While South Africa sits without any appropriate vaccines in the middle of the country’s worst-ever foot-and-mouth disease epidemic, many are asking whether vaccines are truly of any benefit anyway. Dr Mark Chimes, the veterinary adviser to and programme manager for animal health and welfare with Milk SA, answers some important questions.
By Lloyd Phillips, senior journalist at African Farming and Landbouweekblad
As South Africa’s remaining stocks of the Botswana Vaccine Institute’s (BVI) foot-and-mouth disease (FMD) vaccine plummeted to zero, many cattle could only be administered a single emergency dose. Would this single dose have provided any protection?
According to the datasheet for Artio Preva, the BVI’s FMD vaccine used in South Africa, a primary course of two doses should be administered three to four weeks apart. This should be followed by a booster vaccination dose every four to six months. In the case of a severe outbreak of FMD such as South Africa is currently experiencing, it is advisable that the initial course of two doses is followed by the booster vaccination dose every four months.
A single dose will probably offer protection for at least six weeks. However, a lower level of antibodies will develop in the vaccinated animal. If a second vaccine dose could be given, the antibody levels would be higher and, therefore, offer better and longer protection.
Giving a single vaccine dose is not ideal in the current outbreak, but it is better than nothing. It helps reduce the number of animals affected and the severity of symptoms. It also reduces the amount of food-and-mouth virus being shed by infected animals. In turn, this should help slow down the spread of FMD. This is evidenced by how fast FMD began spreading once vaccine supplies became constrained from the beginning of December 2025.
Does it help to vaccinate an animal that is already infected with and experiencing the symptoms of FMD?
Vaccinating infected animals is like trying to fix a leaking roof after it has already started raining. It is not ideal. It implies that we wait for herds to become infected and then try to prevent infection with vaccination. As a result, we are constantly chasing after the disease. It is absurd, and stems from rules made in a different era under different circumstances.
Vaccines stimulate immunity in healthy animals against a disease in order to pre-emptively protect the animals against that disease. It takes two to three weeks for antibodies to develop to peak levels after vaccination.
In an already sick animal the immune system is already compromised. Because of this, the animal’s response to the vaccine is not optimal. In addition, the disease will run its course until vaccination-related antibody levels rise to a level where they can start to protect against the virus. However, where herds have been vaccinated in the early stages of an outbreak, the farmers have reported a reduction in the number of sick animals and of the severity of symptoms approximately a week after vaccination.
Also read: FMD | Potentially dangerous vaccines still being smuggled in
There are reports of pre-emptively vaccinated animals still contracting FMD. Are these reports accurate? If yes, is this cause for concern?
I have received several reports of pre-emptively vaccinated herds contracting FMD within six to eight weeks following vaccination. In fact, there are several instances where herds became infected. They were then reactively vaccinated, and they then had another outbreak of FMD within six to 12 weeks of the previous outbreak. This is very concerning.
It is suspected that the cold chain for the FMD vaccines was not always maintained as well as it should have been before vaccinating animals. There are even rumours of vaccines having been frozen – which is incorrect practice – in some cases.
In most cases the initial outbreak of FMD among herds was caused by one SAT strain of South Africa’s SAT1, SAT2 and SAT3 strains, and the second outbreak in these herds was caused by another of the three SAT strains.
Unfortunately, the BVI vaccine used in South Africa in recent years was not specifically developed against these South African strains, causing the present-day outbreaks. If any matching of vaccine strains was made against the South African strains, it would have been made against the South African strains held at the Pirbright Institute (Pirbright) in the United Kingdom. South Africa last supplied latest circulating virus strains to Pirbright in 2011.
For reasons that are unclear, none of the currently circulating viral field strains has been sent to Pirbright. This is despite John Steenhuisen, South Africa’s Minister of Agriculture, having instructed the powers that be to do so last year already.
Do dairy and beef cattle each ideally require FMD vaccines that are specifically tailored for them? And does the same apply to other livestock species susceptible to the disease?
Yes, to a degree. First, we need vaccines that have been matched with the strains of FMD virus currently circulating in South Africa. Second, we need sufficient supplies of these vaccines to be able to administer them as prescribed by the manufacturers. Third, we need FMD vaccines that provide a longer period of protection before a booster vaccination is needed.
We cannot vaccinate the entire national dairy and beef herds every four months. Water-based vaccines are generally cheaper and provide immunity for approximately four months. These are suitable in cases where we vaccinate to slaughter, such as in feedlots.
Oil-based vaccines, on the other hand, are more expensive. However, they generally stimulate a longer immune response for up to nine months and are therefore more suited to vaccinating animals to live, such as in dairy herds and stud animals.
For other species such as sheep, goats and pigs, we need to ensure that there are vaccines registered in South Africa to be used for these species.
Who needs to do what, and by when, to ensure that South Africa’s dairy and beef cattle, and other species, consistently receive sufficient doses of the types of vaccines that can provide the best protection possible for the longest time possible?
South Africa’s Agricultural Research Council (ARC) needs to send samples of the viruses that are causing the current outbreaks to the Pirbright Institute immediately. This will allow vaccine manufacturers to match and produce FMD vaccines for our needs.
Over the past 10 years the ARC’s Onderstepoort Veterinary Institute (OVI) has developed and tested an excellent vaccine matched against our FMD strains, and that gives immunity for nine months. The research was concluded two years ago. However, the OVI does not have the facilities to manufacture the vaccine.
The OVI’s Transboundary Animal Disease facility is in the process of installing vaccine manufacturing equipment that should become operational later this year. This facility was originally planned to supply enough vaccine, namely 200 000 doses a year, to be used in the FMD-controlled zone along the Kruger National Park and along the Mozambique border.
The main facility, which will be able to produce several million doses of vaccine every year, will not be operational before at least 2030. The ARC should therefore supply the vaccine technology to a capable third-party manufacturer to produce the vaccine under licence for South Africa.
The best solution to our current problem has been lying in a fridge at Onderstepoort for the past two years. Why?
Also read: FMD | Vaccine shortage remains a major frustration
What are your views regarding the smuggling in and use of unregistered FMD vaccines in South Africa?
This action by the smugglers and farmers is the direct result of the State Veterinary Services’ lack of securing sufficient supplies of vaccines against FMD. In my opinion, the illegal importation of the Kenya-manufactured FMD vaccines will not stop until the farmers are provided with a legal, effective alternative vaccine.
As much as I understand and sympathise with the reasons why farmers are importing and using the unregistered illegal vaccines, there is a very real danger that the Kenyan vaccines could cause the O or A strains of FMD to become established in South Africa. Until it is proven that these vaccines are safe for use in South Africa, the use thereof carries extreme risk.
The farmers need to realise that an effective vaccine is not a silver bullet that will eradicate FMD. It will only reduce production losses. Despite their own vulnerabilities, strict farm biosecurity and livestock movement controls will still be needed to prevent further spread.
Enquiries: Email Dr Mark Chimes – mark@dairystandard.co.za
Also read:
FMD | Pig industry seeks answers following confirmed and suspected outbreaks
FMD | ‘Tiger heart’ syndrome causing sudden calf deaths
Foot-and-mouth disease (FMD) remains active in seven provinces
