Phenotypic Expression of Known and Novel Hemoglobin A2-Variants, Hemoglobin A2-Mae Phrik [Delta 52(D3) Asp > Gly, HBD:c.158A > G], Associated with Hemoglobin E [Beta 26(B8) Glu > Lys, HBB:c.79G > A] in Thailand

The interactions of δ-globin variants with α- and ß-thalassemia or other hemoglobinopathies cause complex thalassemic syndromes and potential diagnostic problems. Understanding the molecular basis and phenotypic expression is crucial. Four unrelated Thai subjects with second hemoglobin (Hb) A2 fractions were studied. A standard automated cell counter was used to acquire initial hematological data. Hb analysis was carried out by capillary electrophoresis (CE) and high-performance liquid chromatography (HPLC) assays. Globin gene mutations and haplotype were identified by appropriate DNA analysis. An allele-specific polymerase chain reaction method was developed to provide a simple molecular diagnostic test. Hb analysis revealed a Hb A2 variant in all cases. DNA analysis of the δ-globin gene identified the Hb A2-Melbourne [δ43(CD2)Glu > Lys] variant in combination with Hb E in three cases. Analysis of the remaining case identified a novel δ-Hb variant, namely Hb A2-Mae Phrik [δ52(D3)GAT > GGT; Asp > Gly], found in association with Hb E and α+-thalassemia, indicative of the as yet undescribed combination of triple heterozygosity of globin gene defects. An allele-specific PCR-based assay was successfully developed to identify this variant. The ß-haplotype of the Hb A2 Mae-Phrik allele was strongly associated with haplotype [+ − − − − ± +]. This study advanced our understanding of the phenotypic expression of known and novel δ-Hb variants coinherited with other globin gene defects, routinely causing problems with diagnosis. Therefore, knowledge and recognition of this Hb variant and molecular assessments are crucial to improving diagnosis.

Safety, tolerability, and antibody response after intradermal vaccination of PFE-BNT in adults who have completed two-doses of Verocell (inactivated vaccine).

INTRODUCTION: The necessity for an equal distribution of the COVID-19 vaccination is critical. Lower-middle and lower income countries may not be able to manufacture their vaccines, nor may they be able to afford to buy them for every inhabitant. Furthermore, the vaccination's potency may wane over time. A booster dosage is recommended. Despite this, certain areas or groups of people are still waiting for their first vaccine dosage. OBJECTIVES: The purposes of this study were to assess the safety and tolerability of patients who received a fractionated intradermal administration (ID) of PFE-BNT as a booster dose in a group of people who had previously finished full doses of Verocell and to determine the antibody response after the injection. METHODS: An open-label experiment was carried out. Participants were at least 18 years old. Participants received 6 ug of PFE-BNT vaccination through intradermal injection. The safety and adverse reactions were monitored at immediate after injection, 30 min later, day 1, day 7, and day 30. Venous blood tests for specific IgG concentration against SARS-CoV-2 spike S1 were received prior to injection and day 30. RESULTS: 42 participants completed the study. The mean age was 48 (the range; 23-62). The average duration after completing the 2nd dose of Verocell was 78.3 days (95% CI; 73.9-82.8). There was no serious adverse event. Almost 50% of participants reported minor adverse reactions on day 1 and roughly 30% still reporting on day 7. Systemic reactions were found less than 5%. The antibody level at day 30 was 16669.8 (95% CI; 3692.6-51238.9), which was 40 times higher. CONCLUSION: PFE-BNT at a dose of 6 ug (1/5 of the typical dose) was shown to be safe and well tolerated when given intradermally. The antibody reaction was very strong. The ID administration could potentially save vaccine doses.