Vaccine Regimen Research Articles

A Population-Based Study of SARS-CoV-2 IgG Antibody Responses to Vaccination in Manitoba.

Understanding variables that influence antibody responses to COVID-19 vaccination within a population can provide valuable information on future vaccination strategies. In this population-based study, we examined the antibody responses to COVID-19 vaccination in Manitoba using residual serum specimens collected between January 2021 and March 2022 (n = 20,365). Samples were tested for spike and nucleocapsid IgG against SARS-CoV-2 using clinically validated assays. We assessed the impacts of multiple factors on post-vaccination antibody titres including type of vaccine, age, sex, geographic location, number of doses received, and timing of vaccination. Our investigation demonstrated that vaccination with one dose of Moderna mRNA-1273 elicited higher anti-spike IgG titres overall compared to Pfizer BNT162b2 vaccination, while one dose of Pfizer BNT162b2 followed by a second dose of Moderna mRNA-1273 exhibited higher titres than two doses of Pfizer BNT162b2 or Moderna mRNA-1273, irrespective of age. Age and time post-vaccination had considerable effects on antibody responses, with older age groups exhibiting lower anti-spike IgG titres than younger ages, and titres of those vaccinated with Pfizer BNT162b2 waning faster than those vaccinated with Moderna mRNA-1273 or a combination of Pfizer BNT162b2 and Moderna mRNA-1273. Antibody titres did not appear to be affected by sex or geographic location. Our results identify how factors such as age and type of vaccine can influence antibody responses to vaccination, and how antibody titres wane over time. This information highlights the importance of tailoring vaccine regimens to specific populations, especially those at increased risk of severe COVID-19 and can be used to inform future vaccination strategies, scheduling of booster doses, and public health measures.

Signal peptide exchange alters HIV-1 envelope antigenicity and immunogenicity.

HIV-1 envelope (Env) is the key target for antibodies (Abs) against the virus and thus an important HIV-1 vaccine component. Env is synthesized from a gp160 precursor with a signal peptide (SP) at its N-terminus. This study investigated the influence of the SP on Env antigenicity and immunogenicity. Env proteins from two HIV-1 isolates, AA05 and AC02, were analyzed as gp120 and gp160 in their native wild-type (WT) forms and as chimeras with swapped SPs (AA05-02 and AC02-05). The WT and chimeric Env were assessed for antigenicity and glycosylation using monoclonal antibodies (mAbs) and glycan probes. Immunogenicity was tested in mice using three vaccine types: gp120 protein, gp120 DNA+gp120 protein, and gp120 DNA+gp160 DNA. The recombinant AC02 gp120 protein was antigenically superior to AA05 as indicated by higher reactivity with most mAbs tested. When SPs were swapped, the antigenicity of the chimeric gp120s (AA05-02 and AC02-05) resembled that of the gp120s from which the SPs were derived; AA05-02 was similar to AC02 and vice versa. Glycan probe reactivity followed a similar pattern: AA05-02 and AC02 showed similar affinity to high-mannose specific mAbs and lectins. Interestingly, the antigenicity of gp160s showed an opposite pattern; membrane-bound gp160 expressed with the AA05 SP (AA05 and AC02-05) showed greater mAb binding than gp160 with the AC02 SP (AC02 and AA05-02). Mice immunized with gp120 protein showed that AA05-02 induced stronger cross-reactive binding Ab responses than AA05 WT, and AC02 elicited stronger responses than AC02-05, indicating AC02 SP enhanced gp120 immunogenicity. However, when DNA vaccines were included (gp120 DNA+gp120 protein and gp120 DNA+gp160 DNA), the use of heterologous SPs diminished the immunogenicity of the WT immunogens. Among the three vaccine regimens tested, only gp120 DNA+gp160 DNA immunization elicited low-level Tier 2 neutralizing Abs, with AA05 WT inducing Abs with greater neutralization capabilities than AA05-02. These data demonstrate that the SP can significantly impact the antigenicity and immunogenicity of HIV-1 Env proteins. Hence, while SP swapping is a common practice in constructing Env immunogens, this study highlights the importance of careful consideration of the effects of replacing native SPs on the immunogenicity of Env vaccines.

