Coronavirus disease 2019 (Covid-19) is a global pandemic. It has already considerably affected everything: individuals, institutions, and countries. We do not know how far and wide this virus will continue to transmit because the future is still indefinite. As of 14 June 2020, more than 7.8 million cases of Covid-19 have been reported in more than 188 countries and territories, resulting in more than 430,000 deaths; more than 3.72 million people have recovered. In terms of the scale of transmission and exerted impacts, countries can be classified into three main groups: the first group has already witnessed the peak of the pandemic, the second category is in the middle where cases are reaching the peak, and the third cluster is experiencing the beginning of escalation. Countries in the first category are fearing a potential second wave of the outbreak after easing the preventive measures put in place, such as lockdowns and the revoking of travel permissions. The virus caught the global community off guard, and its future course is still highly unpredictable; there is no crystal ball to tell us what the future holds and what the “end game” for controlling this pandemic will be. Although no one yet knows what the future holds for Covid-19, most experts seem to agree that it isn’t going away anytime soon. The epidemiology of other serious coronaviruses (SARS-CoV-1, the virus that causes severe acute respiratory syndrome [SARS] and Middle East respiratory syndrome coronavirus [MERS-CoV]) is substantially different from that of SARS-CoV-2; therefore, these pathogens do not provide useful models for predicting what to expect with this pandemic. Alternatively, our best comparative model is pandemic influenza. Since the early 1700s, at least eight global influenza pandemics have occurred, and four of these occurred since 1900-in 1918-19, 1957, 1968, and 2009-10. It is possible potentially to learn from past influenza pandemics as we attempt to determine a vision for the future of the Covid-19 pandemic. Identifying key similarities and differences in the epidemiology of Covid-19 and pandemic influenza can help envisioning several possible scenarios for the course of the Covid-19 pandemic. To visualize how the anticipated end of Covid-19 can unfold, three scenarios below have been analyzed. Of course, other developments can influence these scenarios, leading to different outcomes. The following scenerios give general trajectories of where we can be headed, and as such they must be considered.
The first wave of Covid-19 in spring 2020 may be followed by a series of repetitive smaller waves that occur through the summer and then consistently over a 1- to 2-year period, gradually diminishing sometime in 2021. The occurrence of these waves may vary geographically and may depend on what mitigation measures are in place and how they are eased. Depending on the height of the wave peaks, this scenario could require periodic reinstitution and subsequent relaxation of mitigation measures over the next 1 to 2 years.
The first wave of Covid-19 in spring 2020 may be followed by a larger wave in the fall or winter of 2020 and one or more smaller subsequent waves in 2021. This pattern will require the reinstitution of mitigation measures in the fall in an attempt to drive down spread of infection and prevent healthcare systems from being overwhelmed. This scenario is similar to what was seen with the 1918-19 pandemic. During that pandemic, a small wave began in March 1918 and subsided during the summer months. A much larger peak then occurred in the fall of 1918. A third peak occurred during the winter and spring of 1919; that wave subsided in the summer of 1919, signaling the end of the pandemic.
The first wave of Covid-19 in spring 2020 may be followed by a “slow burn” of ongoing transmission and case occurrence, but without a clear wave pattern. Again, this pattern may vary somewhat geographically and may be influenced by the degree of mitigation measures in place in various areas. While this third pattern was not seen with past influenza pandemics, it remains a possibility for Covid-19. This third scenario likely would not require the reinstitution of mitigation measures, although cases and deaths will continue to occur.
Whichever scenario the pandemic follows (assuming at least some level of ongoing mitigation measures), we should be prepared for at least another 18 to 24 months of significant Covid-19 activity, with hot spots popping up periodically in diverse geographic areas. As the pandemic wanes, it is likely that SARS-CoV-2 will continue to circulate in the human population and will synchronize to a seasonal pattern with diminished severity over time, as with other less pathogenic coronaviruses, and past pandemic influenza viruses have done. The ongoing patterns and nature of Covid-19 make it highly clear that there remains a considerable possibility for the next wave(s) of infection. Healthcare workers, governments, and international organizations, must become fully prepared to keep the viral spread under control so that to mitigate the impact the second-wave. Disinformation, rumors, and conspiracy theories must be countered with easy access to correct and helpful information. Simultaneously, it is indispensable that the healthcare systems should be greatly prepared in advance for any potential second wave to diagnose cases and offer the required treatment.