Childhood immunisation programmes have saved millions of lives and prevented much suffering, but have lost momentum over the past decade or so, writes Elri Voigt in Spotlight, who unpacks the available data in South Africa and how immunisation efforts could be revitalised.
Polio used to be one of the most feared diseases in the world, but an effective vaccine in the 1950s changed everything, and today, most countries are considered polio-free, with the exception of two regions in Afghanistan and Pakistan, said vaccine expert Professor Shabir Madhi, Dean of the Faculty of Health Sciences at Wits University.
This victory, along with the global eradication of smallpox, is testament to the effectiveness of immunising children against illnesses. In fact, Madhi said immunisation was “considered to be one of the most cost-effective health interventions”, second only to access to potable water.
For every $1 invested in immunisation, the return on investment is around $20, said Madhi, citing a 2021 study.
The reason, he added, was that when you’re vaccinating children and increasingly, adolescents and adults, you are not only protecting against disease, but also improving longevity, cognitive function, and the likelihood of people becoming productive members of society.
The WHO estimates that globally between 3.5m to 5m lives are saved because of vaccines every year.
What vaccines do children get in SA?
In South Africa’s public health sector, children are immunised against 12 diseases – including both viral and bacterial ones: polio, hepatitis B, rotavirus, tetanus and diphtheria, pertussis, haemophilus influenza B, pneumococcus, measles, mumps, and rubella. They are also vaccinated against TB, but the protection provided by this eventually fades.
For most of the diseases we vaccinate against, Madhi said, the highest burden was in the first one to two years of life.
If the national guidelines are followed, by the time a child is 18-months-old, they are considered fully vaccinated against those 12 diseases, with the option of receiving some boosters. These translate to 14 vaccine doses between birth and 18 months.
In the private sector, children are often given additional vaccines, like those for chicken pox and hepatitis A.
Then there are also several vaccines recommended for pregnant women – to protect them from illness and providing antibodies that can be passed to their babies to protect them in the first few weeks of life.
The government is currently considering whether or not to start providing a vaccine given to pregnant women that protects their babies from RSV, the single most important cause of hospitalisation as well as the dominant cause of lower respiratory tract infections children.
How are immunisation programmes measured?
Measuring the performance of childhood immunisation programmes is not a simple matter, because children receive several vaccines, and multiple doses of some vaccines, all over a period of around 18 months.
Madhi said the general benchmark internationally is the percentage of children who have received all three doses of the DTP vaccine – the combination jab against Diphtheria, Tetanus and Pertussis (sometimes referred to as DTP3). The first and second doses of the measles vaccine are also commonly used to measure how well immunisation programmes are doing – MCV1 and MCV2.
In South Africa, children get four doses of the Hexavalent vaccine, a six-in-one combination against diphtheria, tetanus, pertussis, polio, Haemophilus influenzae type b and hepatitis b in the first two years of life.
This is our benchmark instead of DTP3, and is referred to as HEXA4. In this country, by the time a child is 18-months-old, they should have received four doses of the Hexavalent vaccine, and two doses of the measles vaccine.
The WHO’s target coverage for DTP3, or HEXA4 in the case of South Africa, is 90% or higher. For MCV2 it is 95% or higher. The National Department of Health says the target coverage rate for all childhood vaccines by 12 months is 90%.
Global trends
A study published in The Lancet in July looked at immunisation data between 1980 and 2023, noting two trends on a global scale. The first was that between 1980 and 2023 global coverage of the key vaccines against many childhood diseases nearly doubled.
But these long-term trends don’t give the full picture, because coverage gains slowed between 2010 and 2019 in several countries, including some high-income countries. The Covid-19 pandemic worsened the problem, with sharp declines in coverage, which has still not returned to pre-Covid levels.
Additionally, the WHO/Unicef joint estimates of national immunisation coverage (WUENIC) for 2024 found that globally, some progress has been made in several countries compared with the year before, but coverage is still far from where it should be.
“Compared with 2023, around 171 000 more children received at least one vaccine, and one million more completed the full three-dose DTP series. While the gains are modest, they signal continued progress by countries working to protect children, even amid growing challenges,” the WHO said in a statement.
However, around 20m infants missed at least one dose of a DTP-containing vaccine in 2024, and around 14.3m children never received a single dose of any vaccine.
From improvement to stagnation in SA
South Africa’s Expanded Programme on Immunisation (EPI) was only introduced in 1994, said Madhi. Since then, there have been massive improvements in vaccine coverage. In fact, this country largely led the introduction of new, life-saving vaccines on the African continent.
The bad news is that over the past 10 to 15 years, these gains have stagnated, and current vaccine coverage is far from satisfactory, Madhi said. We hover at just under 75% for DTP3 and about 82% for the measles second dose, according to the latest WUENIC data, far below the WHO targets of 90% and 95% for these two indicators.
Government mostly uses administrative data to measure immunisation coverage.
