Should we expect a second wave of COVID-19?

A number of countries, as well as several US states, have recently announced that they will soon be relaxing quarantine restrictions. Although this will be a great relief for many people, reopening too soon carries significant risks. Specifically, we could see a second wave of the coronavirus pandemic if the situation is not handled carefully

What we know from previous pandemics

The COVID-19 pandemic is often compared to the 1918 Spanish flu pandemic, the last pandemic that the world saw on this scale. During the 1918 pandemic, there were three separate waves, with the second one being the most deadly. We saw this pattern repeated in previous pandemics, such as the H1N1 influenza (also known as swine flu) in 2009, which also saw a second wave several months after the first.

Note that history has not shown us that a second wave is guaranteed. Neither the MERS nor the SARS epidemic experienced a second wave, and were brought under control after the first.

However, there are also specific characteristics of the novel coronavirus that make a second wave likely. We know that COVID-19 is a virus that spreads extremely efficiently, due to its being highly infectious — with its long incubation period — and the significant number of asymptomatic cases, meaning people can infect others without even knowing that they themselves are sick.

Furthermore, we know that other viruses in the coronavirus family usually peak in the winter months. This is because these types of viruses spread faster in colder, rainier weather, which may lead to a second wave later this year, just in time for winter in the Northern Hemisphere.

What could happen post-quarantine?

The World Health Organization (WHO) recommends a very cautious approach to easing restrictions, which involves staggering changes over time. WHO warns that due to the virus’ long incubation period, we will not see the impacts of easing restrictions until 10 to 14 days later, so it is essential to continue with hygiene and social distancing measures even as quarantine is relaxed.

However, people may be so excited with the end of quarantine restrictions and feel a false sense of victory over COVID-19, that they become too comfortable. In this environment, some may start to relax on hygiene, failing to wash or sanitise their hands or maintain proper social distancing.

Unfortunately, this will create the ideal environment for the virus to flourish once more, as there will still be a large percentage of the global population without immunity who can become infected. A recent study showed that relaxing restrictions too early would likely cause an increase in transmissions once more, starting a second wave of the pandemic.

We are already seeing evidence of the coronavirus resurging in places where it had already been brought under control. Even in the face of China’s apparent success in controlling the virus in Hubei province, the epicentre of the pandemic, they have seen outbreaks of the virus in the northern part of the country, such as the city of Harbin. Here, after weeks of close to zero community transmission, a number of new cases have emerged, sending the city back into lockdown.

Will we need to go back to quarantine?

Scientists and doctors are warning of not only the danger of a second wave of the coronavirus, but also the possibility that it will be more dangerous than the first wave. Experts advise that the novel coronavirus will not be eliminated until one of two things happen: either we develop a vaccine that is distributed throughout the world’s population, or we achieve herd immunity among the general population.

The Director of the USA’s Centers for Disease Control and Prevention (CDC), Dr Robert Redfield, is cautioning that the second wave will likely hit the US harder because it will coincide with winter and the regular flu season. This would put even more strain on the health system, making the second wave more deadly.

If we see a second wave of COVID-19, countries will need to impose quarantine restrictions once again. WHO is already warning that governments need to be prepared to reintroduce restrictions to manage subsequent outbreaks after they relax restrictions. It is also likely that the second round of quarantine will involve stricter rules than before, given the increased severity of this second wave.

This could mean even tougher restrictions on movement, and further limiting the justifications for people leaving their homes. If we don’t want to experience that, it is critical that we continue to implement exemplary hygiene and social distancing, even as the quarantine is lifted.

Regular hand-washing, or using a hand sanitiser that contains at least 70 per cent alcohol, will go a long way to prevent the spread of COVID-19 and avoid a second wave of the pandemic.