With the recent rollout of a Covid-19 vaccine in the United Kingdom and America, a hopeful feeling that an end to this global pandemic sweeping the planet is within the foreseeable future has also swept the world. This piece will weave together what history taught us about the end of pandemics, how pandemics do / do not end; With some final thoughts on the topic of herd immunity concept.
How Have Pandemics Ended Historically?
The Spanish Flu (1918)
Taking a trip back through history, one past pandemic we can look back to in order to examine how pandemics end is the the Spanish Flu from 1918. First observed in Europe before spreading around the world, what is widely known as the Spanish Flu is considered one of the deadliest pandemics in history, infecting roughly one third of the world’s population at the time.
According to Time, the widespread end to the Spanish Flu Pandemic came about through effective use of social distancing, quarantining, ceasing of gathering places / activities, as well as other measures implemented now for Covid-19. National Geographic supported this idea and went on to claim that “In 1918,…studies found, the key to flattening the curve was social distancing” and found that cases in Philadelphia did not ease until gathering places and events were closed down. These measures, despite the overwhelming number of infections, meant that the virus struggled to find new people (without immunity) to infect in time with less people gathering in close proximity and strands began to fade and die out.
Washington Post reporting expands upon this idea of the virus dying out and believes that through both animal – human exchange / interaction as well as virus generations, the flu is has likely not died out completely, and is still with us today in a mutated form.
Swine Flu / H1N1 (2009)
The Swine Flu of 2009 was another pandemic that shook the world with a unique strain of DNA containing never seen before viruses. Swine Flu, also known as (H1N1)pdm09, was thought to have caused the deaths of between 151,700 and 575,400 people worldwide during the first year according to Centers for Disease Control and Prevention (CDC). The World Health Organisation (WHO), announced the end of the widespread Swine Flu pandemic on the 10th of August 2010, however on a micro level, the virus continues to circulate each year with the seasonal flu and cause a number of illnesses and even deaths.
Medically, How Do Pandemics End?
WHO in 2010 released a statement announcing the end to the widespread pandemic as well as outlining what a post-pandemic world looks like.
“We are now moving into a situation where the virus has spread to all countries…where no large and unusual summer outbreaks have occurred in either Northern or Southern Hemispheres, and where seasonal influenza A…and B viruses are being reported in many countries. Based on this overall picture, the evidence is strong that the recent influenza pandemic patterns are transitioning towards seasonal patterns of influenza.”
The statement clearly outlines key features they have observed globally to trigger the end of an active pandemic and the beginning of a post-pandemic era including a lack of abnormal or significantly large outbreaks, as well as the appearances of regular, seasonal flu. WHO makes sure to state that: “it is important to realize that the H1N1 (2009) virus can be expected to remain for many years.”
Emphasising that the end of the pandemic is not the end of the virus itself.
A Medical Perspective On Herd Immunity:
Another term widely thrown around over 2020 has been herd immunity. The concept that a population is protected from a virus once a certain amount of the population has become infected.
The concept became a popular topic when Sweden decided that they would confront the virus by allowing the nation to continue as normal without imposing significant rules or restrictions when the virus was first taking hold.
Sweden’s approach has been considered a failure, and along with much of the Northern Hemisphere moving into mid winter, the nation reported 9,659 new daily infections on the 17th of December. As Time put it: “Sweden and the U.S. essentially make up a category of two: they are the only countries with high overall mortality rates that failed to rapidly reduce those numbers as the pandemic progressed.”
Regardless of the ineffectiveness of Sweden’s approach, the conversion and concept of herd immunity has given people opposed to governmental restrictions and vaccinations a flag to rally around causing the frequent resurfacing of the herd immunity.
In an interview with Webmd, Director for the History of Medicine at the University of Michigan Dr. Howard Markel discusses how ‘herd immunity’ was never suppose to be used in the form and manner it has been this year; As a central argument against, and as an alternative to public health measures in favour of allowing the majority of a population to contract the virus. Rather, the term was developed (almost ironically for those opposed to vaccinations) in relation to mass immunisation of a community, particularly children.
Markel makes it clear that we would never naturally reach the population percentage required (between 60-90%) in order to have this 2020 interpretation successfully work. Calculations suggest the world is currently around 10% infected.
“Once we do achieve herd immunity the old fashioned way, based on vaccines, I think then we have a fighting chance of ending this chapter in human history.” – Dr. Howard Markel
Perhaps most clearly put by Dr. Markel, due to advancements in both technology and knowledge we are unable to use historical pandemics as direct historical references when trying to determine the length of Covid-19.
However, these previous crises can still provide on one hand a sense of hope in the techniques and measures being applied, whilst on the other, a reality check that the end of Covid-19 may be more of a fizzling whimper rather than the sudden bang we all expect and hope for.
Image courtesy of Yaroslav Danylchenko and Pexels