Essentially, the National Department of Health looks at the number of vaccines distributed to healthcare facilities countrywide and then uses Census SA data to get an estimate of how many children have been born. Using those two parameters, it then estimates vaccine coverage.
However, Madhi warned, these types of data have some limitations. To do this properly, you need an accurate denominator and confirmation of whether all vaccines issued to facilities are actually being used. At best, Madhi said the current administrative data are a “crude measure” of vaccine coverage.
He suggested a better way would be to have an electronic register that links a unique patient identifier (a kind of health ID number) to vaccinations received. This will help adequately map immunisation coverage and ID areas where there might be under-immunisation.
In the absence of such a register, the next best thing is a vaccine coverage survey, although such surveys can be costly to run. South Africa’s last such survey was conducted in 2018-2019. That survey found that only 76.8% of children received all age-appropriate vaccines from birth to 18 months, well below the National Department of Health and WHO’s targets.
Zero-dose children
Concerningly, the survey also noted that 4.3% of children were completely unvaccinated, a group referred to as zero-dose children. According to the 2024 Wuenic report, SA had an estimated 278 000 zero-dose children in 2023.
Apart from an immunisation coverage survey, Madhi said it was difficult to measure how many zero-dose children there really are, because they are, for instance, more likely than other children to have little or no contact with the health system and are thus less likely to be reflected in official health records.
Immunisation coverage, and zero-dose children in particular, is sometimes described as a “canary in a mine” for the healthcare system. As Madhi explained, if there are zero-dose children, it “means your basic primary healthcare is failing”. A big part of primary health is preventative healthcare, and so “if you can’t get something right as basic as making sure children are vaccinated, it means we’ve got massive problems”.
Global decline in vaccine confidence
Since the beginning of the pandemic, there has been an overall decline worldwide in the percentage of people who perceive vaccines as important for children. This is according to an analysis by Unicef based on a 2022 study by the Vaccine Confidence Project.
East and Southern Africa, which saw a drop in vaccine confidence during the peak of the pandemic, mostly rebounded by 2022.
By comparison, South Africa’s rebound was much less dramatic, according to Francine Elvia Ganter Restrepo, a Regional Social and Behaviour Change Specialist for Unicef Eastern and Southern Africa.
This decline in vaccine confidence, she said, “is probably tied to the political discourse around vaccines at the time of the (Covid-19) vaccine rollout and the proliferation of misinformation”.
Why SA children are not getting vaccinated
While vaccine scepticism is a factor, Madhi and other experts are clear that it is not the key driver of South Africa’s low immunisation rates.
“Some of the major challenges are not necessarily reluctance or lack of education, (or) lack of knowledge on the part of parents on the importance of vaccines, but rather the challenges faced in getting their children vaccinated.”
These include structural issues at primary healthcare facilities, like vaccines being out of stock, long queues, and clinics often not being open over weekends, causing parents to become disillusioned with the system. Travel to and from clinics to get all the various jabs is also unaffordable for some.
Madhi said children are more likely to not be vaccinated when they have a teenage mother, or a mother who has not received more than a primary school level education and lives in a rural setting.
So what do we do?
For Madhi, the first place to start to address South Africa’s stagnating immunisation rates is to have “robust systems in place” to track vaccine coverage. “You can’t fix the problem until you’re able to measure the problem. And right now, we’re not in a position to adequately measure the problem in real time to then develop strategic interventions,” he said.
He suggested establishing an electronic vaccine registry, much like what was in place during the Covid-19 vaccination campaigns. This registry should have every healthcare facility that offers vaccinations connected to it, and data on the actual vaccines administered can be upload by nurses – hopefully replacing the paper-based systems still widely in use. For this to work, there must be robust data systems in place with unique patient identifiers.
Having access to these data in real time would let us keep an eye on districts and sub districts that are underperforming, said Madhi, and help identify why targets aren’t being reached, for example by linking lower vaccination rates to vaccine stockouts.
Once you know why children aren’t getting vaccines, he said, targeted interventions can be developed.
Changes should also be made to the mmunisation strategy, suggested Restrepo. This could include making sure any updates come with money set aside for demand creation and dealing with service delivery challenges.
The coming years
If South Africa remains on its current trajectory, Madhi reckons the likely scenario is that we’ll keep seeing more of the types of outbreaks we’ve seen over the past decade: of measles, diphtheria and whooping cough.
The pandemic and associated disruptions caused an abrupt decline in the number of children getting the vaccines they need, and the push by the National Department of Health to catch up on those missed doses deserves some credit.
But generally, the picture is bleak. The massive progress of the first decade or so after the end of apartheid has given way to stagnation well below the levels that both the WHO and our own Health Department say we need to reach.
It is tempting to blame vaccine scepticism for this stagnation, but as the experts have said, other factors are playing a bigger role in South Africa.
See more from MedicalBrief archives:
WHO, Unicef flag worst decline in childhood immunisations in 30 years
Covid-19 globally causing massive disruption of vaccination of children
How SA’s childhood vaccination system can become great