abatacept + vaccines

Abatacept + vaccines refers to the co-administration or interaction between abatacept, a selective T-cell costimulation modulator, and various vaccines. Abatacept is a recombinant fusion protein that inhibits T-cell activation by binding to CD80 and CD86 on antigen-presenting cells, thereby blocking their interaction with CD28 on T cells. This mechanism reduces immune responses and is used primarily in autoimmune diseases such as rheumatoid arthritis. When combined with vaccination (including inactivated or mRNA-based vaccines), abatacept has been shown to diminish antibody responses and reduce vaccine immunogenicity compared to healthy controls or patients not receiving abatacept[1][4][5]. The effect is most pronounced for certain vaccines (e.g., pneumococcal conjugate, SARS-CoV-2), where seroconversion rates and neutralizing antibody levels are lower in patients treated with abatacept[1][4][5]. Inactivated vaccines can generally be administered during therapy, but live attenuated vaccines are typically avoided due to immunosuppression risk[8].