Pandemics: The Space Between History & Novelty

BY MOREEN NG

When the emergence of a novel SARS-Cov-2 viral strain was first reported in January 2020, the virus had already spread to four countries. Two months later, the World Health Organization (WHO) officially declared Covid-19 a global pandemic and global public health emergency of international concern (PHEIC) on March 11, 2020.¹ Acknowledgment of the virus as a global threat lagged behind its spread, while national and international responses differed from one another. Global solidarity was absent when it was most needed, and thus the world paid the price for inaction at the highest level, disproportionately impacting the most vulnerable communities. 

This year marks the fourth year since the Covid-19 pandemic began. Vaccine development and implementation of proper screening protocols have significantly decreased mortality and hospitalization rates, leading the WHO to cease Covid-19’s PHEIC designation.¹ However, Covid-19 is still widely present, and novel variants remain a global threat.  

It is inevitable that new variants and strains emerge in the future amidst increasing globalization. History until this present moment has proven that our approach to combating these strains must be rapid and collaborative. Furthermore, governing institutions at all levels must be prepared: to be ready is to stay ready. And perhaps a retrospective visit to how we responded to four of the deadliest pandemics in recorded history may provide insight on how to stay ready. 

To start, it is helpful to define what classifies as a pandemic—a somewhat ambivalent term. The International Epidemiology Association’s Dictionary of Epidemiology defines a pandemic as “an epidemic occurring worldwide, or over a very wide area, crossing international boundaries and usually affecting a large number of people.²” The WHO outlines outbreaks in phases and classifies a pandemic as Phase 6, which is described as “community level outbreaks in at least one other country in a different WHO region.³”

Throughout history, pandemics have served as catalysts, shaping policy, society, and science. Understanding the impact and necessary response to pandemics is dynamic and complex; the effects of pandemics vary across different communities and countries. Still, a look into how governments responded to previous pandemics will reveal prevalent lessons that we can still learn from today for our future. 

1918 Influenza Pandemic

Known as the deadliest pandemic since the Bubonic plague, the 1918 flu pandemic, characterized by a subtype of Influenza A virus H1N1, was estimated to infect over 500 million worldwide, killing from 50 to 100 million.⁴ Though the 1918 Influenza pandemic was commonly known as the Spanish flu, which arose from the false impression that virus first emerged in Spain, research has deduced that the virus originated in the United States. With the first case reported near a U.S army camp in Haskell County, Kansas, the virus rapidly spread to various states and U.S involvement in World War I.⁵ As the technology needed for vaccine development had yet to exist — genomic sequencing available decades later revealed that the 1918 H1N1 viral strain stemmed from the H1N1 avian virus⁶ — control over the spread of H1N1 virus solely relied on public health policy. In the U.S, most state governments enforced a public gathering ban and shut down settings such as public schools and movie theaters.⁷ Non-pharmaceutical interventions such as self-quarantine, social distancing, and mask mandates proved to be effective in controlling spread of the virus, curbing mortality rates in US cities by more than 80%.⁸ However, non-pharmaceutical interventions could only sub-optimally prevent the spread of the virus due to lack of an effective vaccine in conjunction with varying in-state and national public health measures. Still, the medical and policy response to the 1918 pandemic displayed how efficacious non-pharmaceutical interventions and public health policy were. 

History marks 1920 as the end of the 1918 Influenza pandemic, but remnants of the 1918 pandemic persisted throughout time and are even present today. While population immunity is a strong defense, viruses are highly adaptive, mutating and evolving to novel, infectious genetic variants. Following the 1918 pandemic, several Influenza outbreaks occurred in addition to three Influenza pandemics in 1957, 1968, and 2009. 

1968 Hong Kong Flu Pandemic

The 1968 pandemic, also known as the Hong Kong flu, claimed up to four million lives worldwide and was caused by an antigenic shift of the previous Influenza A viral strain H2N2 responsible for the 1957 Influenza Pandemic.⁹ While known as the Hong Kong flu, previous research suggests that the virus first emerged in the Guangdong of the People’s Republic of China (PRC).⁹ Information on the origins of the virus and early signs of the outbreak are elusive because the PRC was not a part of the WHO or United Nations until 1971,¹⁰ which impeded data collection and, thus, knowledge of an emerging epidemic. Though various reports of alarming epidemics emerged, these reports were buried under the looming geopolitical instability as The Cultural Revolution consumed the PRC and the broader international community was caught in the Cold War.¹⁰  By the time more Influenza-like cases were reported in various countries, a pandemic was already imminent. Over 100,00 lives were lost in the U.S where the spread of the virus was accelerated by the return of Vietnam War veterans.¹¹ 

The impact of the virus was immensely reduced in comparison to the 1918 pandemic due to early collaborative efforts and establishment of the Global Influenza Surveillance and Response System (GISRS) by the WHO following the 1957 Influenza pandemic.¹⁰ The GISRS consisted of a network of laboratories across countries part of the WHO, which enabled identification and exchange of viral strains used to synthesize vaccines.¹⁰ This ultimately led to development of a vaccine in approximately 4-5 months.¹¹ Progress of vaccine development was slowed by the limited egg supply, as vaccines were made through injection of the virus into fertilized eggs to generate inactivated virus for the flu vaccine.¹²

The 1968 Influenza pandemic reignited the importance of a global surveillance system for outbreaks whose benefits can only be fully realized through an inclusivity of the global community. Simultaneously, the 1968 Influenza pandemic revealed how faulting the country in which the virus originated from can impede response to pandemics. Upon the incorrect impression of a virus originating from Hong Kong, global rhetoric quickly turned against Hong Kong, cascading a cycle of blame and scorn. Epidemiologically, it is crucial to understand the origins of a virus to track its footprints across the world. However, as we will learn once from the global response to Covid-19, a cycle of blame and scorn reaps no benefit. 

