A Single Dose of COVID-19 mRNA Vaccine Induces Airway Immunity in COVID-19 Convalescent Patients

Background: Mucosal antibodies can prevent virus entry and replication in mucosal epithelial cells and hence virus shedding. Preclinical and clinical studies have shown that a parenteral booster injection of a vaccine against a mucosal pathogen promotes stronger mucosal immune responses following prior infection compared to two injections of a parenteral vaccine. We investigated whether this was also the case for a COVID-19 mRNA vaccine. Methods: Twenty-three COVID-19 convalescent patients and 20 SARS-CoV-2-naive subjects were vaccinated with respectively one and two doses of the Pfizer-BioNTech COVID-19 RNA vaccine. Nasal Epithelial Lining Fluid (NELF) and plasma were collected before and after vaccination and assessed for Immunoglobulin (Ig)G and IgA to Spike and for their ability to inhibit the binding of Spike to its ACE-2 receptor. Blood was analyzed one week after vaccination for the number of Spike-specific Antibody Secreting Cells (ASCs) with a mucosal tropism. Results: In COVID-19 convalescent patients, a single dose of vaccine amplified pre-existing Spike-specific IgG and IgA antibody responses in both NELF and blood against both vaccine homologous and variant strains, including delta. These responses were associated with Spike-specific IgG and IgA ASCs with a mucosal tropism in blood. Nasal IgA and IgG antibody responses were lower in magnitude in SARS-CoV-2-naive subjects after two vaccine doses Conclusion: This study showed that a parenteral booster injection of a COVID-19 RNA vaccine promoted stronger mucosal immune responses in COVID-19 convalescent patients compared to SARS-CoV-2 naive subjects who had received a first vaccine dose.

Immune Memory Response After a Booster Injection of mRNA-1273 for Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2)

Rising breakthrough infections of coronavirus-2 (SARS-CoV-2) in previously immunized individuals has raised concerns for a potential booster to combat suspected waning immunity and new variants. In this study, participants immunized 6-8 months earlier with a primary series of two doses of 50 or 100 μg of mRNA-1273 were administered a booster injection of 50 μg of mRNA-1273. Neutralizing antibody levels at one month after the booster were 1.7-fold higher than those one-month post primary series second injection meeting the prespecified criteria for noninferiority, and indicating an immune memory response. The reactogenicity after the booster dose was similar to that after the second dose in the primary series of two doses of mRNA-1273 (50 or 100 μg) with no serious adverse events reported in the one-month follow-up period. These results demonstrate that a booster injection of mRNA-1273 in previously immunized individuals stimulated an immune response greater than the primary vaccination series.

Efficacy of Intraoperative Platelet-Rich Plasma Augmentation and Postoperative Platelet-Rich Plasma Booster Injection for Rotator Cuff Healing: A Randomized Controlled Clinical Trial

Background: Platelet-rich plasma (PRP) has been applied as an adjuvant treatment for arthroscopic rotator cuff repair (ARCR) to enhance rotator cuff healing. However, it remains debatable whether PRP enhances tendon-to-bone healing. Purpose: To assess the efficacy of intraoperative augmentation and postoperative injection of PRP that was prepared using the double-spin method and calcium activation without thrombin in patients with ARCR. Study Design: Randomized controlled trial; Level of evidence, 1; and cohort study; Level of evidence, 3. Methods: A total of 58 patients underwent ARCR using intraoperative PRP augmentation. Half of the patients were randomly assigned to receive an additional ultrasound-guided PRP injection at the repair site at 2 weeks postoperatively (PRP-booster group); the other half did not receive the booster injection (PRP-only group). A control group that did not receive any PRP treatment was retrospectively matched using propensity score matching. Structural integrity was assessed using magnetic resonance imaging at 1 year postoperatively, and healing rates were compared between patients with tear sizes ≤2 cm versus >2 cm. Functional outcomes were assessed using the visual analog scale (VAS) for pain; VAS for satisfaction; shoulder range of motion; and Constant, American Shoulder and Elbow Surgeons, and Simple Shoulder Test scores at minimum 2-year follow-up. Results: In patients with tears >2 cm, the rate of healing failure at 1-year follow-up was significantly less in the overall PRP group than in the control group (12.9% vs 35.7%, respectively; P = .040), however, the PRP-booster group did not present a better healing rate than did the PRP-only group. The overall PRP group had lower VAS for pain scores compared with the control group (0.5 ± 1.1 vs 1.3 ± 1.8, respectively; P = .016) and higher VAS for satisfaction scores (9.2 ± 1.2 vs 8.6 ± 1.7; P = .023) at the final follow-up, whereas no statistical difference was found between the PRP-only and PRP-booster groups in functional outcomes. Conclusion: Intraoperative PRP augmentation during ARCR demonstrated superior anatomic healing results in patients with rotator cuff tears >2 cm as well as reduced pain and increased subjective satisfaction. PRP booster injection provided no additional benefit to tendon integrity or functional recovery.

