Infectious diseases move quickly, and it can be particularly difficult to predict when and where an emerging infectious disease (EID) outbreak will occur. This poses a challenge for vaccine efficacy trials, which hinge upon active transmission of the target disease in a population to gather meaningful data. As a result, effective disease surveillance is a critical element to support vaccine development.

Early detection of EIDs through global disease surveillance allows researchers to begin developing vaccines as soon as possible and minimise the impact of the disease. Disease surveillance can also inform vaccine trials on where an EID is prevalent so that it can be tested in a relevant population. Because infectious diseases can move quickly, disease surveillance is a key element in vaccine efficacy trials. As a result, understanding current approaches to disease surveillance early alert systems is a helpful tool for advancing EID vaccine development.

Early alert systems

Early alert systems can play a critical role in the quick response to an outbreak. These alerts advise researchers on appropriate site selection and when to initiate vaccine trials. The earlier a disease is detected in a population, the sooner and more efficiently the response can be mobilised.

Early warning strategies involve the use of environmental observations, such as extremely rainy weather, which are associated with outbreaks of a specific disease. However, when a disease is new or uncommon, these measures may have limited effectiveness given there might not be enough information available to fully utilise them. Alternatively, surveillance of agricultural, farm and virology workers, particularly genetic testing when ill workers test negative for most common illnesses in their region, may be particularly effective as these individuals are most likely to be exposed to new and emerging pathogens.1

In an effort to establish early alert systems, the African Center of Excellence for Genomics and Infectious Disease (ACEGID) and the Broad Institute have teamed up for the Sentinel project.2 Based on three pillars – Detect, Connect and Empower – this early warning system is meant to use genomics and information technologies to detect viral threats early and enable public health systems to respond quickly. This is not ACEGID’s only experience with early detection of disease, either, as it has long been committed to studying and responding to infectious disease. For instance, the organisation identified a new yellow fever outbreak in Nigeria in 2018 through the use of real-time microbial metagenomics.3


Wastewater Surveillance

Disease surveillance often depends on individuals seeing a physician when they feel ill. However, medical attention is not always an option for people due to the expense, lack of access and potential distrust of the healthcare system. The question remains: How do we detect the presence of an EID in a population as early as possible?

Wastewater surveillance may offer a compelling answer. It was first widely implemented in the detection of SARS-CoV-2 but now shows great promise with other diseases. Because many pathogens are shed from the body in stool and other waste, analysing wastewater can provide numerous helpful insights regarding the presence of an EID in a community. This method does not depend on individually testing everyone who is ill to get an accurate picture of the prevalence of a particular EID. Additionally, it can detect the presence of a pathogen before patients develop symptoms or if they are asymptomatic carriers of diseases. Such advanced knowledge provides researchers ample time to mobilise vaccine trials while an area is still being impacted by an EID so that as much relevant data can be gathered as possible.


Preparing for the future

While emerging infectious diseases may be difficult to predict, there is much that sponsors and researchers can do now to prepare for new outbreaks that may threaten public health. Methods such as pre-emptive vaccine research, disease surveillance and strategic vaccine trial design can help to fortify vaccine development and the necessary accompanying infrastructure.

To learn more about the use of disease surveillance and reporting in vaccine development, read the whitepaper, ‘Fortifying vaccines: Preparation and prevention against future infectious disease epidemics’.