COVID-19 anti immunoglobulin G antibodies serum levels among health care workers post COVID -19 vaccination: A single center study.

Coronavirus disease 2019 (COVID-19) pandemic has urged the scientific community internationally to find answers in terms of therapeutics and vaccines to control the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The post vaccination immune response differs between individuals especially health care workers who are the first line of defense to combat this disease. Our aim was to measure levels of anti-IgG antibodies titer post COVID-19 vaccination among health care workers in Suez Canal University Hospital. The study included 141 healthcare workers. Of these, 54 were physicians, 80 nurses, 6 health service workers, and one security guard. We used the Roche Elecsys Anti-SARS-CoV-2 assay for serological detection of IgG. Seropositive was found in 96.5% of the participants, and 43.3% of them had evidence of the prior history of COVID-19 infection. The highest titers of IgG in sera were found in the youngest age groups (20 - <35) years with a mean of 335.1 U/ ml. Participants who received the Sinovac vaccine had the highest mean IgG titer, 354.6U/ml; followed by Sinopharm (mean 352.15 U/ml) then Pfizer and Moderna (311.7U/ml) and AstraZeneca vaccine had the least mean level (267.31U/ml). Fatigue was the most significant short side effect occurring with 34% of the participants. In conclusion, there was a significant rising in serum IgG titer post-vaccine, and better antibody response in those previously infected with COVID-19. The post-COVID-19 vaccine serum IgG titers were affected by age, prior history of COVID-19 infection, and type of vaccine while short side effects post-vaccination may be affected by age and type of the vaccine.

Variant RH alleles and Rh immunisation in patients with sickle cell disease.

BACKGROUND: Alloimmunisation is a major complication in patients with sickle cell disease (SCD) receiving red blood cell (RBC) transfusions and despite provision of Rh phenotyped RBC units, Rh antibodies still occur. These antibodies in patients positive for the corresponding Rh antigen are considered autoantibodies in many cases but variant RH alleles found in SCD patients can also contribute to Rh alloimmunisation. In this study, we characterised variant RH alleles in 31 SCD patients who made antibodies to Rh antigens despite antigen-positive status and evaluated the clinical significance of the antibodies produced. MATERIALS AND METHODS: RHD and RHCE BeadChip™ from BioArray Solutions and/or amplification and sequencing of exons were used to identify the RH variants. The serological features of all Rh antibodies in antigen-positive patients were analysed and the clinical significance of the antibodies was evaluated by retrospective analysis of the haemoglobin (Hb) levels before and after transfusion; the change from baseline pre-transfusion Hb and the percentage of HbS were also determined. RESULTS: We identified variant RH alleles in 31/48 (65%) of SCD patients with Rh antibodies. Molecular analyses revealed the presence of partial RHD alleles and variant RHCE alleles associated with altered C and e antigens. Five patients were compound heterozygotes for RHD and RHCE variants. Retrospective analysis showed that 42% of antibodies produced by the patients with RH variants were involved in delayed haemolytic transfusion reactions or decreased survival of transfused RBC. DISCUSSION: In this study, we found that Rh antibodies in SCD patients with RH variants can be clinically significant and, therefore, matching patients based on RH variants should be considered.