Safety and immunogenicity after a 30-month boost of a subtype C ALVAC-HIV (vCP2438) vaccine prime plus bivalent subtype C gp120/MF59 vaccine boost (HVTN 100): A phase 1–2 randomized double-blind placebo-controlled trial

Induction of broad, durable immune responses is a challenge in HIV vaccine development. HVTN 100 Part A administered subtype C-containing ALVAC-HIV at months 0 and 1, and ALVAC-HIV with bivalent subtype C gp120/MF59 at months 3, 6 and 12. As IgG binding antibody and T-cell responses were similar or greater at month 12.5 vs. month 6.5, but waned by month 18, we investigated vaccine-elicited immune responses after a month 30 boost in this study, HVTN 100 Part B. From 13 September 2017 to 7 August 2018, a subgroup of vaccinees was randomized to receive intramuscular injections of ALVAC+gp120/MF59 (n = 32) or gp120/MF59 alone (n = 31) and a subgroup of placebo recipients was administered placebo (n = 7) at month 30. Primary outcomes were safety, IgG binding antibodies (bAbs) to vaccine-specific and V1V2 Env proteins and vaccine-specific CD4+ T cells at month 30.5. Secondary outcomes included neutralizing and antibody dependent cellular cytotoxicity functions and durability at months 30 and 36. Both vaccine groups had an acceptable safety profile. There were no statistically significant differences in the occurrence or level of IgG bAbs between the vaccine boost groups for any vaccine-specific or V1V2 antigens. IgG responses were higher to vaccine-matched gp120 than to V1V2. The booster vaccination restored the magnitude-breadth IgG bAb response to V1V2 antigens at month 30.5. However, it rapidly waned by month 36. CD4+ T-cell response rates to the 3 vaccine-matched Env antigens for the combined vaccine groups ranged from 37% at month 30, boosted to as high as 91% at month 30.5, and waned by month 36 to as low as 44%, with no significant differences between the vaccine boost groups. Because these responses waned after 6 months, additional strategies may be needed to maintain the durability of prime-boost vaccine regimens and to generate these or other immune responses that confer protection. Trial registration: South African National Clinical Trials Register (SANCTR number: DOH—27-0215-4796) and ClinicalTrials.gov (NCT02404311).

Determinants of Rabies Post-Exposure Prophylaxis Completion in Sarawak

Objective: Rabies remains persistent in Sarawak despite efforts to control its spread. This study investigates the determinants of rabies post-exposure prophylaxis (PEP) completion among individuals in Sarawak that have been exposed to potential rabies transmission through animal bites.Material and Methods: A retrospective cohort study, using a universal sampling approach was employed, utilizing data from the Sarawak i-Bite System. Binary logistic regression was used to identify significant variables: a p-value<0.05 was considered as statistically significant.Results: The mean age of people having experienced animal bites was 38.1 (S.D.=22.4) years. Most were male (51.6%) and of Chinese ethnicity (37.2%). The predominant sites of animal bites were the upper (53%) and lower limbs (39.5%). Category 3 bite injuries and bites from fully confined pets were the most frequently reported (68.9% and 43.9%, respectively). In total 56.5% of the study population had a complete rabies vaccine regimen as post-exposure prophylaxis, while 5.4% had incomplete vaccinations, and 38% received no vaccination. The majority received treatment at government hospitals (59.1%). The significant determinants of rabies post-exposure prophylaxis completion in Sarawak were the Iban ethnicity (odd ratio (OR)=2.9, 95% confidence interval (CI):1.08-2.44, p-value=0.02), grade 3 bite (OR=3.9, 95% CI=,1.86-4.68, p-value<0.001), pet mixed with stray (OR=2.41, 95% CI=1.32-2.33, p-value<0.001), stray animals (OR=2.41, 95% CI=1.78-3.25, p-value,0.001) and treated in a government hospital (OR=0.63, 95% CI=0.47-0.83, p-value<0.001).Conclusion: This study reported that only 56.5% of patients completed the rabies PEP series. The important determinants of PEP completion status were found to be the Iban ethnicity, bite severity, category of animal, and place of treatment. These findings offer valuable insights to assist the Sarawak State Health Department in prioritizing strategies to enhance the compliance rate, with the ultimate goal of eliminating dog-mediated Rabies deaths by 2030.

Vaccine hesitancy among parents of children in their first two years of life.

