A single dose ChAdOx1 nCoV-19 vaccine elicits high antibody responses in individuals with prior SARS-CoV-2 infection comparable to that of double dose vaccinated SARS-CoV-2 infection naïve individuals

Background A single dose COVID-19 vaccines, mostly mRNA-based vaccines, are shown to induce robust antibody responses in individuals who were previously infected with SARS-CoV-2, suggesting the sufficiency of a single dose to those individuals. However, these important data are limited to developed nations and lacking in resource-limited countries, like Ethiopia. Methods We compared receptor-binding domain (RBD)-specific IgG antibodies in 40 SARS-CoV-2 naïve participants and 25 participants previously infected with SARS-CoV-2, who received two doses of ChAdOx1 nCoV-19 vaccine. We measured the antibody response in post-vaccination blood samples from both groups of participants collected at four different post-vaccination time points: 8- and 12-weeks after each dose of the vaccine administration using an in-house developed ELISA. Results We observed a high level of anti-RBD IgG antibodies titers 8-weeks after a single dose administration (16/27; 59.3%) among naïve participants, albeit dropped significantly (p<0.05) two months later, suggesting the protective immunity elicited by the first dose ChAdOx1 nCoV-19 vaccine will likely last for a minimum of three months. However, as expected, a significant (p<0.001) increase in the level of anti-RBD IgG antibodies titers was observed after the second dose administration in all naïve participants. By contrast, the ChAdOx1 nCoV-19 vaccine-induced anti-RBD IgG antibody titers produced by the P.I participants at 8- to 12-weeks post-single dose vaccination were found to be similar to the antibody titers seen after a two-dose vaccination course among infection- naïve participants and showed no significant (p>0.05) increment following the second dose administration. Conclusion Taken together, our findings show that a single ChAdOx1 nCoV-19 dose in previously SARS-CoV-2 infected individuals elicits similar antibody responses to that of double dose vaccinated naïve individuals. Age and sex were not associated with the level of vaccine-elicited immune responses in both individuals with and without prior SARS-CoV-2 infection. Further studies are required to assess the need for a booster dose to extend the duration and amplitude of the specific protective immune response in Ethiopia settings, especially following the Omicron pandemic.

Microemulsion Based Nanostructures for Drug Delivery

Most of the active pharmaceutical compounds are often prone to display low bioavailability and biological degradation represents an important drawback. Due to the above, the development of a drug delivery system (DDS) that enables the introduction of a pharmaceutical compound through the body to achieve a therapeutic effect in a controlled manner is an expanding application. Henceforth, new strategies have been developed to control several parameters considered essential for enhancing delivery of drugs. Nanostructure synthesis by microemulsions (ME) consist of enclosing a substance within a wall material at the nanoscale level, allowing to control the size and surface area of the resulting particle. This nanotechnology has shown the importance on targeted drug delivery to improve their stability by protecting a bioactive compound from an adverse environment, enhanced bioavailability as well as controlled release. Thus, a lower dose administration could be achieved by minimizing systemic side effects and decreasing toxicity. This review will focus on describing the different biocompatible nanostructures synthesized by ME as controlled DDS for therapeutic purposes.

Ampicillin Plus Ceftriaxone Combined Therapy for Enterococcus faecalis Infective Endocarditis in OPAT

Ampicillin plus ceftriaxone (AC) is a well-recognized inpatient regimen for Enterococcus faecalis infective endocarditis (IE). In this regimen, ceftriaxone is usually administered 2 g every 2 h (AC12). The administration of AC in outpatient parenteral antibiotic treatment (OPAT) programs is challenging because multiple daily doses are required. AC regimens useful for OPAT programs include once-daily high-dose administration of ceftriaxone (AC24) or AC co-diluted and jointly administered in bolus every 4 h (ACjoined). In this retrospective analysis of prospectively collected cases, we aimed to assess the clinical effectivity and safety of three AC regimens for the treatment of E. faecalis IE. Fifty-nine patients were treated with AC combinations (AC12 n = 32, AC24 n = 17, and ACjoined n = 10). Six relapses occurred in the whole cohort: five (29.4%) treated with AC24 regimen and one (10.0%) with ACjoined. Patients were cured in 30 (93.3%), 16 (94.1%), and eight (80.0%) cases in the AC12, AC24 and ACjoined groups, respectively. Unplanned readmission occurred in eight (25.0%), six (35.3%), and two (20.0%) patients in the AC12, AC24 and ACjoined groups, respectively. The outcome of patients with E. faecalis IE treated with AC in OPAT programs relies on an optimization of the delivery of the combination. AC24 exhibit an unexpected rate of failures, however, ACjoined might be an effective alternative which clinical results should corroborate in further studies.

