Efficacy and Safety of Sinopharm Vaccine for SARS-CoV-2 and Breakthrough Infections in Iranian Patients with Hemoglobinopathies: A Preliminary Report

Background: The ongoing COVID-19 pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has led to high morbidity and mortality worldwide. Vaccination against SARS-CoV-2 is a leading strategy to change the course of the COVID-19 pandemic.

Aims Of The Study: Our aim was to investigate the efficacy and side effects of the Sinopharm vaccine in patients with hemoglobinopathies in Iran and the frequency of breakthrough infection after a full course of vaccination.

Methods: A multicenter cross-sectional study of 434 patients with hemoglobinopathies (303 β-thalassemia major, 118 β-thalassemia intermedia, and 13 sickle-thalassemia) were conducted from March to July 2021 in IRAN. All patients have received the first dose of the China Sinopharm vaccine and received the second dose of the vaccine 28 days apar.

Antibody Testing: Detection of immunity after vaccination was evaluated by commercial enzyme-linked immunosorbent assay (Pishtazteb ELISA commercial kit), including a surrogate virus neutralization test (sVNT), for detection of SARS-CoV-2 immunoglobulins (IgA, IgM, IgG), total neutralizing antibody (NAb).

Results: The mean age of patients was 35.0 ± 8.5 (from 18 to 70) years, and 55.6% were positive for the antibody. Overall, 48.2% of the studied population had at least one side effect after vaccination. The most frequent side effects were fever and chills, dizziness, and body pain. A total of 90 (20.7%) vaccinated patients developed breakthrough infections after two doses of Sinopharm vaccination. Disease severity was recorded, and it was classified as mild in 77.8%, moderate in 13.6%, and severe in 7.4% of patients. One 28-year-old woman with β-thalassemia major died eight days after diagnosing a breakthrough SARS-CoV-2 infection.

Conclusion: No safety concerns were identified in patients who received two doses of the Sinopharm vaccine. Its efficacy was not optimal due to the lack of effect on new variations of the virus. However, our data show that it seems to be protective against the severity of COVID-19 infection in patients with hemoglobinopathies. The frequency of breakthrough infections after two doses of Sinopharm vaccination supports the evolving dynamic of SARS-CoV-2 variants requiring special challenge since such infection may represent a risk for vulnerable patients.