If the course of the disease is mild, the blisters dry out after two to three weeks, and the scabs fall off. From that moment on, the patient is no longer contagious. Overall, this process takes about four weeks – small pinpoint scars remain. These are distinctly different from the scar resulting from the smallpox vaccination.
Good to know
The term smallpox includes all diseases caused by the genus of orthopoxviruses. Colloquially, this mostly means the classic smallpox caused by the variola major virus.
Here’s how the smallpox vaccination went
To immunize the body, unvaccinated people received a live vaccine against smallpox based, for example, on the related vaccine virus (cowpox). In this way the immune system was confronted with live smallpox viruses, which however were weakened and therefore less dangerous. This allowed the body to make antibodies against the virus.
The World Health Organization (WHO) has succeeded in eradicating smallpox through strict quarantine regulations and a worldwide vaccination campaign that began in 1967.
Doctors used a special needle or (temporarily) a vaccine gun to vaccinate smallpox:
- Scratching with the crotch needle: In this method, the vaccine was scratched into the skin (scarification) using a two-piece needle. The doctor briefly dipped the needle into the vaccine solution so that some of the liquid could collect between the two needle tips and be injected into the skin. To ensure that the vaccine reached the middle layer of the skin, about 15 controlled points were performed in a circular fashion. Here the vaccinated person had to be careful not to come into contact with the live vaccine and get infected.
- Impfpistol: Using only the high pressure, the vaccine gun injected the vaccine through the skin into the connective tissue. The vaccine was already pre-dosed here, so that a vaccine gun could vaccinate multiple doses in a row.
The bifurcation needle required only a quarter of the vaccine. It was therefore cheaper and easier to use. The eradication of smallpox is therefore partly due to her. The vaccine gun, on the other hand, proved bulky and unreliable by comparison. In order not to slow down the vaccination campaign, the WHO finally used the bifurcation needle.
But even before the WHO vaccination campaign and the development of the vaccine gun and bifurcation needle, smallpox was being vaccinated, although vaccination techniques differed somewhat. For example, a common method was to put a drop of the vaccine on the skin and then scratch it.
Vaccination against smallpox is also possible after contact with the virus
Doctors could not only vaccinate against smallpox as a preventative measure, but also after a person had already come into contact with the virus. However, the so-called incubation vaccination had to be done within a period of four to seven days after the initial contact with the smallpox virus. This was the only way to prevent the outbreak of the disease or at least to mitigate and contain the course of the disease. However, if the rash had already started, incubation vaccination no longer offered any protection. The patient was now highly contagious.
Evidence of the smallpox vaccination: the scar on the upper arm
Most people today can only tell whether or not they were vaccinated against smallpox from the light-colored scar on their upper arm. However, this has nothing to do with using a bifurcation needle or an inoculation gun. Rather, it is a consequence of the vaccination technique and the reaction to vaccination.
At that time, the smallpox vaccine was specifically injected into the skin (intradermally or intracutaneously). As a result, after about a week a controlled infection developed at the vaccination site, a pustule indicating a successful immune reaction. The blister then healed and a scab formed on it. After this scab fell off, a scar was left reminding of the successful smallpox vaccination. From then on, vaccination protection should be guaranteed for around three to five years.
If people had regular contact with smallpox viruses, a booster vaccination could be given after this period, which should offer them protection for up to 30 years. Those who received this second smallpox vaccination now wear two of the oval scars on their upper arms.