Recent outbreaks of measles, a highly contagious viral disease, have occurred everywhere from Orthodox Jewish communities in New York, to south-west Melbourne, to Disneyland in LA.
In the first three months of this year, more than 100,000 measles cases were reported worldwide — up nearly 300 per cent from the same period last year, according to the World Health Organisation.
Although measles is more common in places where children don't have access to good health services, it's the outbreaks in countries where the disease had been eliminated that have public health officials worried.
Public health expert James Colgrove tells RN's Rear Vision that, despite a safe and effective measles vaccination, there's a "hesitancy" among some parents towards vaccination.
The opposition to vaccination is not new.
As historian of medicine Elena Conis explains, "as long as there has been vaccination, there has been resistance".
Cow pus for the children
In 1798 English physician Edward Jenner noticed that milkmaids, who frequently caught cowpox disease, were protected from the vastly more severe smallpox outbreaks.
After experimenting on the youngest members of his family, he began to deliberately infect people with cowpox, hoping to give them immunity from smallpox.
The first vaccine was born.
Jenner used a scraping method with a small knife, used to make abrasions on the skin.
He would apply pus from diseased cows onto the open sore and then cover it up with dressing.
It was a method not without its sceptics: the earliest known anti-vaccination advocates.
"You can imagine the reaction of some people to the idea that healthy people should have deliberately introduced into their body animal matter from diseased cows," Professor Colgrove says.
"The bodily invasiveness and also the visceral reaction against cowpox ... in part gave rise to early opposition to vaccination."
It was a sometimes fatal exercise, and public excitement for it was minimal, especially as its scientific reasoning was still a few decades off, says historian Ella Stewart-Peters.
"There was no real logical junction there between why you would vaccinate a child and why it would prevent a disease," she says.
In 1853, some six decades after Jenner's first experiments, authorities began to pay serious attention to Jenner's findings and the British government passed the first of a series of laws making vaccination compulsory.
There were fines and even imprisonment for those who refused, which activated the vaccination sceptics of decades earlier.
Anti-vaccination societies immediately sprang up, people rioted and opposition spread internationally.
"It was tied quite closely to the anti-vivisection movement — the people who protested against the idea of animals being vivisected in medical science," Dr Stewart-Peters says.
The temperance movement also drove the anti-vaccination sentiment, maintaining that disease could be cured, not with medicine, but "through good diet, [and] abstaining from meat and from alcohol", she says.
Free to choose
When the next vaccines were developed between the 1920s and 40s, public health officials knew they needed to challenge the public's hostility towards vaccines that had reached English-speaking countries around the world.
In the UK vaccines were made non-compulsory. Uptake was also helped by the proliferation of the syringe — an easier sell than the skin abrasion technique.
But arguably the greatest international public relations exercise for the vaccine came in the 1950s, when doctors invented a defence against the devastating disease, polio.
"[It] was really a public sensation," Professor Colgrove says. "This was the high-water mark for the public acclaim of vaccination."
"In the 50s, when polio was so feared, people weren't resisting the vaccine. Everybody wanted to get the vaccine," he says.
But when in the 1960s vaccines against childhood illnesses like measles were invented, people were less interested.
"They were used to living with measles. They did not see it or think of it as a serious disease," Professor Conis says.
When US public health officials reintroduced compulsory vaccination for school children, enthusiasm waned further.
Professor Conis says it affronted those members of the public "who don't believe that the government should be in the business of dictating what they should do with their bodies or telling them the healthcare decisions they need to make".
The "age-old 19th-century objections to mandatory vaccination" had resurfaced, she says.
Anti-vaccinations reborn
In the 1980s, global anti-vaccination activism boomed in the wake of controversy around the pertussis, or whooping cough, shot.
"There had been some very inconclusive research published, but speculation that in rare cases the pertussis vaccine might cause inflammation of the brain, seizures and in some cases even brain damage," Professor Colgrove says.
New groups sprang up in the US and beyond, comprising of "generally well-educated and middle-class parents who believed their children had been harmed by the pertussis vaccine", he says.
"They formed an organisation, they contacted congressional representatives and were quite savvy about spreading the message of their concerns."
Then, in 1998, British medical journal The Lancet published a paper by gastroenterologist Andrew Wakefield that became an international sensation.
In the paper, Dr Wakefield and his co-authors speculated that there was a connection between the measles, mumps and rubella (MMR) vaccine, and the development of autism.
"One of the terrible and ironic things about this paper is that it had so little scientific merit, just in terms of the methodology and the design … it was not a control trial," Professor Colegrove says.
The research was fraught in other ways, too.
"It eventually turned out that the investigator Andrew Wakefield had a conflict of interest, which he did not disclose at the time of the paper," he says.
"And then it later came out the study was based on fraudulent data."
But by the time Dr Wakefield was stripped of his licence to practise medicine, the theory had already spread widely.
"The idea that somehow the MMR vaccine was related to autism became cemented in the public's imagination, where it unfortunately remains to this day," Professor Colegrove says.
Professor Conis says it's simply a case of history repeating.
"The current debate that we are having about measles vaccination is a repeat of these historical moments in which we found ourselves," she says.
"The public is pushing back for the same old reasons they have voiced for 200 years of vaccination."
Nonetheless, she says we have plenty to celebrate.
"We have never vaccinated as many children or individuals against as many infections as we do now," Professor Conis says.
"I think by focusing on these ... small numbers of across-the-board resistors, we fail to realise how much we have achieved."