Magnitude and Breadth of Antibody Cross-reactivity Induced by Recombinant Influenza Hemagglutinin Trimer Vaccine Is Enhanced by Combination Adjuvants

The effects of adjuvants for increasing the immunogenicity of influenza vaccines are well known. However, the effect of adjuvants on increasing the breadth of cross-reactivity is less well understood. In this study we have performed a systematic screen of different toll-like receptor (TLR) agonists, with and without a squalene-in-water emulsion on the immunogenicity of a recombinant trimerized hemagglutinin (HA) vaccine in mice after single-dose administration. Antibody (Ab) cross-reactivity for other variants within and outside the immunizing subtype (homosubtypic and heterosubtypic cross-reactivity, respectively) was assessed using a protein microarray approach. Of all the formulations tested, a combination of CpG, MPLA and AddaVAX (termed “IVAX-1”) yielded the greatest breadth and magnitude of Ab responses, particularly against the HA1 region (which includes the variable head domain) of HA. Antigen-specific plasma cell labeling experiments show the components of IVAX-1 are synergistic. This adjuvant preferentially stimulates CD4 T cells to produce Th1>Th2 type (IgG2c>IgG1) antibodies and cytokine responses. Moreover, IVAX-1 induces identical homo- and heterosubtypic IgG and IgA cross-reactivity profiles when administered intranasally. Consistent with these observations, a single-cell transcriptomics analysis demonstrated significant increases in expression of IgG1, IgG2b and IgG2c genes of B cells in H5/IVAX-1 immunized mice relative to naïve mice, as well as significant increases in expression of the IFNg gene of both CD4 and CD8 T cells. These data support the use of adjuvants for enhancing the breath and durability of antibody responses of influenza virus vaccines.

Seroconversion following the first, second, and third dose of SARS-CoV-2 vaccines in immunocompromised population; A systematic review and meta-analysis

Background: Immunocompromised (IC) patients are at higher risk of more severe COVID-19 infections than the general population. Special considerations should be dedicated to such patients. We aimed to investigate the efficacy of COVID-19 vaccines based on the vaccine type and etiology as well as necessity of booster dose in this high-risk population.Materials and methods: We searched PubMed, Web of Science, and Scopus databases for observational studies published between June 1st, 2020, and September 1st, 2021, which investigated the seroconversion after COVID-19 vaccine administration in adult patients with IC conditions. For investigation of sources of heterogeneity, subgroup analysis and sensitivity analysis were conducted. Statistical analysis was performed using R software.Results: According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses, we included 81 articles in the meta-analysis. The overall crude prevalence of seroconversion after the first (n: 7,460), second (n: 13,181), and third (n: 909, all population were transplant patients with mRNA vaccine administration) dose administration was 26.17% (95% CI: 19.01%, 33.99%, I2= 97.1%), 57.11% (95% CI: 49.22%, 64.83%, I2= 98.4%), and 48.65% (95% CI: 34.63%, 62.79%, I2= 94.4%). Despite the relatively same immunogenicity of mRNA and vector-based vaccines after the first dose, the mRNA vaccines induced higher immunity after the second dose. Regarding the etiologic factor, transplant patients were less likely to develop immunity after both first and second dose rather than patients with malignancy (17.0% vs 37.0% after first dose, P=0.02; 38.3% vs 72.1% after second dose, P<0.001) or autoimmune disease (17.0% vs 36.4%, P=0.04; 38.3% vs 80.2%, P<0.001). To evaluate the efficacy of the third dose, we observed an increasing trend in transplant patients after the first (17.0%), second (38.3%), and third (48.6%) dose.Conclusion: The rising pattern of seroconversion after boosting tends to be promising. In this case, more attention should be devoted to transplant patients who possess the lowest response rate.

