This is a summary, written by members of the CITF Secretariat, of:

Cheung MW, Dayam RM, Shapiro JR, Law JC, Chao GYC, Pereira D, Goetgebuer RL, Croitoru D, Stempak JM, Acheampong L, Rizwan S, Lee JD, Jacob L, Ganatra D, Law R, Rodriguez-Castellanos VE, Kern-Smith M, Delgado-Brand M, Mailhot G, Haroon N, Inman RD, Piguet V, Chandran V, Silverberg MS, Watts TH, Gingras AC. Third and Fourth Vaccine Doses Broaden and Prolong Immunity to SARS-CoV-2 in Adult Patients with Immune-Mediated Inflammatory Diseases. J Immunol. 2023 Jun 16:ji2300190. doi: 10.4049/jimmunol.2300190.

The results and/or conclusions contained in the research do not necessarily reflect the views of all CITF members.

A CITF-funded study, published in The Journal of Immunology, demonstrates that third and fourth doses of vaccine sustain and broaden immune responses to SARS-CoV-2 in adults with immune-mediated inflammatory diseases (IMIDs). These include inflammatory bowel disease, psoriasis, psoriatic arthritis, ankylosing spondylitis, and rheumatoid arthritis. The authors conclude that these findings support the recommendation for three- and four-dose primary series vaccine regimens in people with IMIDs. This study is a collaboration between CITF-funded researchers Drs. Vinod Chandran, Tania Watts, and Anne-Claude Gingras, and colleagues Drs. Vincent Piguet and Mark Silverberg (all University of Toronto).

Key findings:

  • Three to four months after a second vaccine dose, IMID patients had significantly reduced SARS-CoV-2 specific antibodies, neutralization, and T cell responses when compared to healthy controls. A third dose was critical for boosting these responses to levels similar to those in healthy controls.
  • IMID patients overall reached the same peak antibody responses as healthy controls after the third and fourth doses.
  • However, patients with IMIDs treated with anti-TNF therapy, especially patients with inflammatory bowel disease (IBD), consistently showed reduced RBD- and spike-specific antibody levels, compared to healthy controls or patients not treated with anti-TNF therapy. This held true from the first through to the fourth dose of vaccine.
  • Third and fourth doses of vaccine enhanced the duration of antibody responses to SARS-CoV-2 in IMID patients overall.
  • Third doses were found to be important in both healthy controls and IMID patients for reducing the decay of neutralization responses to all variants of SARS-CoV-2, thereby broadening neutralization activity. Fourth doses showed additional stabilizing effects in IMID patients.
  • T cell responses in IMID patients to the wild-type virus, as well as to the BA.1 and BA.5 Omicron subvariants, were largely equivalent after three vaccine doses. There were no differences observed among patients treated or not with anti-TNF therapy.

161 participants contributed 607 samples to the study over eight time points beginning in January 2021. They were diagnosed with one or more IMIDs, were either untreated or treated with maintenance immunosuppressive therapy, and received a SARS-CoV-2 mRNA vaccine. Healthy controls were included only up to three to four months after dose three. Most study subjects received the Pfizer vaccine. Age did not have significant effects on responses to vaccination among patients with IMIDs.