Vaccination against smallpox was one of the first major achievements of modern medicine, stemming from Edward Jenner's experiments in 1796.  Vaccination spread rapidly through Western Europe, and epidemics of this dangerous and disfiguring disease greatly diminished.  But it was not easy to ensure that vaccination was well advertised and easily available, and that the lymph needed for the vaccine was effective and safe.  Although many people wanted vaccination for their children, particularly when an epidemic threatened, the poor had to rely on charitable organizations or, occasionally, the Poor Law authorities, to provide a vaccination service.  Others had to pay their own doctors.  The reform of the English Poor Law in 1834, followed by the Registration Act of 1836, gave England a basis for a public vaccination service, and in 1840 the first Vaccination Act enabled the new Poor Law guardians to set up public vaccination services, usually through their own Poor Law medical officers.  A year later, this service became free.

Vaccination was not compulsory in England until 1853, when the law began to involve the local registrars of births, marriages and deaths.  The registrars gave blank vaccination certificates to parents of newly born children, who had to return them within a specified time, signed by a medical man to indicate a successful vaccination, or face a fine.  Further legislation in 1867 tried to tighten up the law: to force guardians to provide adequate services, to compel doctors to fill in the certificates efficiently, and, in particular, to make guardians prosecute parents who did not have their infants vaccinated.  In spite of all this, there were few prosecutions, many children were not vaccinated, and during the  smallpox epidemic in 1871, over 23,000 people died.  Although vaccination by government-controlled lymph was a fairly safe process, alarm over the small number of deaths of children following vaccination, together with dislike of the Poor Law connections of public vaccination, made many people suspicious of vaccination, and anti-vaccination campaigns were vigorous and well publicized. 

As with other aspects of registration, Scotland was slow to follow England, but then tried to improve on the English model.  The English Vaccination Act of 1840 could not have been applied to Scotland, which at that time had neither substantial Poor Law authorities, nor registrars.  Many highland parishes did not even have a resident doctor, and some small parishes were too poor to pay a Poor Law medical officer.  The Board of Supervision, introduced in Scotland by the Poor Law reforms of 1845 to administer the Poor Law, tried to persuade parishes to provide free vaccination services, with very patchy success.  With the coming of local registrars and registration examiners in 1855, there was at least a machinery for supervising the system, but the first registration examiners were discouraged by what they saw.  Alfred List wrote in his first examiner's report that:

'England enjoys the benefit of repeated Vaccination Acts, which impose a duty upon parents, the neglect of which is punishable; yet poor Scotland has never been deemed worthy of such favourable consideration!  The health of her children is consigned to the care of the Board of Supervision!  Are the lives of her people less valuable than those of the inhabitants of the sister Kingdom?  Or are there circumstances so adverse as to prevent legislation for this sanitary purpose?'

When Scotland did finally get a Vaccination Act in 1863, it was quite different from the English system.  The Royal College of Physicians of Edinburgh and other medical bodies in Scotland successfully lobbied to detach vaccination from the Poor Law, and although the parish authorities paid doctors to vaccinate the very poor, parents could go to any doctor of their choice, and were charged a small fee for vaccination.  As in England, there was a fine for parents who failed to have their infants vaccinated.  The Board of Supervision supplied doctors with lymph, and parish authorities were responsible for prosecuting defaulting parents, but the public did not associate vaccination with the Poor Law. 

Scottish registrars seem to have been diligent in chasing up parents who failed to have their children vaccinated, and the number of prosecutions was small.  Since many registrars were parish schoolmasters, they were probably well aware of the threat of epidemics in the schools, and were in a good position to put pressure on parents.  They sometimes had to sort out arguments between parents and doctors, and on one occasion the Registrar General had to admonish a doctor who refused to hand over a vaccination certificate until the parents paid his fee.  The examiners also took a dim view of doctors who allowed vaccination to be done by midwives in order to save themselves trouble and travelling expenses.

Even though the service was not free for everyone, the Scots seem to have accepted vaccination fairly willingly, though as usual, there were great difficulties in reaching certain sections of the population, such as travelling tinkers and other itinerants.  Some of the highland and island parishes had no doctor, and special efforts had to be made to reach them.  The remote island of St Kilda, its hardy population cut off from the mainland by dangerous waters, remained unvaccinated until efforts were made to reach the population in 1873 after the Free Church minister (one of only two English speakers on the island), implored the Home Office to intervene.  St Kilda, though nominally in the parish of Harris, had no Poor Law arrangements, and its laird, Macleod of Macleod, sent a boat over from Skye with supplies only twice a year.  A naval vessel was diverted to St Kilda carrying a doctor from Skye, 73 vaccinations were carried out, and a lengthy dispute broke out between the laird, the parochial board of Harris, the Board of Supervision, and the Home Office, over who should pay the doctor's expenses.  The Treasury finally authorized the Board of Supervision to pay him, but not as much as he asked.

In spite of all these efforts, there were always people who refused vaccination, sometimes for religious principles, or because they were worried about the possible side-effects.  Doctors could postpone vaccinating a sick baby, but only for two months at a time, and had to pursue the matter until the child was vaccinated.  If a father persistently refused vaccination in spite of warnings from the registrar, he could receive regular fines of £1 a time, or, if he could not pay, 10 days in prison.  One better-off Glasgow citizen wrote to the Registrar General in 1893:

'I have three times been fined in the Glasgow Sheriff Court for not having my boy, now nearly 5 years old, vaccinated . . . The Barony Parochial Board here know that it is not my intention to have any of my children vaccinated, and this not from any religious 'fad' or peculiar view, but simply because I prefer not to take the physical risk involved in the operation.  They deplore, almost as much as I do, the fact of my repeated prosecutions, but say that, so long as my name is returned by the Registrar as a defaulter, they have no option but to prosecute.'

In 1907 the law was amended to permit 'conscientious objection' to vaccination, at a time when the threat from smallpox had greatly diminished.  If a father affirmed before a magistrate that he objected to vaccination because he believed it threatened the health of his child, and paid a fee, he would receive a certificate to take to the registrar and vaccination was not enforced.  This was national legislation, and although some Parliamentarians tried to persuade the government to allow mothers to carry out this procedure, because fathers could not always get time off work, this request was refused.  Only unmarried mothers or widows, or women whose husbands were abroad for a long period, were allowed to object in their own right.

Compulsory vaccination for smallpox was discontinued in the UK in 1948, and the registrars were finally relieved of their duty to log successful vaccinations and conscientious objections.  There was a small outbreak in Glasgow in 1950, but in 1978 the World Health Organisation announced that the smallpox virus had been eradicated globally.