As of today, 17th April the deadly coronavirus has lead to an alarming 2 million+ infections and 145,000+ deaths worldwide.
Evidence thus far indicate that the virus can overwhelm even the most well resourced, developed countries like United States and United Kingdom. With no treatment and vaccination in sight yet, the only way right now to somewhat mitigate the damage has been through contact tracing, quarantine and enforcing social distancing.
What does the future look like? How long are we going to practice social distancing? Will this be a recurring disease? These are some of the questions answered in an article published in the journal Science this week.
In this paper Marc Lipsitch and colleagues, from Harvard used modelling and simulations, taking factors such as environment (recurrence of the virus in winter) and immunity into account.
The authors conclude that :
- Recurrent wintertime outbreaks of COVID-19 will occur after this wave of the pandemic ends!
- In the absence of available treatments prolonged or intermittent social distancing measures need to continue well into 2022.
- We need accurate tests to identify extent and duration of immunity amongst the population .
- Even if we are successful in eliminating the virus now, careful surveillance and monitoring should continue because there apparently is a possibility or resurgence of the virus in 2024!
According to this research article the incidence and duration of the coronavirus will depend on whether or not it will recur regularly like other coronaviruses after the current pandemic wave. This will essentially depend on how long people’s immunity will last after the COVID-19 infection. If the immunity developed due to COVID-19 is is short-term (about 40 weeks, similar to other coronaviruses like HCoV-OC43 and HCoV-HKU1) it might mean that the infections will recur every year and if our immunity lasts a bit longer (two years) we might see outbreaks once in two years. If we are lucky and the immunity to COVID-19 is permanent the virus could disappear for five or more years after the pandemic wave.
According to the authors one- time extensive social distancing measures, like the one were are taking right now will bring down the epidemic peak but resurgence of the infection might occur.
Social distancing strategies will mitigate strain on the health care system. Highly-effective social distancing measures could reduce SARS-CoV-2 incidence enough to make a strategy based on contact tracing and quarantine feasible, as in South Korea and Singapore. Less effective one time distancing might overburden the health care system. This is what we all know by now as “flattening the curve”.
Intermittent distancing may be required well into 2022 or until critical care capacity is increased substantially which is very hard to do even for developed countries or a treatment or vaccine becomes available. Increasing critical care capacity might also help in increasing immunity across the population.
All these results are modelling data and there are still a lot to be known about COVID-19. We do not know if we have develop immunity once we are infected and how long the immunity lasts. The idea of herd immunity is a good one but we don’t know yet if the immunity is permanent. Only time will tell.