Lessons from a pandemic

Five years ago, COVID-19 wreaked havoc across the globe. Most countries enacted months-long lockdowns or implemented extensive movement restrictions and testing. Planes were grounded, businesses were shuttered and healthcare systems were stretched to their limits.

Today, we continue to grapple with outbreaks of different types of infectious diseases, many of which are zoonotic and spread from animals to humans, such as mpox, the H5N1 bird flu and ebola. These diseases have been met with varying responses.

“Society’s response to COVID-19 and other infectious disease outbreaks has been a complex mix of successes and failures,” says Professor of Infectious Diseases Laurent Renia at the Lee Kong Chian School of Medicine in NTU.

“The speeds at which diagnostic tools and vaccines were developed and deployed demonstrated the power of collaborative science,” he adds. “But the combination of misinformation, the politicisation of public health and, in some instances, ineffective and poorly explained state responses generated deep societal divisions that severely hampered any chance of an effective overall response.”

Additionally, as healthcare systems dealt with the pandemic, and investors and governments came together in an urgent rush to address COVID-19, deaths from one of the world’s most fatal diseases, tuberculosis (TB), rose.

According to expert estimates, a diversion of resources to COVID-19 from TB efforts could have resulted in 1.4 million additional deaths from the disease between 2020 and 2025.

TB expert Prof Gerhard Grüber from NTU’s School of Biological Sciences believes that TB research has been set back by several years as well.

“Because we are less aware of TB, we are also not so careful anymore,” he adds. 

Building resilience

The impact of COVID-19 underscores the need to develop resilient global health systems that can effectively respond to immediate crises without neglecting long-term health priorities. Beyond the immediate demands of crisis response, we must consider the broader context of industrialisation, climate change and globalisation.

Many pathogens originate from animals, before making the jump to humans. As a result, activities that bring people in close contact with animals may facilitate the transmission of zoonotic diseases to humans.

“Deforestation and climate change have increased human-animal contact, and this raises the risk of new outbreaks,” explains Prof Renia. “Mitigating climate change by reducing emissions, protecting biodiversity and promoting sustainable land use is crucial to minimising these environmental drivers.”

Currently, Prof Renia and his team are investigating the molecular mechanisms behind the spillover of monkey parasites into humans to further mitigate some of these zoonotic risks.

The interconnectedness of human society has also accelerated the spread of infectious diseases, and there is a need for additional measures to complement existing border screening procedures to contain outbreaks.

At the Lee Kong Chian School of Medicine, Asst Prof Keisuke Ejima uses mathematical models to understand the transmission of infectious diseases. One of his recent studies demonstrated that border screening for mpox may not be effective on its own to prevent the virus’ entry into a country due to the disease’s long incubation period and limitations in viral detectability during the pre-symptomatic phase.

While his study highlights the need for science-backed policymaking, Asst Prof Ejima notes that scientific research to inform policy is time-sensitive. But during global health emergencies, sufficient data may not be available to promptly develop, evaluate and implement effective measures. In such cases, a robust global health surveillance system that enables early collection of key clinical and epidemiological data is crucial.

“This includes real-time data sharing between countries, genomic sequencing of viruses and the integration of artificial intelligence-driven predictions with public health decision-making,” he adds.

Innovative treatments

Beyond immediate surveillance and containment, research into the human immune response is also necessary for developing effective long-term interventions against infectious diseases.

Asst Prof Loh Jia Tong from the School of Biological Sciences, who investigates the immune responses of children during illness, believes that a better understanding of their immune systems could go a long way in protecting them from infections.

“Recurrent and severe infections in early life have been shown to impact the lifelong health of individuals,” she explains. “By understanding how the immune system is shaped by early life factors – such as nutrition, antibiotics treatment and infections passed from mother to child during pregnancy – we can help set a child’s immune development on the right trajectory.”

Aside from our bodies’ natural immune systems, pharmaceuticals play a vital role in combating infections. According to Prof Grüber, effective drug development hinges on cultivating a deep understanding of the pathogen before translating that knowledge into novel therapeutic applications.

This translation often requires interdisciplinary collaboration, especially when tackling drug resistance in tricky pathogens like Mycobacterium tuberculosis, which he studies. M. tuberculosis, the cause of TB, results in almost two million deaths worldwide each year. Working with collaborators, he has identified potential drug candidates that inhibit the energy generation pathway in M. tuberculosis, offering a new approach to combat drug-resistant tuberculosis.

However, Prof Grüber acknowledges a major hurdle: access to pharmaceuticals. “There are huge inequalities in terms of access to pharmaceuticals between the rich and the poor,” he says. Addressing this will require coordinated action from multiple stakeholders, including governments and pharmaceutical companies, to drive systemic change in healthcare systems.

Infectious disease outbreaks over the past decade, like COVID-19, have exposed weaknesses in global pandemic preparedness. But they have also provided invaluable lessons. Improvements can be made across infrastructure, education, investment and policy for a more effective response that protects everyone.

“Ultimately, preparing for the next pandemic requires a proactive, science-driven and globally coordinated approach –along with cultivating the next generation of talent to carry this work forward,” says Asst Prof Ejima.