Project 1: Optimization of air sampling for the collection and quantification of infectious respiratory viruses.
The accurate determination and quantification of viruses in respiratory droplets is difficult, due to a lack of adequate measurement technology. Consequently, our ability to evaluate the actual threat arising from inhalation or contact with aerosolized viruses is limited. By combining knowledge on virological aspects and fluid dynamics of droplets, improved detection devices will be engineered to allow the rapid identification of "risk traits" in viruses among a vast diversity of animal viruses in nature. In laboratory settings, you will use state-of-the-art in-vitro systems in which viruses can be aerosolized, followed by a pre-determined 'airborne time' and collection with available air samplers. In this system the impact of droplet age, droplet size, evaporation rates and physiological conditions on virus infectivity will be studied for important respiratory viruses such as influenza virus, RSV and corona viruses. In collaboration with collaborators at TU Delft, you will explore and test novel methods for large scale air decontamination. This project will be executed at Erasmus MC under supervision of Dr. Sander Herfst.

Project 2: Routes of transmission and infectivity for respiratory virus families with pandemic potential in humans.
The next pandemic virus will likely be a member of one of four respiratory virus families for which "archetype" members of pandemic origin already circulate in humans. To understand how novel viruses transmit, it is pivotal to understand the potential routes of transmission of these known viruses. In this project we will quantify virus in size-fractionated droplets collected from exhaled breath from hospitalized children. We will further improve protocols which have been developed and successfully used for RSV and HMPV. In addition, as the "clinical" air sampling activities cluster in the winter months, in-vitro stability and infectivity assays will be performed in summers in the laboratory. During these experiments we will specifically look into the impact of the host's immune response on virus replication competence. Sampling will be performed at the Erasmus MC-Sophia in Rotterdam and the Reinier De Graaf Gasthuis in Delft.This project will be executed at Erasmus MC, Department of Viroscience under supervision of Dr. Pieter Fraaij.

Project 3: Optimization of exposure assessment and measurement strategies of airborne viruses.
Information on exposure-response relations is essential for proper risk assessment. For air-transmissible viruses, knowledge on airborne virus concentrations under real-life conditions is mostly lacking. Recently we showed for SARS-CoV-2 that currently available air sampler devices are capable to measure size-resolved viral airborne environmental contamination successfully. In the current project you will investigate ways to improve airborne viral exposure assessment and measurement strategies to enhance future risk assessment. In longitudinal sampling campaigns in settings with known high viral pressure, e.g nursing home, day-care or animal facilities, various proven sampling devices and measurement strategies will be tested. In addition, optimizing current bio-aerosol air sampling devices based on physics characterization and enhancement of viral detection techniques will be studied experimentally for various virus families in conjunction with project 1. This project will be executed at the Institute for Risk Assessment Sciences (IRAS), Utrecht University under supervision of Dr. Inge Wouters.

• We are looking for PhD students that are enthusiastic and highly motivated with a MSc degree or equivalent from an accredited academic program in Biology, Biomedical or Molecular Sciences, Epidemiology or (Veterinary) Medicine.
• Demonstrable affinity with various molecular and/or and virological techniques will be beneficial. Background knowledge on exposure assessment is a pre.
• You have an excellent command of the English language, both oral and written. For Project 2 and 3 knowledge of the Dutch language is also required.
• Candidates are expected to obtain their PhD in 4 years.

You will receive a temporary PhD position for 4 years. The gross monthly salary is € 2.631,- in the 1st year and increases to € 3.336,- in the 4th year. The terms of employment are according to the Collective Bargaining Agreement for Dutch University Medical Centers (CAO UMC).

Erasmus MC

Erasmus MC, TU Delft and Erasmus University Rotterdam have joined forces in the Pandemic and Disaster Preparedness Center (PDPC). PDPC aims to prepare society for future pandemics and disasters. We will reduce vulnerabilities and risks and build resilience through effective disaster prevention, preparedness and recovery measures. Convergence of the technical, medical and social sciences is essential for developing the next generation of approaches to disasters and pandemics. In the foreseeable future, our society can expect many more and unforeseen virus outbreaks and extreme events because of climate change. But how do we protect society from the next pandemic or disaster? Which of the lessons learnt could develop prevention and intervention measures, and how could research contribute to preparedness?

One of the frontrunner projects in the PDPC is about predicting, measuring and quantifying airborne virus transmission, because the ability to spread via the air is a key determinant of pandemic potential of zoonotic respiratory viruses. Quantification of infectious viruses in air and assessing their transmission potential via small or large respiratory droplets is crucial for risk assessments of zoonotic and pandemic outbreaks but is notoriously difficult to perform. The aim of this frontrunner project is to develop methods to predict and quantify the airborne transmission potential of viruses, based on model studies, experiments and outbreak research, that may lead to novel and improved mitigation strategies. This interdisciplinary project brings together scientists from the fields of medicine, virology, epidemiology, public health, exposure science, engineering, physics and electronics in 4 interconnected work packages and PhD candidates are recruited here for 3 of these work packages.

The Department of Viroscience at Erasmus MC houses more than 150 employees of different disciplines and runs an extensive experimental research program on the epidemiology, pathogenesis, prevention and treatment of infections by human and animal viruses. All necessary equipment to carry out the research proposed in the projects is available within the setting of the department. The Department of Viroscience harbors well-equipped clinical and experimental virology labs, in which all the virology, molecular biology, pathology and immunology techniques necessary for these projects are operational. The PDPC program at the Viroscience department is connected to many long-term and short-term projects nationally and internationally.

The Institute for Risk Assessment Sciences (IRAS) is is an interfaculty research institute (collaboration of the faculties of Veterinary Medicine, Medicine and Science) at Utrecht University. IRAS mission is to provide education and research on the human and environmental health risks of exposure to potentially harmful agents in the environment where research takes place within the domains of Toxicology, Environmental Epidemiology and Veterinary Public Health. The institute is composed of experts in exposure science, toxicology, molecular biology, epidemiology, and veterinary and human medicine. Together we are generating critical insights in how the environment is affecting the health of humans and animals. The PDPC program is connected to other long-term and short-term One Health projects within IRAS.