Lab interests

Pathogen evolution and long-term persistence including that of SARS-CoV-2

Effects of HIV co-infection on SARS-CoV-2 and other pathogens

Escape of SARS-CoV-2 variants from the antibody neutralization immune response elicited by vaccines and other variants

Lab PI and members

Alex Sigal is faculty at the Africa Health Research Institute and Associate Professor at the University of KwaZulu-Natal. Alex has a PhD in Systems Biology from the Weizmann Institute and was a postdoctoral fellow with David Baltimore at the California Institute of Technology. Sandile Cele, Farina Karim, and Khadija Khan, all from KwaZulu-Natal, South Africa, are PhD students in the lab and lead many of the projects. Lab staff are Dr. Laurelle Jackson (Research Associate), Yashica Ganga (Lab supervisor), Zesuliwe Jule (Technologist), Kajal Reedoy (Technologist), and Mallory Bernstein (Data Specialist).


Omicron infection enhances neutralizing immunity against the Delta variant. Manuscript.

Publications 2021-2022

SARS-CoV-2 prolonged infection during advanced HIV disease evolves extensive immune escape. Cell Host & Microbe.

Omicron extensively but incompletely escapes Pfizer BNT162b2 neutralization. Nature.

Escape of SARS-CoV-2 501Y.V2 from neutralization by convalescent plasma. Nature.

Immunogenicity of SARS-CoV-2 infection and Ad26.CoV2.S vaccination in people living with HIV. Clin Infect Dis.

HIV status alters disease severity and immune cell responses in beta variant SARS-CoV-2 infection wave. eLife.

T cell derived HIV-1 is present in the CSF in the face of suppressive antiretroviral therapy. PLos Pathogens.

Aggregated Mycobacterium tuberculosis Enhances the Inflammatory Response. Frontiers.

Similar antibody responses against SARS-CoV-2 in HIV uninfected and infected individuals on antiretroviral therapy during the first South African infection wave. Clin Infect Dis.

Sixteen novel lineages of SARS-CoV-2 in South Africa. Nat Med.

Detection of a SARS-CoV-2 variant of concern in South Africa. Nature.

Efficacy of the ChAdOx1 nCoV-19 Covid-19 Vaccine against the B.1.351 Variant. N Engl J Med.

Multiple SARS-CoV-2 variants escape neutralization by vaccine-induced humoral immunity. Cell.

Two doses of SARS-CoV-2 vaccination induce robust immune responses to emerging SARS-CoV-2 variants of concern. Nature Communications.

Aggregation state of Mycobacterium tuberculosis impacts host immunity and augments pulmonary disease pathology. Communications Biology.

Reduced antibody cross-reactivity following infection with B.1.1.7 than with parental SARS-CoV-2 strain. eLife.