Vaccine hesitancy is considered a primary cause of outbreaks of vaccine-preventable infectious diseases. The Austrian vaccination plan includes 24 vaccinations in the first 2 years of life, 12 for free and 12 subject to a fee. Since preterm babies are more susceptible to severe infections, immunization is a vital protection strategy. This study examines the routine immunization schedule recommended for children in Austria, the number of timely vaccinations, and the number of delayed and rejected vaccinations. Possible reasons for vaccination delays and rejection and potential influencing factors (preterm birth, COVID-19 pandemic, information sources) are also analyzed. We included children aged 2 to 5 years who presented to Vienna's largest pediatric center with an Austrian mother-child pass and spent the first 2 years of their lives in Austria. Data was collected using questionnaires about the vaccination status, parents' reasons for any rejections or delays in the recommended vaccination regimen, the impact of the COVID-19 pandemic on individuals' vaccination behavior, and child-specific influencing factors such as preterm birth and socioeconomic factors. 90% of the 150 study subjects follow the recommendations on routine vaccinations, while 40-62% accept vaccinations subject to a fee. Preterm infants received less fee-based (53%) as well as gratuitous (88%) vaccinations. While free vaccinations tend to be delayed, more fee based vaccinations are rejected. With free vaccinations, delays and refusals occur due to illness or missed appointments. In the case of fee- required vaccinations, however, fears of side effects are also one of the main reasons. Due to the COVID-19 pandemic, about a quarter of parents have become more skeptical about vaccines. However, the vaccination rate of premature babies is usually just below that of full-term babies. Physicians remain the most trustworthy source of information about vaccinations. Free vaccinations are more accepted by parents than fee based vaccinations. Preterm babies, which are a high risk group for vaccination preventable diseases, show a lower or delayed vaccination rate, which must be prevented through intensive doctor education. In addition, vaccination hesitancy changed during the COVID-19 pandemic, which needs to be addressed during the medical consultation.

Recent Advances of Nipah Virus Disease: Pathobiology to Treatment and Vaccine Advancement.

The zoonotic infection of the Nipah virus (NiV) has yet again appeared in 2023 in Kerala state, India. The virus, which has a mortality rate ranging from about 40 to 70%, has already infected India five times, the first being in 2001. The current infection is the sixth virus outbreak in the Indian population. In 1998, the first NiV infection was noted in one village in Malaysia. After that, outbreaks from other South and Southeast Asian countries have been reported periodically. It can spread between humans through contact with body fluids. Therefore, it is unlikely to generate a new pandemic. However, there is a considerable knowledge gap in the different areas of NiV. To date, no approved vaccines or treatments have been available.Tofulfilthe knowledge gap, the review article provided a detailed overview of the genome and genome-encoded proteins, epidemiology, transmission, pathobiology, immunobiology, diagnosis, prevention and control measures, therapeutics (monoclonal antibodies and drug molecules), and vaccine advancement of the emerging and deadly pathogen. The advanced information will help researchers todevelop safe and effective NiV vaccine and treatment regimens worldwide.

Infectious diseases and global security: Analysis of global control and vaccination strategies

Introduction: Given the recent experience with the COVID-19 vaccine campaign, an optimal global policy to control future pandemics and ensure infectious security globally is highly relevant. Objective: The study aims to determine the optimal vaccination strategy to reduce COVID-19 morbidity and mortality during a pandemic.Methods: A systematic search of studies on infectious disease control and vaccination strategies for the period 2000-2023 in PubMed, Scopus, Web of Science and Google Scholar databases using keywords was conducted for the review. Relevant publications, data extraction and systematisation were selected.Results: The findings of the analysis highlight the importance of integrated interventions in global vaccination strategies, including health systems strengthening, innovative technologies for outbreak detection and international collaboration. Vaccination, as an effective preventive measure, significantly reduces the spread of infectious diseases. Vaccination with different types of vaccines has been shown to improve immune response compared to the use of the same type of vaccine. This approach, where the first and second vaccine doses are different, may increase the effectiveness of the immune response.Conclusions: Studies confirm that vaccination reduces the number of cases and deaths, reducing the economic burden. A variety of vaccines, including mRNA, vector, and inactivated vaccines, provide high efficacy in preventing COVID-19 infection and mortality, especially when a heterologous vaccination regimen is used. This review identifies the most effective infectious disease control strategies for the development of global health recommendations

Development of novel multi-protein chimeric immunogens that protect against infection with the Lyme disease agent, Borreliella burgdorferi.

