UNLV Researcher on the Curious Case of COVID-19 Reinfection – UNLV NewsCenter

Once youve had COVID-19, youre safe from getting it again, right?A northern Nevada man learned the hard way earlier this year that getting re-infected with COVID-19 soon after surviving it just might be possible. After testing positive in April, the man subsequently tested negative multiple times until becoming ill just 48 days later and testing positive again in June.To figure out what was going on, scientists from the Nevada State Public Health Laboratory at the University of Nevada, Reno, along withUNLV researcher Richard Tillett with the Nevada Institute of Personalized Medicine, looked deeper into the genetic blueprint of the mans virus samples and found differences between the two cases.In other words, he was infected twice.Thankfully, reinfection looks to be pretty uncommon, says Tillett. And I hope that it remains that way.Still, the work conducted by Tillett and colleagues uncovered the first confirmed case of a person reinfected with the virus in North America. Their research was published in the prestigious medical journal The Lancet InfectiousDiseases in October.

The scientific community in Nevada and beyond has rallied together like never before to uncover the many mysteries of COVID-19.Tillett, a biostatistician, joined UNLV in August after working with the Nevada Center for Bioinformatics in Reno. He studies the genome or building blocks of disease, and his work with the Nevada Institute of Personalized Medicine is now squarely focused on finding ways to conquer COVID-19.We spoke with Tillett to learn more about the likelihood of COVID-19 reinfection, the teams landmark study, whats next, and his advice for what we can all do to keep ourselves and our loved ones safe.

My role in this study was to analyze the virus genomes collected from this patient from his earlier and later positive tests, compare the genomes to one another and to genomes in circulation, and finally, either find evidence that the two viruses differed or rule it out.

We identified the man, a Washoe County resident, as a part of our effort to survey SARS-CoV-2 genomes across Nevada. With both public health labs in the state providing samples, corresponding author Dr. Mark Pandori, director of the Nevada State Public Health Lab with the University of Nevada, Reno, was able to identify the man.

We started with a basic set of facts in the testing history. We knew that the patient had tested positive via the PCR test, which is used to diagnose active infection. He had symptoms, then improved. He subsequently had two negative tests, indicating his infection was over. Then six or seven weeks after his first positive test, he felt sick again, got tested again, and was again positive.Now, PCR test results like these are only suggestive of re-infection. In order to confirm reinfection, we needed to sequence the viral genomes from both positive tests. When we obtained those genome sequences, we found six differences between the virus in the samples, by which we were able to rule out alternative scenarios such as it being one long infection.

Honestly, I felt fright. We had to be sure we were right if we were going to claim proof that the possibility of reinfection was more than possible, but had actually happened for this person.

Currently, reinfection looks to be pretty uncommon. And I hope that it remains that way. Though we don't yet know how long an average person may have lasting immunity to SARS-CoV-2, less than a year into this pandemic, it currently looks like reinfection is not the norm.

My advice is to stay vigilant. Wear masks. Social distance. Avoid gatherings. Wash your hands. And if you feel like you maybe haven't been doing a great job at enacting these suggestions, this is too important to beat yourself up over. Remember that its not too late to start or restart lowering your exposure risk.

The research community here in Nevada, the U.S., and globe are doing great work together in response to the pandemic and have embraced collaboration and knowledge-sharing to help tackle this threat. Our hope is that continued study will help us understand this virus, track it, monitor unfolding outbreaks, and keep guard in the future, even after vaccines become widely available.

At the Nevada Institute of Personalized Medicine, my colleagues including Professor Edwin Oh and I are continuing to track and study COVID-19 genomes from Nevada patient samples.Weve begun a major effort to detect SARS-CoV-2 in wastewater, and once detected, identify the mixture of mutations found in the viruses in that wastewater. This work will give us a tremendous amount of new information on the burden and spread of this virus in the community complementary to and beyond patient samples.