Research Highlights

Platform Optimization and Therapeutic mRNA

CRISPR/Cas9  is the powerful genome editing tool that can be used to treat diseases on the genetic level. Hereditary disorders (e.g. hemophilia, sickle cell disease, muscular dystrophy and many others) can be resolved by correcting the faulty gene or by inserting the correct one. We are using our lab’s expertise to develop mRNA-LNP-based platform to be able to knock in genes of interest in vivo, without the removal and selection of target cells. Current knock in technologies, such as CAR T cell treatments require ex vivo processing of cells, and usually employ lentiviral knock-in strategies, which integrate randomly into the genome, and thus can cause unwanted complications (e.g. oncogenesis). CRISPR/Cas9 is highly site-specific, so a ”safe harbor” can be selected as the region of integration. The mRNA-LNP platform has the advantage of expressing the effector enzyme, Cas9, only for a short time compared with DNA-based approaches, in which case continued expression of Cas9 can lead to rare off-target events.

Project Leader: Istvan Tombacz

Lab members participating in the project: Mohamad-Gabriel Alameh, Benjamin Davis

mRNA vaccine or therapeutic are typically synthesized in in vitro transcription (IVT) crucially including both DNA-dependent RNA polymerases (e.g., T7, T3, and SP6) and plasmid containing the gene of interest as template. The former represents a very common process commercially available, while the latter varies greatly depending on the client, involving protein sequence resource, application in clinic or research, and delivery to target tissues. Through this platform, we optimize genetic codes, regulatory elements, and leader peptides. The optimized mRNA structure is de novo synthesized and cloned in DNA vector using BioXp 3200. The DNA vector acts as a template in IVT to synthesize mRNA.  

Project Leader: Jibin Zhou


Lipid nanoparticles (LNP) are carriers of nucleic acids with proven clinical relevance. Their use in the latest SARS-CoV-2 mRNA vaccines proved to be a success. Therefore, understanding how LNP interact with the immune system and their contribution to vaccine responses is fundamental for the development of future generations of lipid-based carriers.

Team Leaders: Mohamad-Gabriel Alameh

Lab members participating in the project: Istvan Tombacz

We have used lipid nanoparticles (LNPs) for the delivery of nucleoside-modified mRNA in small and large animal models. The unmodified classical LNP formulations have usually been found to target the liver after systemic delivery. In the past few years, Hamideh has developed a targeted LNP-mRNA platform, with good targeting capacity against various tissues and cell types.  Her current projects are mainly focused on applying and optimizing the targeted platform to address a variety of disorders such as acute pathological conditions, infectious diseases, cancer, and fibrosis.

Project Leader: Hamideh Parhiz

Lab members participating in the project: Tyler Papp, Istvan Tombacz, Xiomara Mercado-Lopez


HIV Eradication and Cure

People living with HIV must remain on life-long therapy due to the maintenance of long-lived viral reservoirs. HIV Cure efforts seek to eradicate or control these reservoirs and prevent viral rebound upon treatment interruption. The Weissman Lab is applying the mRNA-LNP platform to eradicate and control HIV through both systemic and targeted delivery of therapeutic RNAs. Current efforts include broadly neutralizing antibody (bnAb) and cellular immunotherapy, gene therapy, therapeutic vaccination, and genomic engineering for DNA proviral inactivation or excision.

Project LeaderTed Kreider

Lab members participating in the project:  Hamideh Parhiz, Amie AlbertusIstvan TombaczTyler Papp, Brieyanna McWilliams



In autoimmune disease, the immune system aberrantly destroys healthy tissue, leading to a variety of debilitating and life-threatening pathologies. The Weissman Lab is developing tolerizing vaccines to prevent reverse autoimmune tissue destruction in diseases such as type 1 diabetes, multiple sclerosis, and Celiac disease.

Team Lead: Jilian Melamed

Lab members participating in the project: Michael Kegel, Jenna Muscat-Rivera

Clostridioides difficile (C. difficile) is a bacterium that causes recurrent infection in humans, leads to hospitalization, and death in severe cases. The US Center for Disease Control (CDC) classifies C. difficile as an urgent threat. The development of a prophylactic vaccine would save thousands of lives per year in the US alone and would reduce economic burden on society.

