Ellen Phiddian
Cosmos science journalist
Last year, mpox spread across the world for the first time, causing at least 85,000 cases worldwide.
The virus’ spread (mostly among younger men who have sex with men) triggered a vaccine rollout with readily available vaccines.
Mpox vaccines are similar to the first modern vaccine: the smallpox vaccine. So similar, in fact, that a new study has found that old-school smallpox vaccination provides some protection against mpox.
The study, published in Cell Host & Microbe, looked at the “memory” cells (T-cells) in blood donors to see if those who were old enough to be vaccinated against smallpox were protected from mpox.
“Our study shows that this is the case, which implies that the memory cells are very long-lived and that they can recognise closely related viruses such as the mpox virus and provide overlapping, or cross-reactive immunity,” says corresponding author Dr Marcus Buggert, a researcher at the Center for Infectious Medicine, at the Karolinska medical university in Sweden.
The researchers looked at blood from 105 healthy Swedish donors. Smallpox vaccination was compulsory in Sweden until 1976, when the program was ended because the disease was nearly eradicated (it was formally declared eradicated worldwide in 1980).
They found that blood from people born before 1976 had a significantly stronger immune response to both smallpox and mpox.
This means that their resistance to smallpox has lasted for decades, and that the vaccine can provide protection against other similar viruses.
Mpox vaccinations are available for at-risk groups in Australia.