Intradermal Tozinameran for Patients With Immune-mediated Dermatologic Diseases

The standard intramuscular tozinameran is widely used as a COVID-19 vaccine booster dose, although the fractionated-dose intradermal route of the vaccine has emerged as a dose-sparing and cost-effective alternative. However, before implementing the intradermal vaccine in patients with immune-mediated dermatologic diseases, its immunogenicity should be confirmed, as many of them use long-term immunosuppressive medications, which may alter their immune responses to the vaccine. This prospective open-labelled single-blinded randomised-controlled parallel-grouped non-inferiority trial aims to determine non-inferiority in the immunogenicity of fractionated-dose intradermal tozinameran in comparison with the standard intramuscular tozinameran as the fourth COVID-19 vaccine dose in patients with immune-mediated dermatologic diseases and compare vaccine-related adverse effects between the two.

Inclusion criteria

• Aged equal to or more than 18 years
• Diagnosed with psoriasis or autoimmune bullous diseases
• Completed two-doses of the primary vaccine series and the third booster dose lasted for more than three months
• Agree to receive the fourth COVID-19 vaccine dose as tozinameran

Exclusion criteria

• History of previous COVID-19 infection
• Positive result of COVID-19 rapid antigen test (tested upon recruitment prior to vaccination)
• Uncontrolled disease activity
• Non-dermatologic immune-mediated diseases
• Congenital or acquired immunodeficiency syndrome
• Cancer
• Pregnant women
• Allergy to components of tozinameran
• Inability to give written informed consent to participate in the study