Alejandro B. Balazs, PhD

Lab Info:

Principal Investigator: Alejandro B. Balazs, PhD

Lab Staff: 4 graduate students, 5 technicians

Office/Location: 400TS 992

Phone: (857) 268-7197


Category: Core Members, Ragon Members

Dr. Alejandro B. Balazs is a Group Leader at the Ragon Institute of MGH, MIT and Harvard, where he serves as the Scientific Director of the Human Immune System Mouse Program. He is also an Assistant Professor of Medicine at Harvard Medical School and an Assistant in Immunology at MGH.


Dr. Balazs uses engineered immunity as a tool to dissect host-pathogen interactions and address the most pressing questions in the field of vaccine development. As a postdoctoral fellow in the lab of David Baltimore, Dr. Balazs developed a novel AAV platform for the systemic delivery of broadly neutralizing antibodies in vivo. This technology, known as Vectored ImmunoProphylaxis (VIP), has shown the ability to engineer durable immunity to numerous pathogens in mice, including HIV, influenza, herpes simplex virus, hepatitis C, and malaria. Dr. Balazs currently uses VIP to study HIV evolution in response to a variety of engineered antibody responses, with the goal of designing maximally effective antibody combinations for prophylactic or therapeutic use. His work with this groundbreaking technology has led to a clinical trial testing VIP as a potential HIV vaccine modality. Dr. Balazs also brings an engineering perspective to improving humanized mouse models, with the aim of providing better tools for investigators at the Ragon Institute and beyond.


He is the recipient of numerous honors, including a research fellowship from the Foundation for AIDS Research (amfAR), the MGH Transformative Scholars Award, and the New Innovator Award from the National Institute on Drug Abuse.


Dr. Balazs completed postdoctoral training in virology and immunology at the California Institute of Technology. He received a PhD in genetics from Harvard University and a BS in microbiology and molecular genetics from the University of California, Los Angeles.


Laboratory Website:


Current areas of investigation

  • Understanding the mechanisms of sterilizing immunity by antibodies in vivo.
  • Exploring the means by which pathogens escape antibody responses
  • Determining the role of innate immunity mediated by antibodies in protection against viral infection.

Selected publications

de Jong YP, Dorner M, Mommersteeg MC, Xiao JW, Balazs AB, Robbins JB, Winer BY, Gerges S, Vega K, Labitt RN, Donovan BM, Giang E, Krishnan A, Chiriboga L, Charlton MR, Burton DR, Baltimore D, Law M, Rice CM, Ploss A.  Broadly neutralizing antibodies abrogate established hepatitis C virus infection. Sci Transl Med 2014 Sept 17; 6(254):254ra129. doi: 10.1126/scitranslmed.3009512 PMID: 25232181


Deal C, Balazs AB, Espinosa D, Zavala F, Baltimore D, Ketner G. Vectored antibody gene delivery protects against Plasmodium falciparum sporozoite challenge in mice. Proc Natl Acad Sci 2014 Aug 26; 111(34):12528-32. doi: 10.1073/pnas.1407362111 Epub: 2014 Aug 11. PMID: 25114213


Balazs AB, Ouyang Y, Hong CM, Chen J, Nguyen SM, Rao DS, An DS, Baltimore D.  Vectored ImmunoProphylaxis Protects Humanized Mice from Mucosal HIV Transmission. Nature Medicine, 2014 Mar;20(3):296-300, Online Publication, Feb 9, 2014. doi: 10.1038/nm.3471 PMID: 22139420


Balazs AB, Bloom JD, Hong CM, Rao DS, Baltimore D. Broad protection against influenza infection by vectored immunoprophylaxis in mice. Nat. Biotech. 2013 Jul;31(7):647-52. Online Publication Jun 2, 2013. doi: 10.1038/nbt.2618 PMID: 23728362


Balazs AB, West AP Jr. Antibody gene transfer for HIV immunoprophylaxis. Nat. Immunol. 2013 Jan; 14(1):1-5. doi: 10.1038/ni.2480 PMID: 23238748


Balazs AB, Chen J, Hong CM, Rao DS, Yang L, Baltimore D.  Antibody-based protection against HIV infection by vectored immunoprophylaxis. Nature, 481(7379):81-84 Online publication Nov 30, 2011. doi: 10.1038/nature10660 PMCID: PMC3253190


Sigal A, Kim JT, Balazs AB, Dekel E, Mayo A, Milo R, Baltimore D. Cell-to-cell spread of HIV permits ongoing replication despite antiretroviral therapy. Nature, 2011 Aug  17;477(7362):95-8. doi: 10.1038/nature10347 PMID: 21849975


Luo XM, Lei MY, Feidi RA, West AP Jr, Balazs AB, Bjorkman PJ, Yang L, Baltimore D. Dimeric 2G12 as a potent protection against HIV-1. PLoS Pathog. 2010 Dec 16;6(12):e1001225. doi: 10.1371/journal.ppat.1001225 PMCID: PMC3002980

Laboratory Members