(HealthDay News) — About one in five immunosuppressed individuals have no detectable immunoglobulin (Ig)G anti-spike antibodies, even after three or more COVID-19 vaccines, according to a study published in the August issue of The Lancet Rheumatology.

Fiona A. Pearce, PhD, from the University of Nottingham in the United Kingdom, and colleagues examined the association between seropositivity to the SARS-CoV-2 spike protein with demographic, disease and treatment-related characteristics after at least three COVID-19 vaccines in participants with rare autoimmune rheumatic diseases, participants with lymphoid malignancies and recipients of solid organ transplants.

A total of 28,411 individuals were recruited to the study; 81.1% provided serological data. Of those patients, 28.6, 61.8 and 9.6% had received three, four and five or more vaccine doses, respectively. The researchers found that IgG anti-spike antibodies were undetectable in 23.3, 14.1 and 20.7% of patients with solid organ transplants, those with rare autoimmune rheumatic diseases, and patients with lymphoid malignancies, respectively. Seropositivity was associated with younger age, a higher number of vaccine doses, and previous COVID-19 in all groups. The likelihood of seropositivity was reduced with immunosuppressive medication; the odds of seropositivity were lowest for solid organ transplant recipients receiving a combination of an antiproliferative agent, a calcineurin inhibitor, and steroids and those with rare autoimmune rheumatic diseases or lymphoid malignancies treated with anti-CD20 therapies.

“Our data also support the continued uptake of boosters in patients who are immunosuppressed, with seroconversion rates increasing with sequential vaccine doses,” the authors write.

Several authors disclosed ties to the pharmaceutical industry.

Abstract/Full Text