How the pandemic might play out in 2021 and beyond

One thing that has constantly been on my mind for the last 7+ months: The COVID-19 pandemic ¹. There’s so much I have read about it, heard about it, tried to learn about it, but a thought exercise around long-term implications of it fascinated me early on.

Thereafter, I spent a weekend looking at the how walking and driving habits had changed in various Indian cities.

More recently, as discussions around vaccines progress, and we learn more about SARS-CoV-2 and how it attacks the human body, I have also been thinking about what we can expect in the medium- to long-term as governments succeed or fail in controlling the spread of the pandemic.

The rest of 2020 will almost certainly continue more or less the same way as it has for the last 7 months, but what might the world look like in 2021?

Megan Scudellari for Nature, in “How the pandemic might play out in 2021 and beyond”, provides an important view into what epidemiologists are thinking:

Around the world, epidemiologists are constructing short- and long-term projections as a way to prepare for, and potentially mitigate, the spread and impact of SARS-CoV-2, the virus that causes COVID-19. Although their forecasts and timelines vary, modellers agree on two things: COVID-19 is here to stay, and the future depends on a lot of unknowns, including whether people develop lasting immunity to the virus, whether seasonality affects its spread, and — perhaps most importantly — the choices made by governments and individuals.

But also, don’t stop washing hands or wearing masks. It helps:

But there is hopeful news as lockdowns ease. Early evidence suggests that personal behavioural changes, such as hand-washing and wearing masks, are persisting beyond strict lockdown, helping to stem the tide of infections. […] The team concluded that if 50–65% of people are cautious in public, then stepping down social-distancing measures every 80 days could help to prevent further infection peaks over the next two years4. “We’re going to need to change the culture of how we interact with other people,” says Neto. Overall, it’s good news that even without testing or a vaccine, behaviours can make a significant difference in disease transmission, he adds.

So, what really happens in 2021 and beyond? We don’t know. Not yet:

The pandemic’s course next year will depend greatly on the arrival of a vaccine, and on how long the immune system stays protective after vaccination or recovery from infection. Many vaccines provide protection for decades — such as those against measles or polio — whereas others, including whooping cough and influenza, wear off over time. Likewise, some viral infections prompt lasting immunity, others a more transient response. “The total incidence of SARS-CoV-2 through 2025 will depend crucially on this duration of immunity,” wrote Grad, Harvard epidemiologist Marc Lipsitch and colleagues in a May paper14 exploring possible scenarios (see ‘What happens next?’).

That’s a somber reality.