Immunologic Responses to Single and Double Doses of COVID-19 Vaccines in Egyptians


The recent Coronavirus Disease 2019 (COVID-19), has caused a global pandemic, and development of safe, effective vaccines is mandatory to return back to pre pandemic life. Many vaccines have been developed and requested by the authorities after the emergency license issued. The main mechanism of protection is through humoral and cell-mediated immune responses that might reduce the potential for disease development or severity. Cytotoxic T cells clear virus-infected host cells and contribute to control of infection. Preliminary data are now available indicating safty and effecacy of different vaccines . The vaccines were tolerated, with induction of neutralizing antibodies and antigen-specific T cells against the SARS-CoV-2 spike protein. The aim of this work is to evaluate the immune responses in adults, aged 25-65 years, up to 8 weeks after vaccination with a single and double doses live inactivated (Sinopharm), mRNA (Pfizer/ Biontech) and viral vector (Oxford/AZ- ChAdOx1 nCoV-19) vaccines. The Th1- response ( interferon-γ and tumor necrosis factor-α cytokine secretion by CD4+ T cells) and antibody production predominantly of IgG1 and IgG3 subclasses as well as CD8+ T cells mono, polyfunctional and cytotoxic phenotypes, will be also measured.

Full Title of Study: “T Cell, Antibody and Cytokine Responses to Single and Double Doses of COVID-19 Vaccines in Egyptians”

Study Type

  • Study Type: Observational
  • Study Design
    • Time Perspective: Prospective
  • Study Primary Completion Date: June 1, 2021


  • Biological: COVID-19 Vaccines
    • different available vaccines: live inactivated, mRNA and viral vector vaccines

Arms, Groups and Cohorts

  • Vaccined group by live attenuated or viral vector or mRNA vaccine
    • Adults between 25-65 years old

Clinical Trial Outcome Measures

Primary Measures

  • measure immune cell activation induced by the vaccine
    • Time Frame: 8 weeks
    • estimate number of lymphocytes, T cells, Natural killer cells and B cells
  • measure antibody response to vaccines
    • Time Frame: 8 weeks
    • evaluation of IgG and IgM levels, mg/dl
  • measure the cytokine response to different vaccines
    • Time Frame: 8 weeks
    • level of IL-1, IL-2, TNF-alpha, IFN- gamma, My/dl

Participating in This Clinical Trial

Inclusion Criteria

  • healthy adults receiving COVID-19 vaccines Exclusion Criteria:

  • any contraindication of each COVID-19 vaccine as listed by WHO

Gender Eligibility: All

Minimum Age: 25 Years

Maximum Age: 65 Years

Are Healthy Volunteers Accepted: Accepts Healthy Volunteers

Investigator Details

  • Lead Sponsor
    • Assiut University
  • Provider of Information About this Clinical Study
    • Principal Investigator: Aliae AR Mohamed Hussein, Professor of Pulmonology – Assiut University

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