GVN Center and Member Spotlight

March 5, 2021 – GVN SPOTLIGHT ON:

Mohammad Sajadi

Associate Professor of Medicine, Division of Clinical Care and Research,
Institute of Human Virology, University of Maryland, School of Medicine, USA

What are you and your institution currently working on regarding COVID-19?

Early in the in pandemic, our lab developed the tools we needed to study the humoral responses to SARS-CoV-2. These include a variety of ELISAs, a pseudovirus assay, and isolation of monoclonals. We have been studying the humoral responses to SARS-CoV-2 in outpatients and inpatients. More recently, we have studied the humoral responses in those vaccinated against COVID-19.

Please describe in detail your work with vaccine response to the COVID-19 vaccine.

Our lab joined up with the epidemiology group (headed by Dr. Anthony Harris) to carry out a CDC-funded study that focuses on secondary responses of healthcare workers (HCWs) to the SARS-CoV-2 envelope protein. Earlier in the summer of 2020, Dr. Harris led an effort to conduct a serosurvey of several thousand HCWs at our hospital. We studied immune response to the Pfizer-BioNtech and Moderna vaccines in a subset of these individuals who were either SARS-CoV-2 seronegative or seropositive (those with symptomatic and relatively asymptomatic diseases). After one dose of vaccination, the seropositive group had clear secondary response by peaking binding titers by day 7, and by inducing neutralization titers 500 times higher than seronegative group by day 14 (Saadat et al. JAMA 2021). This and other similar studies have led to the consideration of giving one dose of vaccine to the previously infected individuals. Accordingly, the government of France is the first country to change its guidelines.

Professional Summary

I am a physician scientist with training in Internal Medicine and Infectious Diseases. My main area of research prior to the Covid-19 pandemic including studying humoral immune responses to infection, especially HIV-1. We have an active program in understanding the humoral responses to HIV-1 envelope, especially antibodies that can neutralize multiple different strains of HIV, i.e., broadly neutralizing antibodies (bNAbs).

During the past decade we have been characterizing the antibodies in the serum of rare HIV-infected persons who have bNAbs. As part of this work, we have developed new methods to characterize and isolate monoclonal antibodies from patients that are targeted (any circulating antibody), accurate, and efficient. In doing so, we have isolated a new family of broadly neutralizing antibodies that represent the broadest and most potent mAbs against HIV-1 described to date. We are currently involved in engineering and preclinical development of these monoclonal antibodies with the hope that they can be used to treat and/or prevent HIV-1 infection.

Overview of The Institute of Human Virology, Division of Clinical Care and Research

HIV and AIDS are top priorities at the IHV as our scientists seek to better understand how to treat and prevent viral diseases. The newest discoveries in the fight against chronic viral diseases associated with AIDS, HIV and cancers are available at the IHV’s Clinical Center. Patients may participate in research projects involving these new therapies. Patients and their physicians work in partnership to determine if and when to participate in a research project. We also provide our patients with information about research projects at other research centers.

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