Evaluation of Antibody Response in Patients with Cancer Following Sinopharm Covid-19 Vaccine in 2021

COVID-19 is one of the biggest pathogens that mainly targets the human respiratory system. Among the preventive methods against contracting COVID-19, vaccination has had an important effect in preventing COVID-19 and is an essential component in prevention. Various vaccines were provided to prevent COVID-19, one of these vaccines was Sinopharm, which was used for cancer patients in Iran, so this study aimed to determine the antibody response following the injection of Sinopharm vaccine in cancer patients in Iran in 2021.

This cross-sectional study was conducted in 2021 on 74 patients with various types of cancers in Amol and Sari cities who received two doses of the Sinopharm vaccine. Subjects participated in the study after obtaining informed consent. Cancer patients who were referred to vaccination centers were asked to refer to the reference laboratory 4 to 6 weeks after the second dose if they wished to determine the antibody level. A 5 cc blood sample was taken 4-6 weeks after receiving the second dose of the vaccine, and then the serum was separated from the samples and stored at -20. The level of SARS-CoV-2 Neutralizing antibody, Anti-RBD, and Anti-Spike IgG were provided by Kit Eliza, Pishtaz Tab Company. The sensitivity and specificity of the kits used for neutralizing antibodies are 100% and 99% respectively, for Anti-RBD 98.4% and 97.7%, and Anti-Spike IgG 98.16% and 99.01% respectively. Finally, according to the instructions of the kit, neutralizing antibody values greater than 2.5 Mg/ml and optical absorption greater than 1.1 for RDB antibody and anti-spike antibody values greater than 8 RU/ml were considered positive.

The average age of the subjects was 57.1±11.7 years. In terms of gender distribution, 45 people (60.8%) were women. The neutralizing antibody status was positive in 41 people (55.4%). There was no significant relationship between the presence of neutralizing antibodies and gender (P=0.811) and age (P=0.443). Antibody against RDB antigen was positive in 31 people (41.9%). There was no significant relation between the presence of antibodies against RDB antigen with gender (P=0.091) and age (P=0.336). Antibody against Spike virus antigen was positive in 20 people (27%). A significant relationship was observed between the presence of antibodies against the Spike antigen and gender (P=0.008) and the proportion of women who produced antibodies against the Spike virus antigen was more than men, but there was no significant relationship between the presence of antibodies against the Spike gene and age (P=0.336).

The results of the present study showed that the vaccination of COVID-19 by Sinopharm in immunocompromised patients such as cancer patients can induce an antibody response, although the percentage is not high. Also, no significant relationship was observed between antibody production and age.