Israel Medical Association Journal

Background: Data are scarce on the immunogenicity of coronavirus disease 2019 vaccines in patients with autoimmune rheumatic diseases (ARD).

Objectives: To measure the immunoglobulin G (IgG) response after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunization and to evaluate clinical characteristics associated with seropositivity.

Methods: Samples were collected after the second and third doses of the three different types of vaccines in ARD patients. Seroconversion rates and IgG antibody S1/S2 titers were measured.

Results: The type of ARD diagnosis and previous treatment had no significant impact on the serum IgG antibody levels measured after the second (P = 0.489 and P = 0.330, respectively) and boost dose (P = 0.441 and P = 0.446, respectively). What made a significant difference regarding serum IgG antibody levels after the second dose was the type of SARS-CoV-2 vaccine. The difference was highly statistically significant for all vaccine types (P = 0.001 with the highest odds ratio for the mRNA vaccine). After the boost with the mRNA vaccine, all patients achieved a high level of serum IgG antibody levels (t = 10.31, P = 0.001). No ARD patients experienced serious post-vaccinal reactions. Eight patients developed COVID-19 before the boost dose.

Conclusions: In ARDs patients, the highest level of serum IgG antibody against S1/S2 proteins was achieved with the mRNA vaccine, irrespective of the therapy applied or the type of the disease. We recommend a booster dose with mRNA vaccine in all ARDs for the highest SARS-CoV-2 protection without serious post-vaccinal reactions observed.

Despite the very high benefit-to-risk ratio of vaccines, the fear of negative side effects has discouraged many people from getting vaccinated, resulting in the reemergence of previously controlled diseases such as measles, pertussis and diphtheria. This fear has been amplified more recently by multiple epidemiologic studies that confirmed the link of an AS03-adjuvanted pandemic influenza vaccine (Pandemrix®, GlaxoSmithKline Biologicals, Germany) used in Europe during the 2009 H1N1 influenza pandemic [A(H1N1)pdm09] with the development of narcolepsy, a chronic sleep disorder, in children and adolescents. However, public misperceptions of what adjuvants are and why they are used in vaccines has created in some individuals a closed “black box” attitude towards all vaccines. The focus of this review article is to revisit this “black box” using the example of narcolepsy associated with the European AS03-adjuvanted pandemic influenza vaccine.