A look back at how vaccines have eradicated some of humanity’s deadliest diseases

By Chris Pleasance

A recently released set of graphs reveal how some of the deadliest and most infectious diseases in human history were all but wiped out after vaccines were developed to fight them.

Smallpox, measles and polio together killed hundreds of millions of people throughout human history, while leaving many millions more with life-long disfigurements or disabilities.

But with the help of vaccines, smallpox has now been eradicated worldwide, polio cases have been reduced by 99 per cent, and measles infections have also drastically reduced.

The charts were published by Max Roser, an Oxford University researcher and founder of the Our World in Data website, as coronavirus vaccines start rolling out, raising hope that life may soon return to normality.

A smallpox victim and vaccinated friend in 1919.

Oxford University, working alongside drug giant AstraZeneca, has developed one of the world’s first coronavirus vaccines which has proven up to 90 per cent effective in late-stage trials and is in the process of being approved for use on the public.

Mr Roser wrote: “Infectious diseases that once disfigured, pained, paralyzed, and killed many of our ancestors have disappeared far from our lives and memories.

“Today as we face the COVID-19 pandemic, it is the first time for many of us that we experience for one infectious disease what our ancestors experienced for a whole range of them. Just as they were without protection against the diseases discussed previously, we are now facing a pathogen that we have no treatment for and no protection from.”

He continues: “And now, just as back then, our best hope is science… To end the suffering that COVID-19 causes our best hope is a vaccine against the virus.”

As an example, Mr Roser used data on three of the deadliest and most infectious diseases that vaccines have been developed for – smallpox, polio and measles.

Smallpox is thought to have been one of the deadliest diseases in human history, killing more than half a billion people starting in the time of the ancient Egyptians right up until 1978. Almost a third of those who caught the disease died from it, while survivors could be left with disfiguring scars that they carried for the rest of their lives.

That prompted English physician Edward Jenner to develop the world’s first vaccine, using the related but milder cowpox disease to protect people against smallpox.

Data shows that deaths in London from smallpox gradually reduced as the vaccine was administered starting in 1796 and, barring a major outbreak in the 1870s, fell consistently over the ensuing decades. The disease was declared eradicated from the UK in 1930, and in 1980 became the first disease to be wiped out worldwide using vaccination.

While progress with the smallpox vaccine was slow, data shows more dramatic results with vaccines against polio and measles, which were administered faster. In the first half of the 20th century polio outbreaks were common, especially during the summer months, with most patients being children.

While most cases of polio were mild, severe cases could leave children with partial paralysis or cause death by paralysing the muscles that control breathing. The only treatment for those patients was to be placed into an ‘iron lung’, where they may have to stay for weeks, months or even years.

Paul Alexander, a 74-year-old from Texas, caught polio in 1952 aged four and had to be put into an iron lung where he remains to this day.

In 1955 American Jonas Salk developed a vaccine against the disease which had an immediate impact on the number of cases and deaths from the virus. Within just a single year the number of paralytic infections almost halved, data shows, and by 1979 the virus had been wiped out in the US.

Until the polio vaccine was introduced in the 1950s, many victims were put in ‘iron lungs’ to survive.

Measles is another highly infectious disease that can cause life-threatening symptoms, including pneumonia and swelling of the brain. The disease was first described in the 9th century in Paris, and during the first decade of data-gathering in the US – from 1912 to 1922 – it killed an average of 6,000 Americans every year.

Between 1953 and 1963, when a vaccine was first developed by John Enders, it is thought that almost every child in the US was infected with measles at some point before they turned 15.

While measles cases rose slightly the year after the vaccine was introduced, they fell dramatically in four subsequent years. The disease was declared eradicated from the U.S. in 2000, but has since made a resurgence as vaccine rates have dropped.

Globally, it is thought just 70 per cent of children are now given the recommended two doses of vaccine each year, while cases are now at a 20-year high and deaths from the disease have increased 50 per cent in the last four years.

As of today, coronavirus has infected at least 73 million people since emerging in China late last year, and has killed at least 1.6million. Those numbers are widely thought to be under-estimates due to problems with testing, especially during the first wave of infection.

In order to control the virus, governments around the world have plunged their populations into lockdowns which have crippled economies and caused a global recession with effects likely to be felt for years to come.

That global impact has pushed scientists to create a vaccine against the disease in less than 12 months, in a process that can normally take years or decades.

The first vaccine to report data from large-scale trials, developed by Pfizer and BioNTech, has been approved for use in the UK and US with mass vaccination programmes now underway – with the EU expected to approve it before Christmas. Two other vaccines, developed by Moderna and Oxford-AstraZeneca, are also expected to gain regulatory approval in the coming months.

Safety trials have shown that the Pfizer and Modrena vaccines are up to 95 per cent effective at preventing serious illness caused by the disease, while the Oxford jab is up to 90 per cent effective with an average of 70 per cent. It is not yet clear whether these early vaccines will prevent people from catching the disease, but they should help to stop people from dying of it.

Moderna has since submitted data suggesting that its vaccine can prevent people from catching the disease – helping to break up chains of infection and stop the disease from infecting those who have not yet been vaccinated.

However, the jabs have proved controversial with many saying they will refuse to take them amid safety concerns, despite experts and medical regulators insisting that they are safe. In America, 39 per cent of people polled in November said they won’t or probably won’t take the vaccine – though half of that group said they could change their minds if more data becomes available.

Skepticism is also high among European nations, with only around a third of those in Sweden, Germany and Italy ‘strongly agreeing’ that they would take the vaccine. Rates are even lower in Russia, Poland, Hungary and France, where just one in five agreed with the statement, a poll showed in September.

When combined with those who ‘somewhat agree’ they would take a vaccine, the rates rose to over half in all those countries.
___________________

Credit: The Daily Mail