Poor vaccine coverage adding to heightened SA measles outbreak risk, experts say
A recently published survey found that only 76.8% of children surveyed have received all their required childhood vaccines. Elri Voigt unpacks the survey findings and asks whether a recent measles outbreak in Gauteng may be a harbinger of worse outbreaks to come.
Some local experts fear that small measles outbreaks recently reported in Gauteng may be precursors to much larger outbreaks. This comes against the backdrop of recently released survey findings that confirm that South Africa’s vaccination rates were falling short, even prior to the Covid-19 pandemic.
The pandemic-related hard lockdown disrupted routine health services and saw, among other disruptions, a decline in children receiving their scheduled life-saving vaccines. The National Department of Health embarked on a catch-up drive in late 2020 and early 2021 in 12 districts with the aim of finding and vaccinating children who have missed their immunisations. In 2021, Spotlight reported that only some of the districts had met their catch-up targets.
Spotlight asked the National Department of Health for new data on the catch-up drive and its further catch-up plans. Receipt of the questions was acknowledged, but no response was received by the time of publication. Health minister Dr Joe Phaahla referred to some data on progress in a recent response to a parliamentary question that can be read here.
According to Dr Haroon Saloojee, Professor in the Division of Community Paediatrics at Wits and a member of the ministerial National Advisory Group on Immunisation (Nagi), the impression he has is that the country’s immunisation rates are back to what they were pre-Covid-19. This is based on data he has seen in his capacity as a member of Nagi.
However, the return to pre-Covid-19 levels does not mean childhood immunisation coverage is at the level it should be. Saloojee tells Spotlight that despite the catch-up, South Africa’s immunisation coverage remains sub-optimal, is lower than the target of 90% coverage, and compares poorly to many other African countries.
He adds that immunisation coverage is higher for vaccines that are scheduled to be given at earlier ages.
Results from the Expanded Programme on Immunisation (EPI) National Coverage survey, conducted in 2019 and published recently found that 83.9% of children surveyed had received all the basic vaccinations from birth up until one year of age (this means they have received all the required doses up to the measle 1 dose). The survey was commissioned by the Department of Health and conducted by the Medical Research Council.
Only about 77% (76.8%) of children surveyed had received all 14 age-appropriate vaccines from birth to 18 months. The province with the highest coverage was the Northern Cape, with 81.6%, followed by Gauteng at 81.4%. Limpopo has the lowest coverage at 70.5%.
Coverage varied by district, ranging from 53% to 100% between the 52 districts. The poorest performing district was Pixley ka Seme in the Northern Cape with only 53% coverage followed by OR Tambo in the Eastern Cape with 54%, Capricorn in Limpopo with 62%, Fezile Dabi in the Free State with 63%, and iLembe in KwaZulu-Natal with 64%.
All districts, with the sole exception of John Taolo Gaetsewe in the Northern Cape, failed to reach the target of 91% of children fully vaccinated. And only seven districts managed to achieve the national target of 90% of children fully vaccinated under one year of age.
The survey also found that 4.3% of children were completely unvaccinated. “The number of unvaccinated children was > 5% in 17 districts, and > 10% in four districts, namely Capricorn, iLembe, Thabo Mofutsanyane and ZF Mgcawu,” the survey states. In the majority of districts, 34 out of 52, coverage estimates from the survey (based only on children with vaccination cards) were higher than those reported in the District Health Information System (DHIS) used by health departments. The survey report suggests this is because DHIS estimates don’t accurately capture vaccines administered in the private sector.
Dr Sufang Guo, Chief of the Health and Nutrition Programme for Unicef in South Africa, tells Spotlight that overall estimates for South Africa sit at around 80 to 90% but it varies according to vaccine type and district and economic groups, with many districts not achieving the target of 90% immunisation coverage for all vaccines. Unicef and the WHO also recently published estimates for each country’s immunisation coverage.
She notes with concern that the country has many zero-dose children, meaning children that have not even received their first dose of diphtheria, tetanus, and pertussis vaccine.
While coverage estimates vary slightly between the DHIS and the EPI survey, the conclusion is clear — South Africa is not meeting its targets for the coverage of life-saving childhood vaccines.
Professor Susan Goldstein, a public health specialist and Deputy Director of Priceless (a unit of the South African Medical Research Council) says the situation is shocking.
“There is no good reason for us to not have those very high immunisation rates. It’s shocking, actually, and so I think it is about governance, leadership, accountability. We really need to be pushing those things to make sure that we can protect our children as much as possible,” she says.
Goldstein is concerned about the unequal coverage in many districts as highlighted in the EPI survey. She adds that due to the effect of Covid-19, many children are malnourished leaving them at risk for severe complications or even death if they contract vaccine-preventable diseases like measles.
