SARS-CoV-2 Vaccine Responses in Individuals with Antibody Deficiency: Findings from the COV-AD Study

J Clin Immunol. 2022 Jul;42(5):923-934. doi: 10.1007/s10875-022-01231-7. Epub 2022 Apr 14.


Background: Vaccination prevents severe morbidity and mortality from COVID-19 in the general population. The immunogenicity and efficacy of SARS-CoV-2 vaccines in patients with antibody deficiency is poorly understood.

Objectives: COVID-19 in patients with antibody deficiency (COV-AD) is a multi-site UK study that aims to determine the immune response to SARS-CoV-2 infection and vaccination in patients with primary or secondary antibody deficiency, a population that suffers from severe and recurrent infection and does not respond well to vaccination.

Methods: Individuals on immunoglobulin replacement therapy or with an IgG less than 4 g/L receiving antibiotic prophylaxis were recruited from April 2021. Serological and cellular responses were determined using ELISA, live-virus neutralisation and interferon gamma release assays. SARS-CoV-2 infection and clearance were determined by PCR from serial nasopharyngeal swabs.

Results: A total of 5.6% (n = 320) of the cohort reported prior SARS-CoV-2 infection, but only 0.3% remained PCR positive on study entry. Seropositivity, following two doses of SARS-CoV-2 vaccination, was 54.8% (n = 168) compared with 100% of healthy controls (n = 205). The magnitude of the antibody response and its neutralising capacity were both significantly reduced compared to controls. Participants vaccinated with the Pfizer/BioNTech vaccine were more likely to be seropositive (65.7% vs. 48.0%, p = 0.03) and have higher antibody levels compared with the AstraZeneca vaccine (IgGAM ratio 3.73 vs. 2.39, p = 0.0003). T cell responses post vaccination was demonstrable in 46.2% of participants and were associated with better antibody responses but there was no difference between the two vaccines. Eleven vaccine-breakthrough infections have occurred to date, 10 of them in recipients of the AstraZeneca vaccine.

Conclusion: SARS-CoV-2 vaccines demonstrate reduced immunogenicity in patients with antibody deficiency with evidence of vaccine breakthrough infection.

Keywords: COVID-19; CVID; Inborn errors of immunity; Primary immunodeficiency; SARS-CoV-2; Secondary immunodeficiency; Vaccination.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Viral
  • COVID-19 Vaccines
  • COVID-19*
  • Humans
  • Primary Immunodeficiency Diseases*
  • SARS-CoV-2
  • Viral Vaccines*


  • Antibodies, Viral
  • COVID-19 Vaccines
  • Viral Vaccines