Could vaccine patches pave the road to a measles-free world?
In Ghana, Francis Kokutse considers the potential impact of needle-free immunisation.
- 8 February 2024
- 5 min read
- by Francis Kokutse
At Teshie Community Clinic in Accra, mothers winced, and babies wailed as nurses injected vaccines into chubby arms and thighs. The sight of a hypodermic needle is a dreadful thing for many people, and even health workers aren't always inured to the discomfort of a jab.
Introducing patches in LMICs can be a cost-effective strategy to revitalise measles immunisation programmes with stagnant uptake and reach undervaccinated children.
Senior Staff Nurse Margaret Akpene Tekwei said of her upset patients, "This is what we face daily. and I don't blame them because even we, the nurses, feel the pain when we try to push the needle through the body. It is not easy."
Just a little pinch?
While research has shown that needle fear constitutes a significant barrier to vaccination in children, the ouch factor is not even the major downside to needle-based delivery of vaccines.
Needle-based jabs can be logistically tricky to handle, especially in disadvantaged settings. Often, they need unbroken, end-to-end cold chains; they need well-trained health workers, both to draw up correct dosages and to correctly administer them.
Scientists and public health experts hope that a new technology, vaccine patches – small round stickers pressed to the skin, rough to the touch but not syringe-sharp – could help.
In a new modelling study published late last year in the BMJ Global Health, researchers examined the prospective cost-effectiveness of microarray patches (MAPs) against measles and rubella (MR) in 70 low- and middle-income countries (LMICs). Their findings were encouraging: "Introducing MR-MAPs in LMICs can be a cost-effective strategy to revitalise measles immunisation programmes with stagnant uptake and reach undervaccinated children," the authors conclude.
Patching up immunity gaps
14.3 million children worldwide are estimated to be "zero-dose," or totally unvaccinated. That leaves them at grave risk from the entire gamut of preventable diseases.
Gavi is working hard to help remedy that. With many of the world's unvaccinated children clustered in some of the planet's hardest-to reach places – like geographically remote areas, or conflict zones – new delivery tools could be a huge help.
The most exciting thing about MAPs is that they could enable us to reach the unreached with vaccines, including zero-dose children," said Tiziana Scarnà, a Senior Manager in market shaping at Gavi. "But to get to that point, MAP technology needs investment from the industry."
The sustainable uptake of patches as part of immunisation strategies has the potential to boost equity – the simple-to-use patches are well suited to often underserved populations in more remote or more troubled areas – and could head off 27–37% more measles cases in the ten years from 2030 to 2040, compared to needle-only roll-outs. That's an especially heartening prospect amid news that measles deaths are spiking globally.
Co-author of the study, Dr Han Fu, a Research Fellow in the Department of Infectious Disease Epidemiology and Dynamics at the London School of Hygiene & Tropical Medicine (LSHTM) told VaccinesWork in an email exchange that, although patches are still at an early stage of clinical development, the work demonstrates the major potential health and economic impacts of introducing patches in country immunisation programmes.
MAPs for Africa
"Policymakers could take the study results as a foundation for discussing the potential use cases of MR-MAPs, and plan for the future application of the innovation. Our study is particularly [relevant for] Africa, where many countries are affected by high measles burden and stagnant growth of vaccine coverage," she said, adding that, "the introduction of MR-MAPs alongside needle-based vaccines in immunisation programmes would help improve the uptake and could ultimately save more lives."
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Fu said the patches are an innovation with great potential to address current barriers to vaccine implementation. Unlike traditional needle-based vaccination, MAPs are operable by minimally trained staff, which may unblock workforce constraints for reaching zero-dose children and under-immunised populations, she added.
Moreover, unlike traditional vaccines, the patch vaccines can also be removed from the cold chain for last-mile transportation, potentially easing delivery to tricky regions.
"The single-dose design for MAPs can reduce the wastage of unused vaccines and enhance the convenience of application. Some needle and syringe vaccines such as MR require constitution [the dilution process to make vaccines ready to deliver] before administration, and reconstituted doses that are not used within six hours are discarded," Fu said.
Dr Kwasi Boahene, Director of Health Systems for PharmAccess, a non-profit focused on democratising access to healthcare in sub-Saharan Africa, agreed that MAPs have the potential to transform the way vaccines are delivered in Africa.
"They are developed to overcome many challenges faced by traditional vaccine delivery. For example, MAPs have the potential to reduce cold chain burdens, and eliminate the risk of needlestick injuries often associated with needle and syringe delivery," said Boahene, adding that they could also enable delivery by lesser-trained health workers, and reduce implementation cost.
Back to the present
Not far from the Teshie Community Clinic is the Family Health Medical School, which is attached to the Family Health Hospital.
Charles Fleischer-Djoleto, Dean of the Medical School, told VaccinesWork that only about 284 children undergo vaccination at the hospital each year, which falls short of the estimated vaccine-eligible cohort here – 584 children per year.
Our study is particularly [relevant for] Africa, where many countries are affected by high measles burden and stagnant growth of vaccine coverage. The introduction of MR-MAPs alongside needle-based vaccines in immunisation programmes would help improve the uptake and could ultimately save more lives.”
- Dr Han Fu, LSHTM
In 2023, a rash of vaccine shortages complicated the challenge facing an immunisation system already impacted by COVID-19. Early last year, a measles outbreak struck the country's north, underscoring the risks of waning immunisation coverage.
But even when vaccines are available, Fleischer-Djoleto says, spurring demand for vaccination is difficult here. "Mothers come for vaccination, then refuse to return for subsequent doses. They don't return missed calls, and the fact that the hospital does not work weekends, affects attendance at the clinic."
The reasons for that are hard to diagnose with certainty, but lowering barriers – of both anxiety and convenience – would almost certainly help. It's a tantalising prospect. "The Research Unit of Family Health University College would be honoured to create the awareness, participate in any research and project to introduce MAPS in Ghana," Fleischer-Djoleto volunteered.
Boahene notes that Ghana is eligible for Gavi's MAPs vaccine trials and delivery, adding that, in a study carried that assessed the usability and acceptability of MAPs, all health care workers were able to apply them correctly.
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