How Bridging Vaccination Gaps Strengthens Public Health
- Bridges M&C team
- Sep 29
- 6 min read
Updated: 5 days ago
Over the past five decades, it is estimated that 154 million lives have been saved through immunisation programmes, the vast majority of them children under the age of five.
Smallpox has been eradicated, polio is close to being eliminated, and diseases such as measles, diphtheria, and pertussis are controlled in countries with high vaccination coverage. Yet, despite these achievements, access to vaccines remains uneven across the globe, and the benefits are still not shared equally.
The COVID-19 pandemic exposed these inequities with startling clarity. High-income countries secured early and abundant supplies of COVID-19 vaccines, while low- and middle-income countries (LMICs) waited an additional 100 days to gain access. This crisis underscored global health experts’ concerns for years, that the place of one’s birth remains a key determinant of whether an individual will survive diseases that vaccines can prevent.
According to Dr David C. Kaslow, who was previously Chief Scientific Officer at Program for Appropriate Technology in Health (PATH) USA, “A formulation in a vial does not become a vaccine until it is injected into the arm of a recipient. The COVID-19 pandemic has shown that it is a whole lot easier to make billions of doses of vials filled with a formulation. However, it is much, much harder to get those doses into the arms of people who might benefit from them.”
These words reflect the paradox at the heart of global vaccination; it is at once the most successful intervention in public health, and yet most affected by inequity.
The global vaccination gap
While vaccination coverage has improved over the decades globally, progress has slowed in recent years. According to estimates from the World Health Organization (WHO), approximately 14.3 million children in 2024 missed out on any one vaccination. These are known as the ‘zero-dose’ children. Millions more are under-immunised, having missed one or more recommended doses.
The latest figures show that global coverage for three doses of the diphtheria-tetanus-pertussis (DTP3) vaccine stands at 85%, and for the first dose of the measles vaccine at 84%, both below the 90% threshold considered necessary for adequate population protection.
These numbers are also below pre-pandemic levels, as COVID-19 disrupted immunisation services worldwide. The consequences are stark: 94% of all infectious disease deaths occur in LMICs, and of those deaths 46% are from diseases for which there is not a registered vaccine. This means, 54% have died from a disease they could have been vaccinated against.
For Dr Kaslow, the challenge lies not only in developing vaccines but also in ensuring that they are integrated into broader health systems. “To make progress, we must integrate vaccines into a broader framework of health system strengthening, not treat them as stand-alone interventions to optimise the benefits,” he stressed. Without robust infrastructure, supply chains, and health workforce capacity, vaccines cannot achieve their full potential, no matter how effective they may be in clinical trials.
Southeast Asia's progress and vulnerabilities
In the Southeast Asian region, countries such as Singapore and Malaysia have some of the highest routine immunisation coverage rates in the world. Malaysia consistently reports over 90% coverage for core childhood vaccines, including DTP3, measles, and hepatitis B, while Singapore maintains near-universal uptake. However, both countries remain vulnerable to diseases for which vaccines are absent, limited, or not widely deployed.
Singapore, for instance, experienced a large Zika outbreak in 2016, with over 323 confirmed cases, and sporadic cases have been reported since. Malaysia, meanwhile, continues to grapple with endemic dengue, reporting tens of thousands of cases annually. Japanese Encephalitis (JE) persists in rural areas, while Hand, Foot and Mouth Disease (HFMD) causes recurrent outbreaks severe enough to trigger temporary school closures and significant economic disruption. Despite strong routine immunisation systems, these gaps in vaccine availability leave populations exposed.
Public confidence in vaccines also shows signs of fragility. A 2022 survey found that only 69% of Malaysians considered vaccines safe and 71% believed them to be effective. While these are still majority figures, they fall short of the levels needed to sustain high uptake and resilience against misinformation.
The cost of neglected tropical diseases
According to Professor Wang Linfa of National University Singapore, “The next pandemic threat will most likely come from zoonotic and vector-borne diseases, which are areas where vaccines remain underdeveloped.”
The neglect of these diseases comes at a high cost. Zika virus not only causes acute illness but has devastating consequences for infants when pregnant women are infected, including microcephaly and other congenital abnormalities. JE remains the leading cause of viral encephalitis in Asia, with case fatality rates as high as 30% and long-term neurological complications in 30 to 50% of survivors.