Production of monoclonal antibodies to immunogenic peptides of ω-glaidin/c-hordein and rye-secalin for gluten free food screening

Introduction: The ω-glaidin/c-hordein (QPFPQPEQPFPW) and rye-secalin (QPFPQPQQPIPQ) peptides have previously demonstrated immunogenicity in sensitised coeliac T cell lines. The development of monoclonal antibody to those immunogenic peptides is presented with a view of developing an improved enzyme linked immunosorbent assay (ELISA) as a reliable tool to screen the safety of foods specialised for coeliac disease (CD) patients. Methods: Balb/C mice were fed with gluten free food. The immunogens were conjugated to purified tuberculin protein derivative (PPD) with glutaraldehyde and emulsified in Freund’s adjuvant. The employed immunization schedule included 3-5 weeks intervals, followed by a final intravenous injection without adjuvant, 3-4 days prior to fusion. Results: The antibody produced was IgM rather than IgG, although the hybridoma was successfully generated. The IgM class antibody is known to be relatively unstable, so could not be used in kits designed for food screening. Conclusions: The immunogenic peptides could possibly be used to raise monoclonal antibodies for gluten screening. However, a single booster injection might be insufficient to stimulate the spleen directly or the mice should be immunized with higher concentration of immunogen. This could be improved by including multiple booster administrations and increasing the dose.

Synthetic Peptides as Immunogen in the Production of IgY Anti-C-Myc Antibody in Local Chicken (Gallus gallus)

Experiments conducted to determine the effect of doses of immunogen on the levels of IgY c-Myc antibody in chickens. To generate antibody, we used a synthetic peptide as an immunogen, which is developed from the epitope of the c-Myc protein. Hens were immunized a week after their first eggs were produced. Antigen diluted in double distilled water and emulsified with Freund 's Complete Adjuvant. The suspension was injected into the area of the chicken breast subcutaneously with a dose of 0, 0.02, 0.04, 0.06, 0.08, 0.1, 0.12, 0.14, or 0.16 mg per hen. Booster injection performed on days 10, 20, and 30 with the same volume of emulsion, but using Incomplete Freund 's Adjuvant and the amount of antigen was half of the amount of the first Immunization. Extraction of IgY from eggs was carried out using kits from Gallus Immunotech. The level of IgY was quantified using a spectrophotometer where the absorbance was read at 280 nm. The results showed that after the first immunization IgY content of the egg were reached the level of >5 mg/ml yolk when the dose of immunogen was above 0.1 mg/hen. The level was higher in eggs produced after the third booster ( >8 mg/ml yolk), but it is lower in all groups treated with immunogen above 0.1 mg/hen. We concluded, immunogen dosage of 0.1 mg/hen was optimum in the production of chicken IgY anti-c-Myc.

Synthetic Peptides as Immunogen in the Production of IgY Anti-C-Myc Antibody in Local Chicken (Gallus Gallus)

Experiments conducted to determine the effect of doses of immunogen on the levels of IgY c-Myc antibody in chickens. To generate antibody, we used a synthetic peptide as an immunogen, which is developed from the epitope of the c-Myc protein. Hens were immunized a week after their first eggs were produced. Antigen diluted in double distilled water and emulsified with Freund 's Complete Adjuvant. The suspension was injected into the area of the chicken breast subcutaneously with a dose of 0, 0.02, 0.04, 0.06, 0.08, 0.1, 0.12, 0.14, or 0.16 mg per hen. Booster injection performed on days 10, 20, and 30 with the same volume of emulsion, but using Incomplete Freund 's Adjuvant and the amount of antigen was half of the amount of the first Immunization. Extraction of IgY from eggs was carried out using kits from Gallus Immunotech. The level of IgY was quantified using a spectrophotometer where the absorbance was read at 280 nm. The results showed that after the first immunization IgY content of the egg were reached the level of >5 mg/ml yolk when the dose of immunogen was above 0.1 mg/hen. The level was higher in eggs produced after the third booster ( >8 mg/ml yolk), but it is lower in all groups treated with immunogen above 0.1 mg/hen. We concluded, immunogen dosage of 0.1 mg/hen was optimum in the production of chicken IgY anti-c-Myc.

Immunisation of Labeo rohita with Antigenic preparation of Aphanomyces invadans

Aphanomyces invadans is an important fungal pathogen infecting freshwater and brackishwater fishes. In the present study, an attempt has been made to determine the effect of immunisation in Labeo rohita advanced fingerlings against A. invadans infection. The efficacy of the immunisation was evaluated by challenge with A. invadans as well as quantification of antibody level by ELISA. Following an initial immunisation in conjunction with adjuvant, the fish were given a booster dose after 35 days. After 14 and 28 days of the booster injection, blood was collected from the immunised rohu for monitoring the antibody level. The fish were also challenged with A. invadans zoospores to determine the relative percent survival. The immunised fish had significantly higher antibody level after 14 days of booster injection as compared to the control fish. However, the antibody level after 28 days of booster injection was not significantly different from the control fish. More importantly, similar to control fish, 100% mortality was observed in the immunised fish challenged after 14 and 28 days of booster immunisation. Therefore, it can be concluded that it may not be suitable to induce protective immunity following immunisation with conventional antigenic preparations.