Vaccines and health data at the Danish National Archives
Vaccines and health data at the Danish National Archives
Danes have been vaccinated since 1810, and the Danish National Archives documents this entire development. From handwritten records to digital registries, the latest vaccination data has just been submitted.
Health and disease preserved in the archives
During the autumn and winter months, many Danes receive seasonal vaccines.
The National Archives holds kilometres of records and data about health and diseases—also about which diseases Danes have been vaccinated against, ever since the first vaccination policy in 1810.
An injection of vaccine history
Vaccination was one of the most significant advances in public health in the 19th century. The first vaccine ever developed was against smallpox.
The British physician Edward Jenner conducted successful trials with a vaccine against cowpox as early as 1796. His hypothesis was that inoculation with pus from cowpox sores would protect people against smallpox. This was proven when he successfully vaccinated his gardener’s 8-year-old son, James.
By the late 18th century, it was observed that cattle farmers and others exposed to cowpox did not contract smallpox. The vaccine’s bovine origins can be seen in its name. The word ‘vaccine’ comes from the Latin word for cowpox: Vaccinia. As an anecdote, Jenner’s cow Blossom, which provided the cowpox infection for James’s vaccination, is also preserved: its hide is now displayed at St. George’s Medical School in London.
Almost compulsory vaccination
In 18th-century Denmark, smallpox was one of the most feared diseases. Physicians wanted mandatory smallpox vaccination for all children, but King Frederik VI would not allow it. However, the “Vaccination Decree of 3 April 1810” required everyone to show a vaccination certificate, for example, to start school (from 1814 schooling was mandatory), be confirmed, or marry. So, although vaccination was officially voluntary, in practice it was almost unavoidable.
Through the 20th century, new vaccines were developed as microbiology progressed, including vaccines against yellow fever, measles, whooping cough, polio, and, in the 21st century, against HPV, Ebola, and COVID.
From ledgers to digital registers
Initially, vaccination data was entered in handwritten registers. Today, this information is stored in digital registers, reflecting the digitalisation of the healthcare sector and public administration as a whole.
Statens Serum Institut (SSI) is responsible for preventing and controlling infectious and congenital diseases. One of its tools for monitoring disease occurrence is that physicians and other health professionals are required to report cases of certain diseases to SSI’s databases.
Many of these databases are transferred to the National Archives, which serves as the core historical record of Danish public health: Which diseases have affected us in the past? Which are we still battling? Why does a particular disease spread historically?
Selected health data in the Danish National Archives
Vaccination register from 1812
In the vaccination register from Gangsted-Søvind Parish, you can see a list of those vaccinated and a copy of Frederik VI’s decree on smallpox vaccination.
Tuberculosis
The mycobacteria register traces cases back to 1930.
HIV infection
Reporting of HIV antibody-positive cases documents HIV infections in Denmark, 1990–2005.
Notifiable diseases
Over 50 communicable diseases have been notifiable since 1980.
The Danish Vaccination Register
The latest submission from SSI is the Danish Vaccination Register (DDV). Although established in 2009, it contains records dating back to 1996.
DDV consolidates and stores individual vaccination records, giving both citizens and healthcare professionals an overview of vaccinations. It is used to monitor the real-world effectiveness of vaccines by tracking disease trends over time and also to plan vaccination campaigns such as the childhood vaccination programme.
How does the National Archives manage complex data?
When an IT system is transferred to the National Archives, it is converted into a digital archival copy (an archive version). This must include extracts of the system’s data, a data description, and information on how the data is structured in the archive version.
Many public systems have a complex technical structure and are not designed with archival transfer in mind. They usually consist of hundreds of tables, of which only the ones with long-term historical value are selected for preservation.
Long-term digital archiving
The aim of creating archive versions is to ensure systems remain usable and system-independent for the long term. This means the data does not require specific software to access and must be preserved in formats future users can read. Detailed documentation and descriptions are essential so that future users can interpret the data correctly. Every archive version is subject to a rigorous quality review to meet these requirements.
This ensures that data will remain accessible, understandable, and valuable even centuries from now.
Documenting societal development
The Danish National Archives collects both paper and digital records—from state agencies, municipal authorities, educational institutions, and key private stakeholders. In this way, the Archives ensures that the development of Danish society can always be documented and that data is available to citizens, researchers, and administrators.