WEEKEND-VIEWPOINT- Will South Africa disease FMB strategy keep up with the demand.

Compliance does not prevent outbreaks. Immunity does. The distinction matters, because the path from compliance to immunity runs through a chain of dependencies that is easy to overlook in a crisis: immunity depends on timing; timing depends on throughput; throughput depends on execution capacity. Break any link, and standards become theoretical.

The biology is not negotiable. Foot-and-mouth disease vaccines use an inactivated (killed) version of the virus. They are highly effective at preventing clinical disease. But the protection they provide does not last the way many people expect it to.

In cattle, high-potency foot-and-mouth disease vaccines provide strong protection for a defined period – generally shorter in younger animals and longer in repeatedly vaccinated adults. This is why countries managing the disease operate on regular booster schedules rather than one-off injections.

The duration of immunity is not a footnote. It is the foundation on which any vaccination strategy is built.

There is a second biological reality that makes this even more important, and it has nothing to do with the vaccine itself. It has to do with the herd.

Livestock herds are not static populations. Animals leave – they are sold, slaughtered or culled. And new animals arrive, primarily as calves born.

Even if every animal in South Africa’s national herd of roughly 14 million cattle were vaccinated tomorrow, new susceptible animals would begin entering the system immediately. Within a year, millions of calves would have been born without immunity of their own. Within two to three years, a substantial portion of the herd would consist of animals that were not present during the first vaccination campaign.