“The single largest threat to man’s continued dominance on the planet earth is the virus”. “Outbreak”, the Hollywood pandemic thriller starts with this quote from Nobel Laureate virologist, Joshua Lederberg. While those dwelling in palatial offices around the world ignored the threat from global pandemics, Bill Gates sounded like a prophet, when he repeatedly warned of an imminent pandemic waiting to unleash its horrors. COVID-19 is the first truly modern pandemic, and carries the footprints of the great Spanish Flu of 1918 that is believed to have killed 50 million people worldwide with British India being the worst hit region. Historical records show that the Spanish Flu killed thousands in each of the now Lahore, Lyallpur, Gujranwala and Multan. After two and a half months of the emergence of the first case, numbers of mortality, morbidity and spread of the disease in Pakistan are heartening with the country largely evading the devastation witnessed in Europe and USA. A sense of complacency is creeping in our ranks. Subsequently, arguments on lifting or extending the lockdown continue to rage across the country. Another debate that has generally evaded the public discourse is the probability of a second deadlier wave of COVID-19 in Pakistan. Multiple waves of COVID-19 spreading throughout this year and well into 2021 is highly probable and a thorough risk assessment is the need of the hour Predicting pandemics is a difficult business as Elon Musk found out when he labeled the threat from Covid-19 as dumb. The accuracy of forecasting a pandemic depends on the availability of data which is often missing or insufficient during the actual spread. Ebola, the last major infectious outbreak, was widely mispredicted in its spread, with Center for Disease Controls USA estimating that 1.4 million people could be infected by the outbreak in Africa. However, to the relief of many, the actual number ended up lower than 30000. Owing to the paucity of data on the current outbreak, comparing and contrasting Covid-19 and Spanish Flu and understanding the culmination of the Spanish Flu pandemic in 1918 can give some valuable insights. The Spanish flu struck the Indian Subcontinent in three distinct waves, starting in the spring of 1918 till the mid of 1920. The second wave in the winters of 1918 is considered to be particularly deadly. A similar pattern of spread with a deadlier second wave of COVID-19 can spell disaster for Pakistan. Dr Anthony Fauci, Director of the National Institute of Allergy and Infectious Diseases, USA, has also warned of gloomy fall and winter for the US as threats of resurgence loom large. A basic difference between Spanish Flu and COVID-19 can bring some solace for the readers. While Influenza (flu) viruses notoriously morph from one strain to another, occasionally with deadly consequences, corona viruses are generally considered more stable and a sudden shift in mortality rate of COVID-19 is unexpected. Although misreported in various news reports, currently no evidence exists that any of the mutation has made Covid-19 more lethal or transmissible since its origin. Considering the mortality rate of 5% for Spanish flu in British India, the mortality of COVID-19 is also significantly lower with a recent lancet study putting the infection mortality ratio at about 0.66% globally. Another question that will define the future course of COVID-19 is the ability of the virus to become endemic in our community. The culmination of the spread of Spanish Flu can again provide some useful predictive value. It is believed that from the spring of 1920 to the end of that year, the influenza virus eventually worn itself out by excessive mutations, becoming incapable of further human infection. The relative stability of corona viruses might prevent an unexpected spike in mortality in the second wave of Covid-19, unlike the far deadlier second wave of Spanish Flu in the winters of 1918. However, the worrisome aspect is the probability of COVID-19 becoming endemic in our society due to the general ability of corona viruses to maintain their virulence and resist morphological changes. Likelihood of a second wave also depends on people who have been infected once, developing long term immunity. World Health Organization expressed in a statement that currently no evidence exists regarding infected people being permanently immune to re-infection. Historical medical records and research reports on the Spanish Flu pandemic provide some evidence of permanent immunity in victims of Spanish flu. The absence of a competent immune response to COVID-19 will also make chances of the second wave more probable. Possibility of reintroduction of COVID-19 in countries after local control also remains a potent threat as China witnessed a spike in imported cases of the disease once local spread was minimized. Reintroduction of the virus from other hotspots is a strong possibility as was observed during the second wave of Spanish Flu carried by soldiers returning to the subcontinent from trenches of Europe in that ill-fated fall of 1918 . Forgoing in view, any domestic approach to blunt the disease must align with the global efforts considering the extensive connectivity of today’s world. Whether Covid-19 will disappear, reappear in waves or simmer in the background as an endemic illness is still unclear. The probability of the current virus turning into a deadlier version remains low, however, multiple waves of COVID-19 spreading throughout this year and well into 2021 is highly probable and a thorough risk assessment is the need of the hour. The writer is a Doctor and Diplomat