One year on

It is almost exactly a year since my first COVID-19 blog post was published here on 13th March. So here some thoughts on the last pandemic year.

It has been a very mixed year: traumatic – watching case and death numbers climb, experiencing illness and deaths of friends; challenging – lockdowns, seeing their impact on friends and colleagues; fascinating – experiencing the outbreak as a modeller and statistician.

Having spent the last 12 months working almost exclusively on the epidemic and having written eleven The Conversation pieces and many blog posts, I have been thinking about the wrong and right things I said and wrote.

I got spectacularly wrong the speed at which the UK – and other countries – would proceed with vaccination. I expected the roll-out to be slow, with logistics of delivering the mass vaccination while maintaining social distancing, as well as vaccine hesitancy as main problems.

Israel, UK, and other countries have shown that it is possible to vaccinate at a scale and speed I would not have thought possible. Yes, there have been hiccups and delays – I still don’t understand the low uptake in Germany – but overall this is an impressive result.

Speaking about vaccines, I actually expected more side effects, including fatalities. As it has turned out, the available vaccines are indeed remarkably safe at least in the short term.

I initially got masks wrong. I imagined that a cotton mask would not provide efficient filtration. Although the mode of spread is still debated, with a non-negligible potential of air-borne transmission, there is very good evidence that masks help to suppress spread.

I underestimated the potential of SARS-CoV-2 to mutate. Early in 2020 I followed the then prevailing opinion that coronaviruses have lower potential for producing highly infectious strains. Unfortunately, the experience of winter months of 2020/21 has shown how wrong this was.

What I got right? I would claim three interlinked things. Firstly, even from early on, I have been convinced that we are in for a long fight with the virus. Working with pests and pathogens has taught me that they are notoriously difficult to eliminate and eradicate.

I have been very impressed with how China, Australia, New Zealand, Taiwan and Vietnam have so far managed to almost eliminate the virus. Their’s has been a high cost of a strict, sometimes brutal, clamp down on social interactions, as well as the lack of international travel.

As long as the virus exists elsewhere, the #ZeroCovid situation is unstable, as the Scotland summer 2020 example clearly demonstrates. So the #ZeroCovid strategy needs to be maintained. I do not know how much will there is in societies to do so.

Secondly, that it is only by building trust and coordination across different levels of society that we can stop the epidemic. Very early on I realised that the economic and social inequalities are going to have a huge impact on the spread and persistence of the disease.

Thirdly, the year has put me in a battle with the “herd immunity”-Barrington Declaration proponents. I still think that #ZeroCovid was the best strategy for containing the disease – and possibly still is.

#ZeroCovid approach consists of a rapid, deep lockdown, long enough to reduce the numbers, followed up by an efficient test-and-trace programme backed up with incentives to quarantine, and efficient border control.

I am actually amazed at how well our 2012 paper predicted the pandemic. Our model is very simple and we only looked at individual decisions rather than governmental ones. But we predicted that the #ZeroCovid strategy is economically optimal for highly infectious diseases.

However, this strategy borders on another one of continuing lockdown-release cycles, R constantly close to 1, and a long, expensive, unsuccessful epidemic. By the way, this paper has now been cited by 134 other studies (Google Scholar), 98 citations in 2020-21.

As we approach a third (or is it a fourth?) lockdown, I am painfully aware that I should have been much more vocal about #ZeroCovid throughout 2020-21. Maybe it is not too late…