised from the predictive modelling that we would run out of critical care beds during the first wave. What followed was a week or two of intensive organisational transformation, to become a large acute medical and critical care provider. That led to the critical care surge across London, where ICUs were expanded at pace. There were unintended consequences of this, with impact on other HCAI transmission and AMR – but it was a testament to the flexibility and hard work of the staff involved that it was achieved. And organizational transformation hasn’t stopped there – there have been several waves of services slowing or shutting down completely and then reactivating with new operating models to meet the latest IPC guidance. I think it’s fair to say it’s been exhausting for everybody involved!

Guidelines, policy development, and regulatory framework

Keeping a track of the ever-changing national guidance has been a challenge to say the least. The Health Foundation has a cool policy tracker, where you can see what changed and when. I think we all remember the new IPC guidance that landed right on the bank holiday weekend in April 2020, which was pretty much cancelled for anybody working in healthcare. I don’t envy those having to write the national guidelines – but I do wish there had been more consultation with frontline experts, particularly early on. The regulatory framework has been an ever-changing environment too; just when you have got on top of one set of expectations, they are updated or outdated, so there’s been a sense of tail-chasing. That said, I have found some of the regulatory pieces such as the COVID-19 Board Assurance Framework a useful way to track organisational progress and flag risk.


Whilst we know that there were COVID-19 outbreaks during the first wave, and we were able to identify and manage some of them, testing availability and bandwidth availability from many staff in our hospitals limited the ability to respond. With clear epidemiological definitions, and more organisational capacity to respond, outbreak management activities during the Delta and Omicron waves have been much more comprehensive, with waves of healthcare-associated COVID-19 flowing along with waves of community infection. One of features of the pandemic, has been the involvement of staff as active vectors in outbreaks. This has required new ways of working between hospital infection control and occupational health services, which has been accomplished with, I think it’s fair to say, varying degrees of success!

Antimicrobial stewardship and non-COVID pathogens

Whilst we will be talking in a historical sense about the COVID-19 pandemic in 5 or 10 years’ time, we will be taking in a very live and real sense about the continued threat from antimicrobial resistance and non-COVID pathogens. I think it’s true that our focus on antimicrobial stewardship and non-COVID pathogens has been diverted by the pandemic. And now is the time to refocus on these.

Digital transformation

Who would have thought that we would be spending our days on Microsoft Teams or Zoom meetings and that working from home would be normalised so rapidly before the pandemic? These trends were there before the pandemic, with agile working being talked about in NHS circles. But the pandemic has brought it all in very rapidly, and created a permanent digital transformation of our workforce. Whilst this has undoubtedly been beneficial in many ways (not least reducing our SARS-CoV-2 exposures), it seems to have resulted in a proliferation of meetings. Are meetings now too easy to arrange? As we get back to face-to-face meetings, I hope we will think carefully about whether we really need that meeting! And what about digital transformation of our clinical services? I suspect that the digital infrastructure that has been built for virtual consultations will be here to stay, and that some of the digital innovations during the pandemic will find applications elsewhere to improve the efficiency of our services.

Applied research

Vaccination; COVID-19 treatments; new testing platforms and technology; SARS-CoV-2 hospital epidemiology; investigations into transmission routes to name but a few. The pandemic has sparked a wave of applied research and scientific discovery. It’s been a privilege to be involved in some small parts of this, to try to learn as we go and make changes to our practice accordingly.  

Mental health

The COVID-19 pandemic has required those working in the world of infection and infection control to go beyond our traditional boundaries. That’s been really hard, and it’s taken it out of us. To some degree, IPC has borne the brunt of organisational stress and anxiety. I am sure many readers (myself included) have been yelled at by colleagues and accused of all sorts of things. I will take some of what we’ve been through with me for the rest of my life – some good, some bad. So, now is a really good time to check in on our own and our colleagues’ mental health. Take time to reflect. And if you find yourself struggling, talk to somebody.  


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s