Quantitative assessment of the central versus peripheral effect of intravenous clonidine using baroreflex equilibrium diagrams

Clonidine is a first-generation central antihypertensive that reduces sympathetic nerve activity (SNA). Although clonidine also exerts peripheral vasoconstriction, the extent to which this vasoconstriction offsets the centrally mediated arterial pressure (AP)-lowering effect remains unknown. In anesthetized rats (n = 8), we examined SNA and AP responses to stepwise changes in carotid sinus pressure under control conditions and after intravenous low-dose (2 μg/kg) and high-dose clonidine (5 μg/kg). In the baroreflex equilibrium diagram analysis, the operating-point AP under the control condition was 115.2 (108.5–127.7) mmHg [median (25th–75th percentile range)]. While the operating-point AP after low-dose clonidine was not significantly different with or without the peripheral effect, the operating-point AP after high-dose clonidine was higher with the peripheral effect than without [81.3 (76.2–98.2) mmHg vs. 70.7 (57.7–96.9), P < 0.05]. The vasoconstrictive effect of clonidine partly offset the centrally mediated AP-lowering effect after high-dose administration.

Dose Administration Aid Service in Community Pharmacies: Characterization and Impact Assessment

Adherence to therapies is a primary determinant of treatment success. Lack of medication adherence is often associated with medical and psychosocial issues due to complications from underlying conditions and is an enormous waste of medical resources. Dose Administration Aid Service (DAAS) can be seen as part of the solution, allowing individual medicine doses to be organized according to the dosing schedule determined by the patient’s prescriber. The most recent systematic reviews admit the possibility of a positive impact of this service. In line with this background, the study reported in this paper aimed to characterize DAAS implementation in Portugal and understand the perceptions of pharmacists and owners of community pharmacies regarding the impact of DAAS, preferred methodology types, and State contribution. The study was guided by qualitative description methodology and reported using the consolidated criteria for reporting qualitative research (COREQ) checklist. Data were collected through semi-structured interviews with 18 pharmacists and/or owners of community pharmacies. Using qualitative content analysis, we identified categories that revealed that automated weekly methodology is the preferred methodology, because of its easiness of use and lower cost of preparation. However, the investment cost was felt to be too high by the participants considering the number of potential users for implementation in practice. Participants were also unanimous in recognizing that DAAS has a very positive impact in terms of safety and medication adherence, and the majority agreed that it also helped reduce medication waste. Implications of these findings for medication adherence are discussed.

Anti-Spike SARS-CoV-2 IgG Assessment with a Commercial Assay during a 4-Month Course after COVID-19 Vaccination

We intended to assess the humoral response induced by the Pfizer/BioNTech Comirnaty COVID-19 vaccine with commercially available immunoassays: anti-spike (S) IgG and IgM, and anti-nucleocapsid (N) IgG antibodies, over a 4-month course. One hundred subjects, including 15 COVID-19 convalescents, comprised the study cohort. The SARS-CoV-2 antibodies concentrations were measured on day 0′ and 10′, 20′, 30′, 60′, 90′, and 120′ after the first dose administration. Over the course of the study, 100% of the participants developed and sustained anti-SARS-CoV-2 S IgG antibodies. The highest concentration, exceeding the quantification range of the test (2080 BAU/mL), was reached by 67% of the subjects on day 30′. The concentration of the antibodies remained stable between days 30′ and 90′ but was followed by a significant decrease between days 90′ and 120′. The stronger and more persistent humoral response was noted for women. The COVID-19 convalescents developed higher antibody levels, particularly 10 days after the first Comirnaty dose. Twenty-three out of the eighty-five naïve vaccinees failed to develop a detectable IgM response. LIAISON® SARS-CoV-2 TrimericS IgG (DiaSorin S.p.A, Saluggia, Italy) may be useful in the assessment of the humoral response to the Comirnaty vaccine. In contrast, Abbott’s anti-S SARS-CoV-2 IgM has a limited utility in this context.