Project Leader: Mohamad-Gabriel Alameh

SARS-CoV-2, the etiological agent of COVID-19, is a pandemic causing virus with a relatively high rate of mutations. The anti-SARS-CoV-2 mRNA-based vaccine was granted emergency use in several countries and showed efficacies above 90% in Phase II clinical trials and during roll out. The development of improved immunogens (including pan corona immunogens) has the ultimate goal of reducing dose and cost, thus increasing the number of potential vaccinees globally and protecting them against circulating and emerging coronaviruses (with or without pandemic potential).

Project Leader: Mohamad-Gabriel Alameh

Lab members participating in the project: : Istvan Tombacz, Benjamin Davis

The COVID-19 pandemic is a serious threat to human health, quality of life and the economy. The resolution of this situation is only possible with the deployment of highly effective vaccines. Currently approved vaccines, such as the Pfizer/BioNTech, Moderna, Astra-Zeneca and Sputnik V will possibly be able to prevent further serious consequences of the outbreak. However, there are valid concerns of new SARS-CoV-2 strains appearing worldwide, both because of higher morbidity/mortality and higher resistance to vaccine-induced protection. Thus, a vaccine that is able to effectively combat a broader spectrum of virus variants is desirable. We are looking into multiple diverse strategies to develop such a vaccine. One approach is to use antigens more conserved than the Spike protein (which is used in all current vaccine formats). Such a vaccine would not only be able to protect against currently evolving SARS-CoV-2 strains, but also possible future outbreaks of related coronaviruses.

Project Leader: Istvan Tombacz

Lab members participating in the project: Mohamad-Gabriel Alameh, Benjamin Davis

Hepatitis C

Hepatitis C Virus (HCV), is a major public health threat in the United States as well as around the globe, with over 2.4 million people infected nationwide and over 70 million infected globally. In the US each year, an additional 50,000 people become infected and over 15,000 die from HCV. The infection rate has increased by 200% over the last 10 years, fueled largely by the ongoing opioid crisis. Despite the availability of a highly effective cure, many limitations of this treatment prevent us from treating our way out of this epidemic. Mathematical modeling has shown that a vaccine with even a modest efficacy would be a tremendous tool in the effort to wipe out HCV. This project aims to develop an mRNA vaccine that elicits antibodies capable of neutralizing many different subtypes of HCV to protect vaccinees from infection.

Project Leader: Erin K. Reagan

Lab members participating in the project: : Xiomara Mercado-LopezElena N. Vasserman-AtochinaHouping Ni

Millions of people are infected with herpes simplex virus (HSV) worldwide. Infection in older children and adults is common and burdensome, but generally not life-threatening. In contrast, HSV infection in neonates can cause death or developmental disability. Neonates are most often infected during labor and delivery. The highest risk occurs when women acquire primary genital HSV infection late in pregnancy, but maternal infections are usually asymptomatic or unrecognized.  Lower risk occurs when mothers develop some immunity to HSV prior to delivery, suggesting that vaccinating women could protect neonates. We are therefore pursuing maternal vaccination as the best strategy to prevent neonatal herpes.

In collaboration with the Friedman lab, we are developing a vaccine for HSV using the mRNA-LNP platform.  Our vaccine candidate protects against genital HSV infection in animal models. In this ongoing project, the HSV mRNA vaccine candidate is being evaluated in a mouse model of neonatal HSV infection, and the adaptive immune response elicited by maternal vaccination compared to that generated following maternal genital infection. These studies are crucial to the development of a universal HSV vaccine that prevents infection across the lifespan.

Project Leader: Angela Desmond

Lab members participating in the project Mohamad-Gabriel Alameh

Harvey Friedman Lab: Sita Awasthi, Lauren Hook, Kevin Egan, Alexis Naughton, John Lubinski, Phil LaTourette (former)

Despite decades of research, a preventative HIV vaccine remains elusive. The Weissman Lab is applying the mRNA-LNP platform to develop the next generation of HIV immunogens and preventative interventions. Novel immunogens with enhanced expression and favorable antigenicity are being designed that engage broadly neutralizing antibody precursors and shepherd their development into maturity. Further, mature broadly neutralizing antibodies are being expressed from mRNA-LNPs to passively prevent HIV acquisition.

