Serological assessment of the durability of vaccine-mediated protection against SARS-CoV-2 infection
Year: 2023
Type: conference-abstract
Abstract: Virus-specific neutralizing antibodies are generally accepted as a correlate of protection against infection, though many questions remain about which components of the immune response protect against SARS-CoV-2 infection. We longitudinally measured Spike receptor binding domain (RBD)-specific serum IgG and nucleocapsid protein (NP)-specific serum IgG in a human cohort immunized with the Pfizer BNT162b2 vaccine. Serum samples were collected and stored at −80 °C. Antibody titers were quantitated using an endpoint dilution ELISA and reported as inverse titers. A four-fold or greater increase in NP-specific antibody titers was used as serological marker of clinical infection at some point prior to the sample collection. Using the RBD-specific IgG titer measured in participants’ serum collected prior to seroconversion for NP, we were able to calculate a protective threshold titer for RBD-specific IgG. We calculated the rate of decay of antibodies in participants who did not exhibit a four-fold increase in NP-specific IgG, i.e. had no serological evidence of infection, and found that, on average, the RBD-specific IgG response waned below the protective threshold by four months following vaccination. These data highlight the need for a more durable immune response to vaccination which may require different adjuvants, dosages, or vaccination schedules. This work was supported by The Robert M. Hearin Foundation, The Bower Foundation, and James L. Barksdale.
Source: The Journal of Immunology
Institution: University of Mississippi Medical Center
Language: English
Subfield: Infectious Diseases
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W4385686134