Speaker
Description
Despite the availability of vaccines, infectious diseases such as COVID-19, tetanus, diphtheria, and pertussis remain persistent public health threats, particularly among vulnerable populations including pregnant and lactating women. As most research on protection against infectious diseases to date has focused on antibody-mediated responses, understanding how antibodies behave over time remains an important aspect for elucidating disease dynamics.
Although both COVID-19 and Tdap (tetanus, diphtheria, acellular pertussis) vaccines are approved and recommended for pregnant and lactating women in Belgium, limited data exist on antibody kinetics and potential interactions when both vaccines are administered in these populations. To address this gap, the MATabMATHics project investigates how Tdap and COVID-19 vaccines influence vaccine-induced antibody kinetics, as well as interactions between these vaccines. More specifically, serum samples from participants in the PREGCOVAC.BE trial were analyzed, in which pregnant and lactating women received a COVID-19 vaccine, and additionally received a Tdap vaccine during pregnancy (for lactating women, during pregnancy preceding the lactation period).
In order to study the dynamics of vaccine-induced antibodies, a conditional linear mixed modeling approach has been adopted. We modeled SARS-CoV-2- and Tdap-specific antibodies individually, yielding two pathogen-specific modeling frameworks accommodating different vaccination schedules (i.e., three vaccine doses for SARS-CoV-2 and one dose for Tdap), recorded prior and breakthrough COVID-19 infections, and including the timing of vaccination with the other vaccine as a conditional factor.
The linear mixed model was implemented as a distributional regression model in GAMLSS (Generalized Additive Model for Location, Scale, and Shape). This approach allowed us to address left censoring due to lower limits of detection and to account for observed heteroscedasticity at the distributional level using variance modeling. The impact of (conditional) fixed effects was analyzed using conditional means.
The two modeling frameworks, which were implemented for the SARS-CoV-2-specific RBD-IgG and the Tdap-specific PT antibodies, suggest that administrating one vaccine in temporal proximity to the other may influence antibody kinetics, potentially resulting in lower antibody levels.
96432311208