Categories
Polio Vaccines

Learning from Polio

The polio epidemics of the late 19th and early 20th centuries had a swift and definitive effect on the path of modern medicine. The public feeling was overwhelmingly fearful – a survey of Americans in 1952 found that their fear of polio was second only to that of nuclear warfare. The development of treatment and disease management was paramount and changed not only medical practice but everyday life for millions of people. High risk venues – cinemas, pools, play areas, night clubs and bars – were closed to the public. Even short-term school closures – always a last resort – were implemented.

Protecting workers

One of the significant differences between Polio and subsequent viral outbreaks was its particular tendency to seriously affect children. The impact of a disease that targeted the children, usually the most precious people within a family made it an incredibly emotive and frightening illness. It can only be imagined how different the reaction to the Covid-19 pandemic would be if children were the most vulnerable to serious morbidity and mortality.

A disease that largely targets children does have one distinct advantage for its management; it has a much lower impact on the healthcare workers who care for the children. One of the most devastating aspects of Covid has been the burden it has posed to healthcare staff. With heavy, near-constant exposure to the virus, Covid infection has become an occupational hazard. Standard personal protective equipment (PPE) – paper masks, plastic aprons and gloves – offers some protection, but there have been many cases of nurses, doctors, and other healthcare and hospital workers contracting the disease.

With the basic PPE available in the polio epidemics of the early 20th century, staff with intense exposure to polio mostly remained safe, and the culture at the time for most nurses to be unmarried and live in hospital accommodation meant the risk of hospital attendants carrying the poliovirus home to their families was significantly reduced. Nursing culture has thankfully moved on from an insistence on total devotion, but there have been many examples of doctors and nurses moving from their family homes during the peak times of Covid infection so that they can continue to work without danger to their loved ones.

Quarantine and Medical Isolation

Since the earliest understanding of communicable diseases, attempts have been made to isolate and quarantine those affected. A passage in the book of Leviticus in the Bible gives instructions for isolating people with skin rashes while determining whether they’re infectious. Isolation is a bitter medicine but a good use-case of authorities trying to act for the greater good – still, the thought of leper colonies or sanatoriums designed with the sole purpose of keeping children away from their families is hard to justify with the sensibilities of modern medical ethics.

Hospitals designed for housing polio victims both for treatment and for medical isolation are some of the best examples of cohorted medical isolation in the history of modern medicine. Having designated spaces for groups of people with a single disease prevents the spread of that disease within a general hospital, where people are already sick and vulnerable. The ability to do this, however, relies on having the space, staff, and resources to open new wards or buildings for management of infectious diseases on top of the usual burden on healthcare systems.  

Medical isolation applies to those with a disease; quarantine is the word given to the process of isolating people who have been exposed to infection without yet becoming unwell. In the past, as now, the luxury of being able to quarantine as an adult depends on having the means to do so. For many, loss of income and financial insecurity is as sure a killer as disease. People need support to be able to stay isolated – without deliveries of provisions, the contagious leave their homes to seek food and risk infecting others; a basic model demonstrating the need for community support.

Mechanical Ventilation

The most deadly aspect of polio – the symptom which most closely determined whether someone would live or die – was its effect on a person’s ability to breathe independently.

An iron lung is a negative pressure ventilator – usually a machine large enough to hold a person, where their body is sealed in a near-airtight chamber with only their head emerging from one end. The pressure within the chamber is alternated to force rhythmic expansion of the chest, drawing air into the lungs and simulating normal breathing. The concept and early forms of iron lungs had been in development and use since the early 19th century, but the refinement and widespread availability of the device was solely thanks to the fight against poliomyelitis.

Iron lungs were relatively costly, cumbersome, and their availability was often outstripped by demand. At the time, the alternative to negative pressure ventilation – using external forces to effectively suck air into the lungs – was a basic form of positive pressure ventilation – pushing air into the lungs by positive force through the airways. Before the development of modern mechanical positive pressure ventilation, this was largely done by hand; throughout an epidemic in Boston there were around 1500 medical students whose time was devoted to using a bag and mask to physically ventilate polio patients.

This early positive pressure ventilation generally had better results with fewer complications than the iron lung, and can be thanked for the development of modern ventilators. With large groups of patients needing similar intensive ventilation treatment, not to mention carrying a serious infectious disease, people were cohorted into early form of intensive care units, with staff and equipment dedicated to the management of severe respiratory failure in polio.

Vaccination

Polio vaccination must be considered one of the most significant and successful public health operations of all time. From one of the most fearsome, debilitating and virulent diseases of modern times, polio has been almost completely eradicated worldwide. Two out of three of the strains of poliovirus are now extinct in the wild, and the third has been contained to only three countries, where vaccination efforts continue. The highly time-critical development of a vaccine during a spate of epidemics was a triumph of modern science.

The widespread uptake of the polio vaccine from the 1950s onward was never in doubt; people at the time were living in fear of the great potential tragedies of incurable polio, and the promise of an end to the disease was incredibly compelling. Vaccines in more recent times are not always met with the same enthusiasm; the availability of a mass media platform for anyone irrespective of qualification or evidence has resulted in small groups of people becoming resistant to vaccination programs. Hopefully with accessible education and targeted campaigning, large-scale vaccination can continue to be as successful as ever, whatever challenges new diseases bring.