1980s HIV/AIDS Pandemic

The HIV (human immunodeficiency virus) and acquired immunodeficiency syndrome (AIDS) pandemic was hypothesized to arise from the transmission of a simian immunodeficiency virus (SIV) to humans, originating in Central Africa in the 1920s.¹³ The molecular basis of HIV is characterized by weakening of the immune system, and the virus is transmitted by certain bodily fluids (blood, semen, vaginal fluid, anal mucus and breast milk).¹³ Two HIV strains exist, HIV-1 and HIV-2, the former of which is the more infectious strain.¹³ Since the start of the pandemic, 86 million people have been infected with the HIV virus and about 40 million have died of HIV.¹⁵ Contrary to how one can recover from Influenza, an HIV infection entailed a life-long diagnosis—a diagnosis that has been historically accompanied by stigma and social exclusion. 

In 1981, HIV was clinically diagnosed in the United States from case reports of severe lung infections and Kaposi’s Sarcoma that disproportionately affected young gay men.¹⁴ Despite increasing reports of deaths from “gay cancer,” there was minimal government attention and action towards, leading to the establishment of organizations such as the Gay Men’s Health Crisis (GMHC) in 1982.¹⁴ Further international attention would arrive a few years later when the WHO created the Special Programme on AIDS in 1987 and the U.S. congress passed the Ryan White Act in 1990, which allocated $220 million dollars towards treatment.¹⁴ With the acquired investment in HIV/AIDS screening and treatment, ELISA blood tests became available, and  effective protease inhibitors and antiretroviral therapies were introduced in 1995,¹⁴ significantly decreasing the mortality rates by 90%. However, this statistic obscures the disposition effect of HIV on low and middle income countries that lack funding for healthcare systems with HIV screening and treatments. Currently, HIV remains to be the leading cause of death in Sub-Saharan Africa.¹⁵While HIV therapeutics now exist, they are not a cure nor are they available for all HIV patients. In 2022, 39 million worldwide lived with HIV and 630,000 had died from HIV.¹⁵ The initial, false impressions that HIV solely impacted gay men positioned them as outcasts, stigmatizing a community and preventing adequate initial support. Lessons from the HIV/AIDS pandemic touch on the social and political factors of pandemics. 

2009 Swine Flu Pandemic

The 2009 swine flu pandemic was characterized by a novel form of Influenza A virus that has never been encountered. When initial reports of Influenza-like cases were reported in Mexico, it was suspected that a variant of 1918 H1N1 strain was responsible. However, research unveiled that the 2009 virus was a product of a triple reassortment between human H1N1, avian H1N1, and swine viruses.¹⁶ While the mortality rate was low, the virus was highly contagious and particularly prevalent among adolescents and young adults. Maximized by globalization, the virus reached 122 countries in only six weeks, infecting 60.8 million worldwide.¹⁷

Vaccine development was fairly rapid with a robust vaccine campaign.¹⁷ The 2009 Swine flu pandemic was a testament to the ever evolving zootic nature of flu viruses. Thus, it is crucial to always be prepared to adapt to the unpredictable nature of flu viruses—a persisting problem in the present day. Simultaneously, the 2009 pandemic reveals how crucial it is to enable equitable access to treatment. Mexico received a flu vaccine shipment three months after the U.S. vaccine campaign.¹⁸

Historical trends have shown that the country from which the virus originated is often the most impacted; thus, response efforts should ensure equitable access to vaccines to control spread of the virus.

Now & Beyond

A look into the four deadliest pandemics in recorded history reveals that we still face some of the same difficulties in our response to Covid-19 and preparation for subsequent novel viruses. From a scientific perspective, the precise mechanism of viral infection and cross-species transmission remain unclear. Decades of scientific research have advanced our knowledge of viruses that has led to the development of antiviral medications and vaccines, notably the Covid-19 vaccine, which was the first FDA approved mRNA vaccine. And we must ensure that viral scientific research continues for decades more, for no virus is the same as its predecessor or ancestors. From a policy perspective, national and global health policies must improve current guidelines to better detect emerging novel strains then coordinate outbreak surveillance and response methods. It is undeniable that health surveillance is inherently political. The benefits of scientific advancement to humanity can only be fully realized through collaboration and effective policies established by international unity under global health governance. Since 1918, science and policy have advanced immensely. Specialized industries and governing institutions have been established with the intention to prevent future outbreaks. But more can and needs to be done.  

A long-term, collaborative investment and a multi-sectoral approach are necessary to prevent and prepare for pandemics. Our present preparation is the product of decades of research and development. History has proven that the amalgamation of pharmaceutical and non-pharmaceutical interventions is necessary for the most optimal preparation for future outbreaks. Pandemics have served as a repertoire of history and novelty. From surviving each pandemic, we gain lessons on how to approach future challenges. Our present and future duty is to apply these lessons to close the gap between history and novelty.

Moreen Ng is a senior in Yale College.

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