HFMD, while less fatal, imposes heavy economic burdens. A study from Vietnam estimated that between 2016 and 2017, the
cost for treating HFMD outbreaks in local hospitals was a whopping US$90,761,749 for the total of 94,313 cases. Another study in China revealed the average cost for HFMD outpatients could reach up to 305.2% of the average monthly income.
Nurseries often have to shut down when there is an HFMD outbreak, which means at least one parent cannot go to work and instead stay home to care for the child.
“We cannot wait until an outbreak occurs. Our best defence needs to be improved surveillance, the regular screening of at-risk populations and international sharing of data. And once an outbreak is detected, a rapid response to isolate and contain it is crucial; every day counts," Prof Wang iterated.
Advancing research & innovation
Despite these urgent needs, big pharma have historically focused on mass-market vaccines, such as those for influenza, HPV, or COVID-19, where commercial returns are higher. This is because the standard sequential vaccine development approach which requires developers to proceed step by step, and trial phase by trial phase, often cost billions of US dollars and take 10 or even 15 years to complete.
Due to risks of failure and huge costs involved, big pharma have always been very cautious in their approach to vaccine development, and often find diseases that disproportionately affect LMICs less attractive to invest in. This is where regional innovation and local manufacturing become critical.
One company attempting to address this gap is Sun Biotech, a Singapore-based biotechnology firm established to tackle underserved diseases. From its inception, Sun Biotech focused on tropical and emerging infections that are often overlooked by larger players. “We saw that diseases such as Zika, JE and HFMD were causing real suffering in our region, yet very few companies were developing vaccines for them. That was the gap we wanted to fill,” said Mr Hyun Soo Kim, Chief Executive Officer (CEO) of Sun Biotech.
The company is developing a Zika vaccine prioritising women of childbearing age to prevent Congenital Zika Syndrome. Its fourth-generation JE vaccine is designed to cover emerging genotype 5, which current vaccines do not fully protect against.
For HFMD, Sun Biotech is working on a quadrivalent vaccine combining EV71 with three coxsackie strains, engineered to provide broader protection compared to the monovalent EV71 vaccine which is available in parts of Northeast Asia. By adopting advanced cell culture systems and optimising production processes, the company has reduced projected costs from an estimated US$200 per dose to less than US$2 per dose, a price LMICs can afford. The choice of an inactivated vaccine platform is deliberate. With a long record of safety, inactivated vaccines are suitable for children and pregnant women, the populations most at risk from Zika and HFMD.
Cultural and regulatory considerations are also built into the company’s approach. In Indonesia, where halal certification will be mandatory for vaccines by 2034, Sun Biotech is working to ensure its products meet these requirements, anticipating regulatory needs as well as cultural sensitivities.
Collaboration and regional capacity
Equally important is Sun Biotech’s partnership model. Rather than centralising production, the company focuses on technology transfer and licensing agreements, enabling local partners to manufacture vaccines under their own brands. A technology transfer is the knowledge transfer of any process, together with its documentation and professional expertise, between development and manufacturing, or between manufacturing sites.
Mr Kim explained, “Many Southeast Asia countries have policies that promote local manufacturing, and the COVID-19 pandemic has increased awareness for the need for local manufacturing capacity. Our model is aligned with these policies as licensing our technology enables local manufacturers to produce and register the vaccine locally. Once the technology transfer is complete, the local manufacturer receives the technology and produces it under their own brand.”
In Indonesia, for instance, Sun Biotech has partnered with PT Bio Farma, the government-owned vaccine manufacturer, to produce halal-certified vaccines domestically. This approach not only lowers costs but also strengthens local capacity, ensuring countries are less dependent on external supply chains.
Mr Rajinder Suri, Chief Executive Officer of Developing Countries Vaccine Manufacturers Network (DCVMN) shared, “Collaborations and technology transfers have always played an important role in vaccine manufacturing, even pre-pandemic but the COVID-19 pandemic certainly provided a great stimulus to expedite technology transfers to help make vital vaccines available for billions of people worldwide.”
He added, “One of the biggest advantages of vaccine technology advancement is its power to increase productivity that ultimately improves availability, affordability and accessibility.” Sun Biotech’s model exemplifies this principle.
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