The Rossi Lab

Our Research Goals

The main objective of the Rossi lab is to elucidate how viruses cause outbreaks, and creating and testing countermeasures to combat the diseases they cause. With a primary focus on arboviruses (such as Zika, chikungunya, Mayaro, West Nile, Venezuelan equine encephalitis virus, and Powassan virus), we research the mechanisms and transmission of infection. We collaborate with several labs to elucidate the evolutionary influences of infection, model the potential for viruses to ‘spill back’ into nature and characterize novel and understudied arboviruses.

Our ultimate quest? To use our knowledge to improve the response to infectious disease outbreaks and mitigate the impact of arboviruses through vaccine and therapeutic development.

If you want to hear more, Dr. Rossi was recently on an episode of Infectious Science Podcast.

Viruses and Outbreaks

An outbreak is an increase in disease within a defined space and time which is above the normal levels. Some recent outbreaks of note included Ebola (West Africa: 2014-2016), Zika (Americas: 2015-2016) and COVID19 (worldwide: 2020-2023). We’ve reviewed recent outbreaks and some factors that contribute to them here. Not all viruses continuously circulate directly between people, so understanding the transmission cycles that maintain the virus during epidemics is critical. For example, Zika virus also infects non-human primates, which live in forests worldwide like the Amazon. Understanding the effects of viral ‘spill back’ into nature from human epidemics is essential, as this may serve as a source for future outbreaks. We’ve collaborated with the Vasilakis and Hanley labs to help answer this question.

Testicular Infection

One interesting lesson from the Zika outbreak was the realization Zika virus (ZIKV) could be transmitted between people without the intermediate mosquito vector. Sexual transmission for arboviral infections is relatively uncommon, or at least not commonly recognized, and is an active area of research. We’re evaluating the capacity for ZIKV to infect the testes, including the main cell types, and tease apart of the contribution of the immune response to pathogenesis. Our preliminary results are summarized here.

Translating lessons from one type of viral infection or disease to another can be helpful. Early during the COVID19 pandemic, we saw similarities between the original SARS reports of testicular swelling and our ZIKV research, leading us to hypothesize SARS-CoV-2 might similarly infect the testes of some men. This led us to develop a hamster model for SARS-CoV-2 testicular infection, which is currently being expanded upon.

Countermeasure Research: Antivirals, Vaccines and Animal Models

Until AI and mathematical models can recapitulate every aspect (including the diversity in biology and immunological memory) of infection within a host, animal models are essential for not only understanding infection kinetics (and vector transmission) and pathogenesis, but antiviral and vaccine screening.

A major focus for the lab includes antiviral testing for Venezuelan equine encephalitis virus (VEEV). In partnership with Drs. Colleen Jonsson and Jennifer Golden as part of a U19 CETR grant, we help to evaluate lead antiviral candidates in vivo. We have also worked closely with other groups and pharmaceutical companies to screen lead vaccine candidates.

We’ve also collaborated with the Coffey lab to develop a rhesus macaque model for MAYV disease and mosquito infection dynamics. The goal is not only to describe and quantify the infection and disease in this model for the purposes of antiviral and vaccine development against Mayaro disease, but also to understand the contributions and interplay between the mammalian host, viremia and feeding mosquito species.