Health Minister Dr Joe Phaahla says doses of the mpox vaccine will be arriving soon for free distribution at clinics – this after South Africa recorded its seventh case, the latest being a 39-year-old man admitted to a private health facility in Cape Town who tested positive last week.
Also last week, Phaahla announced the second mpox fatality, a 38-year-old male who was admitted to an uMgungundlovu hospital and died the same day.
Phaahla said that as soon as donations of the jab arrive, the health department would start to vaccinate four groups of people – men who have sex with men, sex workers, health and lab workers – who have a much higher chance than the general population of contracting the virus, writes Mia Malan for Bhekisisa.
Foster Mohale, Health Department spokesperson, said South Africa was sourcing jabs from Gavi, the Vaccine Alliance and western European countries that have more stock than they need, and who will be donating their extra jabs: however, not all mpox vaccines will work well in South Africa.
He added that results for the first three confirmed cases sequenced a type as clade ll b, the same as the sub-lineage responsible for the multi-country outbreak which began in 2022 and has since spread to more than 100 countries
Smallpox
Because the virus belongs to the same group that causes smallpox, South Africans who were vaccinated against smallpox are already protected against mpox.
The smallpox jab provides about 85% protection against the mpox virus.
But, said Jacqueline Weyer, National Institute for Communicable Diseases’ (NICD) chief medical scientist at its Centre for Emerging Zoonotic Diseases, South Africa stopped smallpox vaccinations in 1980 because the illness had been eradicated, so only people of 45 and older would have received the shots.
People affected with the mpox virus develop a skin rash with blister-like bumps, along with symptoms like headaches, swollen lymph nodes, a sore throat, muscle ache and fever. It’s when the skin looks like this that they’re most contagious, as the fluid in the blisters contain large quantities of the virus.
On average, each person with mpox infects about one other person, Weyer said. (Scientists call this the basic reproduction number, or R0 value, which is a measure of how contagious a disease is; if the value is 1 or more, like for mpox, the disease continues to spread, while it can be thought of as controlled if the value is less than 1.)
The rate of infection, however, increased for a period in 2022 in western Europe, when a global mpox outbreak started. In that year, scientists estimated the R0 value in countries likes Germany and Spain to be between 2.4 and 2.8, meaning each infected person transmitted the virus to more than two other people.
By May 2024, 95 912 cases had been documented from 118 countries.
South Africa recorded five cases in 2022 and none in 2023. But in May this year, mpox cases started to emerge again.
And while there have been seven lab-confirmed cases, of which two patients died, in theory, there could be at least seven other cases if each infected person transmitted the virus to one other. And those cases could also have each infected one more person.
All South African cases are men aged between 30 and 39, from Gauteng, KwaZulu-Natal and now the Western Cape, most identifying as men who have sex with men. and all with weakened immune systems because of (mostly untreated) HIV infection, according to the health department.
Weyer said all of the men were, or have been, hospitalised, which means their disease is severe. One of the reasons why all cases were in their 30s is because that is an age during which people have sex often – but it’s also an age group too young to have been vaccinated against smallpox. This means people in their 30s are at greater risk of contracting the virus.
“Most cases in the other countries were also among men who have sex with men [who tend to] have strong social networks. United States data show that many men who have sex with men and who are later diagnosed with mpox have had multiple sexual partners in a short period, which contributes to a larger scale and faster transmission of the virus.”
It has not been confirmed which brands of vaccines South Africa will receive, but live, attenuated jabs will not work well for the country, because so many people here, particularly people with HIV who are not on treatment, have weakened immune systems.
HIV untreated
According to the Thembisa model, which estimates HIV infections, about one in four of South Africa’s estimated 7.8m people with HIV – about 2m people – are untreated.
Live, attenuated vaccines use the actual (live) virus that causes a disease, but a weakened form of it, to teach someone’s immune system to produce antibodies to protect them against the disease.
In people with very weak immune systems, these jabs may, however, result in serious or fatal infections.
Mpox vaccines, like the one known as ACAM2000, contain live viruses.
The four groups of people the health department plans to vaccinate will amount to hundreds of thousands of people – if they all decide to get vaccinated. This country has more than 340 000 health workers (these include both medical and non-medical staff like cleaners and porters), of whom about 212 000 are healthcare workers (medical staff, such as doctors and nurses).
The public lab service, the National Health Laboratory Service, employs at least 8 000 people and South Africa is estimated to have between 131 00 and 182 00 sex workers; numbers on men who have sex with men in the country are hard to come by.
Meanwhile, getting treatment into the country is the health department’s immediate priority, said Mohale, who expects World Health Organisation-donated shipments of the antiviral drug Tecovirimat, also known as TPOXX, to arrive within days.
Although the drug isn’t registered with the South African Health Products Regulatory Authority (SAHRPA), a special Section 21 approval has been granted to import a small stockpile for possible new cases.
Weyer said most people with mpox don’t need treatment or hospitalisation. “But in severe cases, Tecovirimat is used to stop the virus from replicating in the body, which is why it’s called an antiviral drug.
“The medicine is relatively new, so it’s unregistered in most countries. But steps are under way to secure access to additional doses of treatment [South Africa previously imported doses for some of the already recorded cases] for any further serious cases that might be confirmed here in the coming weeks.”
See more from MedicalBrief archives:
Durban man in hospital for mpox
Mpox case confirmed in Gauteng