Project Lead: Ted Kreider

Lab members participating in the project: Amie Albertus, Brieyanna McWilliams

Influenza outbreaks occur annually, resulting in more than 3 million severe illness cases and up to 650,000 deaths. The constant antigenic changes of Influenza virus envelope proteins make them resistant to our herd immunity. As a result, the annual Influenza licensed vaccines provide some level of protection only against the circulating influenza virus strains. Thus, using mRNA-LNP platform, we are developing an improved seasonal Influenza virus mRNA vaccine by optimizing immunization regimens and valency to elicit broad and durable protection against seasonal influenza.  

Project Leader: Xiomara Mercado-Lopez

Lab members participating in the project: Qin Li

Influenza virus outbreaks occur annually resulting in approximately 3 to 5 million cases of severe illness and up to 650,000 deaths. Large influenza pandemics resulted in millions of deaths. Influenza viruses undergo constant changes in the antigenic characteristics of their envelope glycoproteins, which allows them to evade human herd immunity. Thus, influenza vaccines must be rapidly produced each year to match circulating viruses, a process constrained by dated technology and vulnerable to unexpected strains emerging from human and animal reservoirs. The effectiveness of the current seasonal influenza vaccines is about 10-60% because of the frequent antigenic variation.

A universal influenza mRNA vaccine can be designed to provide long-lasting protection with high effectiveness from constantly mutating influenza strains, including strains that can cause pandemics. A universal vaccine will reduce the number of vaccinations and the resulting cost in a person’s lifetime. More importantly, more people may be inclined to get the vaccine. Therefore, the universal vaccine will increase the acceptance of immunization and enhance the herd immunity of the population against influenza viruses.  
The novel mRNA vaccine technology greatly shortens vaccine development time. The strong immune response along with substantial breadth and potency elicited by the mRNA vaccine in vivo makes it a strong contender against influenza viruses. With the discoveries of the novel immunogens, the characterization and modification of their constructs, and the efficient mRNA delivery system, we expect a universal mRNA vaccine for influenza viruses to enter clinical trials within the next two years. 

Project Leader: Qin Li

Lab members participating in the project: : Ruiqi Shi, Xiomara Mercado-Lopez, Houping Ni

Lyme disease has emerged as the most common vector-borne infectious disease in the United States.  Although the CDC reports 30,000 cases annually, the actual estimate is likely closer to 300,000.  It is transmitted through the bite of an Ixodes tick carrying the bacterial pathogen Borrelia burgdorferi.  Current standard of care is an antibiotic regimen, but as infection with B. burgdorferi is difficult to detect and often misdiagnosed, delay in treatment can lead to severe pathology.  As of now, there is no FDA-approved preventative treatment for Lyme disease.

This project aims to develop a prophylactic vaccine utilizing the mRNA-LNP platform.  As there are 16 diverse strains of B. burgdorferi that cause Lyme disease, protection across strains is crucial.  The mRNA-LNP platform has never been used against a bacterial target.  Thus, our novel approach to Lyme disease mRNA vaccine development could prove to be an effective method for reducing the pervasiveness of this illness.

Project Leader: Matthew Pine


Noroviruses (NoV) belong to the family Caliciviridae. They are a group of non-enveloped, single-stranded RNA viruses that are the most common cause of acute gastroenteritis (AGE) worldwide, annually causing an estimated 685 million cases. The risk of severe NoV AGE is increased in children <5 years old and in adults >65 years old.  About 200 million cases are seen among children under 5 years old, leading to an estimated 50,000 child deaths every year, mostly in developing countries.  Among the 2.7–4 billion diarrheal cases that are globally diagnosed every year, about 18% are associated with NoV infection, without significant differences between developed (20%) and developing countries with low diarrhea-related mortality (19%).  In 2016 the World Health Organization stated that the development of a NoV vaccine should be considered an absolute priority.  However, the development of an effective NoV vaccine has been extremely difficult for many years due to the lack of adequate cell lines for viral culture and successful animal models for drug evaluation.

In this project, we are developing an mRNA norovirus vaccine, using a novel mRNA platform technology developed in our laboratory. Application of mRNA vaccines technology opens revolutionary approaches towards infectious diseases, particularly as rapid response platforms to help deal with outbreaks, because of their high potency, safe administration, rapid development, and low-cost of manufacture.

Project Leader: Elena N. Atochina-Vasserman

Lab members participating in the project: Nathan Ona, Jaclynn Meshanni, Ishana Baboo