The effect of low immunisation coverage has already been seen this year when the National Institute for Communicable Diseases (NICD) notified the public of a measles outbreak in Gauteng. While the outbreak has not been large, it is a worrying sign.
Guo says that a measles outbreak is an early indication that there are gaps in the country’s immunisation coverage as insufficient measles vaccine coverage is the major reason for outbreaks of the disease. 95% coverage for measles is needed to achieve herd immunity — a target South Africa has not reached.
“The measles outbreak in Gauteng is a worrying sign of a heightened risk for the spread of vaccine-preventable diseases and could trigger a large outbreak, particularly of measles, affecting many children,” she says.
Dr Kerrigan McCarthy, a pathologist in the Centre for Vaccines and Immunology at the NICD tells Spotlight there have been a number of sporadic measles cases so far this year, and one isolated outbreak in the South-Western part of Tshwane in Gauteng. The outbreak, to date, has been isolated to four epidemiologically linked cases and one or two sporadic cases in the northern part of Tshwane that did not have any epidemiological linkage. The Gauteng Department of Health has since conducted a measles health promotion and vaccination campaign in the areas.
She explains that measles is highly contagious but the vaccine is universally effective. But because coverage for the measles vaccine is not where it should be, outbreaks can occur. She says that if, for example, about a million children are born in the country each year and the country’s measles coverage is only 75%, then about 250,000 children (25%) are not protected against measles. This adds up each year, resulting in an increasingly large cohort of children who haven’t been vaccinated against measles, which reduces the resilience of the community when measles is introduced.
Risk of larger measles outbreak
According to McCarthy, “we are sitting on the cusp of a very large measles outbreak”.
“We are watching with very beady eyes to make sure that all sporadic cases of measles are properly investigated, and then there’s what we call ring vaccination of under-five [year old] children around those cases to prevent onward transmission,” she says.
McCarthy says it’s never too late to vaccinate, so even if a child has missed their measles vaccination date the vaccine is safe to administer at any age and adults can also receive the vaccine.
Saloojee agrees that the country is on its way to another large measles outbreak, which he says should come as no surprise to anyone. He adds that Covid-19’s disruption of immunisation coverage is not the culprit.
“It’s because of poor routine vaccine coverage. Our measles coverage rate has remained stubbornly low at around 80% for at least the past three decades. Covid-19 affected vaccine access but cannot be blamed for ongoing low vaccine coverage,” he says.
Routine vaccination vs mass vaccination campaigns
Saloojee says that in order to combat a large outbreak measles vaccine coverage needs to be improved, ideally by improving routine vaccination coverage but at this point, a mass measles vaccination campaign is more likely to happen.
He speaks about how in the late 1990s, South Africa embarked on a mass immunisation campaign for measles, which targeted 14 million children. After this, measles cases dropped significantly because the campaign raised vaccine coverage. But because the routine immunisation coverage did not improve, another measles outbreak occurred a few years later. This, according to Saloojee, started a cycle of mass immunisation campaigns being required every few years following a measles outbreak, all because the routine childhood immunisation coverage was not where it should be.
These mass immunisation campaigns are not ideal, he says, as it paralyses other healthcare services because resources have to be focused on finding and vaccinating children, meaning other healthcare users suffer. It is also very costly.
The measles cases seen in Gauteng are “little sparks” that for Saloojee signals a bigger outbreak is almost certain. And the only way to respond or prevent it is another mass immunisation campaign. “What we really should be doing is getting our routine coverage up, that’s the real strategy to prevent measles but I’m afraid we’re going to have to resort to another mass immunisation campaign,” he says.
Reasons for low immunisation coverage
Saloojee says that the overarching reason for sub-optimal immunisation coverage is a dysfunctional health system and only a small percentage of poor coverage can be attributed to vaccine hesitancy.
He explains that there are a variety of reasons that children are not vaccinated when they should be. These include vaccine stockouts at clinics, which may be due to provinces not purchasing vaccines or not distributing them evenly, or clinics not managing vaccine stock adequately.
He says that short operating hours or overly busy clinics can also be blamed. Healthcare workers may also miss opportunities to vaccinate children who present at clinics for treatment of other illnesses.
The EPI survey found that the top reason for missed doses across all vaccines was vaccines being out of stock. It also found that a significant proportion of children missed doses because their primary caregivers did not know they were due for vaccines.
Guo tells Spotlight there needs to be sustained attention to the National Immunisation Programme. Without it, she says, hard-fought gains in child immunisation can easily be lost. DM/MC
This article was produced by Spotlight – health journalism in the public interest.