The Forgotten Pandemic
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The 1957–1958 influenza pandemic was severe. The virus, H2N2, was insanely effective. With a death toll of 1.1 to 2 million people worldwide and an estimated fatality rate of 0.67%, the total number of infections might have been as high as 300 million — 10% of the world population at the time.
The first cases were reported in late 1956 in Guizhou, China — earning the pandemic the nickname “Asian Flu.” It was first transmitted to humans from wild ducks. By February 1957, the flu had spread to many other areas in China, including Hong Kong, where thousands were reported to be infected.
During our pandemic, many look to past examples in hopes that history can shed some light on what to expect. The most obvious candidate is the Spanish Flu, but as previously discussed, it is an extreme example — at least as far as we know.
Could the 1957 influenza pandemic be a more realistic historical precedent to shed much-needed light on the future of our pandemic?
H2N2 was less lethal but more infectious than COVID-19 — something that could lead to a similar number of fatalities. But history can only tell us so much. Our coronavirus belongs to an entirely different virus family, after all.
The 1957 influenza, despite its low death rate, would have had a much higher death toll if not for the quick development of a vaccine. It was the vaccine that slowed its spread and prevented tens if not hundreds of millions of new cases.
Scientists started working towards an H2N2 vaccine in May 1957. Three months later, in August, it was already finished and available to the public in the United States. By October, it was made available in the United Kingdom — which had an estimated total of nine million cases.
But the speedy vaccine wasn’t just thanks to the comparatively lax regulations at the time; it also had to do with the type of virus it targeted. Scientists simply have more experience developing flu vaccines.
Yes, even 1957 scientists had more experience with flu vaccines than we have with coronavirus ones.
The first effective flu vaccine had already been made by the 1940s. The first effective coronavirus vaccine is yet to be made. This is not to say that work hasn’t been done towards it; the MERS and SARS outbreaks were both caused by coronaviruses, and so they did bring some attention to the virus family. We do have an understanding of coronaviruses from which to build a vaccine; it’s just that our understanding of Orthomyxoviridae (the flu virus family) is more advanced.
By the time H2N2 became prominent in the United States, the vaccine was already being deployed. It still killed 116,000 Americans, but estimates say that number could have reached a million if not for the vaccine.
By late 1957, the worldwide availability of the vaccine was enough to start thwarting the spread of the virus.
A second wave did occur in 1958, but with much of the world population having already either recovered from the virus or taken a vaccine, it was nowhere near as grave.
H2N2 became part of the regular seasonal flu, and the world went back to business. It eventually mutated into H3N2 and caused the 1968 Hong Kong flu, which went on to become a pandemic of its own and killed an estimated one million people worldwide.
What it boils down to is that the 1957 influenza pandemic was different in many ways from ours. Both the lethality and infectivity of H2N2 vary wildly from that of SARS-CoV-2. Quick vaccine development played a huge role in ending the 1957 flu pandemic, as did infectivity and mortality.
More infectious but less deadly means more people were able to contract and recover from the virus and develop natural resistance to it.
By looking at the death toll alone, one might think that the COVID-19 pandemic might end up similarly to the 1957 flu — but that obscures all the underlying factors that might lead to very different results.
