Vaccine mandates have been divisive ever since the first rollout two centuries ago, and they continue to split public opinion today as governments scramble to inoculate populations against coronavirus.
With Austria set to become the first country in Europe to impose COVID-19 vaccinations on Friday, AFP looks at vaccine orders in Europe -- and whether they work:
In Austria, those who do not become vaccinated against COVID under the new mandate will face a 600-euro ($670) fine.
Tens of thousands have taken to the streets almost weekly to protest the decision.
Frequently Asked Questions
A vaccine works by mimicking a natural infection. A vaccine not only induces immune response to protect people from any future COVID-19 infection, but also helps quickly build herd immunity to put an end to the pandemic. Herd immunity occurs when a sufficient percentage of a population becomes immune to a disease, making the spread of disease from person to person unlikely. The good news is that SARS-CoV-2 virus has been fairly stable, which increases the viability of a vaccine.
There are broadly four types of vaccine — one, a vaccine based on the whole virus (this could be either inactivated, or an attenuated [weakened] virus vaccine); two, a non-replicating viral vector vaccine that uses a benign virus as vector that carries the antigen of SARS-CoV; three, nucleic-acid vaccines that have genetic material like DNA and RNA of antigens like spike protein given to a person, helping human cells decode genetic material and produce the vaccine; and four, protein subunit vaccine wherein the recombinant proteins of SARS-COV-2 along with an adjuvant (booster) is given as a vaccine.
Vaccine development is a long, complex process. Unlike drugs that are given to people with a diseased, vaccines are given to healthy people and also vulnerable sections such as children, pregnant women and the elderly. So rigorous tests are compulsory. History says that the fastest time it took to develop a vaccine is five years, but it usually takes double or sometimes triple that time.
In other countries, the authorities have flip-flopped on whether to impose a direct mandate or implement alternative measures to penalise the unjabbed.
But doctor and philosopher Anne-Marie Moulin, who advises vaccine policy in France, said hesitant governments can give the impression, true or not, of political motivations -- not just health concerns -- behind the measures.
And in France, even though no direct mandate exists, many have accused their government of infringing on their civil liberties.
There is evidence, meanwhile, that mandates may end up driving people away from jabs, while leaving people the choice can have positive results.
In September, when UK media reported the government was considering requiring health workers to get COVID-19 jabs, physician and vaccine expert Peter English warned that taking choice away could stimulate backlash.
"Most health care workers already choose to be vaccinated... and, as long as they are given the time required to get vaccinated, they do so," he commented at the time.
He said some of those not yet jabbed were hesitant, while very few held "irrational, faith-like anti-vaccine beliefs".
"You are unlikely... to shift the latter's beliefs, but you may be able to persuade the hesitant," he said, adding that a mandate risked hardening the undecided against jabs.
By some estimates, Sweden has managed to vaccinate over 90 percent of its population with no mandate.
And other Scandinavian countries also report high levels of vaccination without imposing consequences.
In France, jabs against COVID are not obligatory, but the state has imposed a compulsory vaccination pass to access most social activities, thus punishing the unvaccinated by barring them from places like restaurants and museums.
Historian Laurent-Henri Vignaud insisted, however, it was very different from a law requiring vaccination.
"In one case you're saying, 'the protective state is... telling you what you must do'," he told AFP of the option that was rejected.
"And in the other you're saying, 'do what you want, but your choice will be the difference between whether you can participate fully in social activities or not'."
Smallpox history lesson
Sweden was one of the first countries to impose a vaccine mandate in the early 19th century to contain a deadly smallpox outbreak.
Europe had for decades been ravaged by the highly contagious disease, which causes fever and a horrifying skin rash, and can lead to death.
Sweden lost as many as 300,000 lives between 1750 and 1800, before the world's first smallpox vaccine became widespread.
The Nordic nation imposed vaccines in 1816, and by the end of that century had become the first country to eradicate the disease.
The British government followed suit in 1853 with the "United Kingdom Vaccination Act", which required parents to vaccinate babies against smallpox within their first three months or face fines.
Across the Channel, French soldiers fighting the Franco-Prussian war of 1870 suffered huge losses due to smallpox and were ultimately defeated by their better-vaccinated adversaries.
But it would still take decades of parliamentary arguing for France to decide to make smallpox jabs mandatory for babies, in the country's first such law, in 1902.
In the United Kingdom, meanwhile, a major shift in public opinion had caused the government to backpedal and pass a new law in 1898 that allowed people to refuse jabs for moral reasons.
Protests against jabs, which were not as consistently safe or effective as today's vaccines, had begun as soon as Britain's mandate was imposed decades earlier.
The government eventually relented after thousands of parents were prosecuted for refusing the jab as part of a peaceful but hugely popular movement in the city of Leicester.
"By the time France opted to impose vaccination at the start of the 20th century, England had abandoned the idea and never went back," Moulin told AFP.
Today, Sweden and the United Kingdom have some of the laxest vaccine requirements in Europe.