3 Questions with João Pessoa

BioPhotonics spoke with João Pessoa, a postdoctoral researcher at the Institute of Molecular Medicine at the University of Lisbon in Portugal. We inquired about how the COVID-19 outbreak has affected the research community in Portugal, and the role of optical technologies in the study and treatment of the virus.

How has COVID-19 affected the research community in Portugal?

During the first wave of the outbreak in Portugal, research institutes were closed for their primary research activities between March and May. After that period, we have been doing our onsite research projects in alternating schedules (to lower the number of people in the labs simultaneously), and working from home whenever possible.

Researchers have been communicating with society at large about the disease, how to prevent it, vaccines under development, and therapeutic perspectives. They also designed and conducted new research projects on SARS-CoV-2 and COVID-19.

My institute has joined some initiatives, including a collaborative project to determine the percentage of residents in Portugal who have developed anti-SARS-CoV-2 antibodies. A total of 12,000 volunteers from all regions of the country and from different age groups have collaborated and contributed data on the prevalence of the infection in Portugal. Another major initiative was a COVID-19 diagnosis task force. Rapid diagnosis is essential to prevent this highly contagious disease. Labs and resources were repurposed for performing diagnostic tests and have increased the national diagnostic capacity. This initiative contributed to lowering the spread of the disease during its first outbreak.

What has the role of optical technologies been in COVID-19 investigation?

Optical technologies are essential in COVID-19 diagnosis. The standard methodology used — reverse transcription quantitative polymerase chain reaction (RT-qPCR) — provides a fluorescent readout, which depends on the presence of viral genetic material in the patient’s sample.

Alternative approaches, to make diagnosis quicker, cheaper, and less resource-consuming, have been developed. Instead of taking patients’ samples to an equipped lab, these newer methodologies are portable and can provide the final result on-site. They usually deliver the result as a fluorescent readout in a reaction container or as a colored mark on a test stripe. They are less dependent on optical equipment, and in at least one of these approaches, the output can be detected using a mobile phone-based fluorescence microscope.

In the serological tests for SARS-CoV-2 antibody detection, the readout is frequently fluorescence or chemiluminescence, both generated upon antibody detection in the patient’s sample.

Although viruses are too small to be visualized through light microscopy, optical technologies can also be useful in their research. Using a light microscope, SARS-CoV-2 proteins and genetic material were already visualized inside infected cells, through colorimetric labeling of these components.

What findings might these technologies uncover?

From the information already described, we may expect optical technologies to remain involved in development of alternative COVID-19 diagnostic methods and in SARS-CoV-2 research. They should uncover the specificity and sensitivity of newer diagnostic methods. Moreover, optical microscopy may uncover cellular details of SARS-CoV-2 infection. Those may include subcellular localization of the viral particles and, through combination with other labeling methods, potential interactions within the cell.