Quantifying Antibody Persistence After a Single Dose of COVID-19 Vaccine Ad26.COV2.S in Humans Using a Mechanistic...

Area of Science:

• Immunology
• Vaccinology
• Mathematical Modeling

Background:

• Understanding COVID-19 vaccine-induced humoral immunity persistence is crucial for determining protection duration and optimal booster timing.
• The Janssen Ad26.COV2.S vaccine is a single-dose option for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) prevention.

Purpose of the Study:

• To characterize the time course of humoral immune responses after a single Ad26.COV2.S vaccination.
• To quantify antibody response persistence using mechanistic modeling and predict long-term trends.

Main Methods:

• Developed a mechanistic model to analyze SARS-CoV-2 neutralizing antibodies (wtVNA) and spike protein-binding antibodies (S-ELISA) titers.
• Analyzed 442 wtVNA and 1,185 S-ELISA titers from 82 and 220 participants, respectively, up to 8 months post-vaccination.
• Simulated antibody persistence up to 24 months post-immunization.

Main Results:

• The mechanistic model accurately described the temporal dynamics and variability of wtVNA and S-ELISA titers up to 8 months.
• Simulations indicated durable but waning antibody responses lasting up to 24 months after a single Ad26.COV2.S dose.
• Older adults showed decreased memory B cell production, while women had increased antibody production from long-lived plasma cells compared to men.

Conclusions:

• Single-dose Ad26.COV2.S vaccination elicits long-lasting antibody responses, though waning is predicted up to 24 months.
• Age and sex influence antibody persistence, with faster waning observed in older adults and men.
• Mechanistic modeling provides valuable insights into vaccine-induced immune response dynamics and longevity.