Lyme disease is the most common tick-borne disease in North America. A vaccine for use in humans is not available. Here, we detail the development of two chimeric vaccine antigens, BAF and Chv2M. BAF elicits Abs that target proteins and protein variants produced by Borreliella species in ticks (OspB and OspA) and mammals (FtlA/B). OspB serves as the backbone structure for the BAF chimeric. Two OspA221-240 epitope-containing domain (ECD) variants (#A1 and #A15) were inserted into a loop in OspB. The N-terminal region of the FtlA protein was joined to the C-terminus of the chimeric. The second chimeric, Chv2M, consists of L5 (loop 5) and H5 (helix 5) ECDs derived from diverse OspC proteins. Borreliella species produce OspC upon exposure to the bloodmeal and during early infection in mammals. Here, we demonstrate that BAF and Chv2M are potent immunogens that elicit Abs that bind to each component protein (FtlA, FtlB, OspB, and multiple OspA and OspC variants). Anti-BAF and anti-Chv2M Abs kill Borreliella burgdorferi strains through Ab-mediated complement-dependent and complement-independent mechanisms. Eighty percent (32/40) of mice that received a three-dose vaccine regimen were protected from infection with B. burgdorferi B31. Efficacy increased to 90% (18/20) when the amount of Chv2M was increased in the third vaccine dose. Readouts for infection were flaB PCR and seroconversion to VlsE. This study establishes proof of principle for a chimeric immunogen vaccine formulation that elicits Abs to multiple targets on the B. burgdorferi cell surface produced during tick and mammalian stages of the enzootic cycle.IMPORTANCELyme disease is a growing public health threat across parts of the Northern Hemisphere. Regions that can support sustained tick populations are expanding, and the incidence of tick-borne diseases is increasing. In light of the increasing risk of Lyme disease, effective preventive strategies are needed. Most vaccine development efforts have focused on outer surface protein A, a Borreliella burgdorferi protein produced only in ticks. Herein, we describe the development of a novel vaccine formulation consisting of two multivalent chimeric proteins that are immunogenic and elicit antibodies with bactericidal activity that target several cell surface proteins produced by the Lyme disease spirochetes in feeding ticks and mammals. In a broader sense, this study advances efforts to develop custom-designed vaccinogens comprised of epitope-containing domains from multiple proteins.

Sequential immunization with chimeric hemagglutinin ΔNS1 attenuated influenza vaccines induces broad humoral and cellular immunity

Influenza viruses pose a threat to public health as evidenced by severe morbidity and mortality in humans on a yearly basis. Given the constant changes in the viral glycoproteins owing to antigenic drift, seasonal influenza vaccines need to be updated periodically and effectiveness often drops due to mismatches between vaccine and circulating strains. In addition, seasonal influenza vaccines are not protective against antigenically shifted influenza viruses with pandemic potential. Here, we have developed a highly immunogenic vaccination regimen based on live-attenuated influenza vaccines (LAIVs) comprised of an attenuated virus backbone lacking non-structural protein 1 (ΔNS1), the primary host interferon antagonist of influenza viruses, with chimeric hemagglutinins (cHA) composed of exotic avian head domains with a highly conserved stalk domain, to redirect the humoral response towards the HA stalk. In this study, we showed that cHA-LAIV vaccines induce robust serum and mucosal responses against group 1 stalk and confer antibody-dependent cell cytotoxicity activity. Mice that intranasally received cH8/1-ΔNS1 followed by a cH11/1-ΔNS1 heterologous booster had robust humoral responses for influenza A virus group 1 HAs and were protected from seasonal H1N1 influenza virus and heterologous highly pathogenic avian H5N1 lethal challenges. When compared with mice immunized with the standard of care or cold-adapted cHA-LAIV, cHA-ΔNS1 immunized mice had robust antigen-specific CD8+ T-cell responses which also correlated with markedly reduced lung pathology post-challenge. These observations support the development of a trivalent universal influenza vaccine for the protection against group 1 and group 2 influenza A viruses and influenza B viruses.

Evaluation of commercial quadrivalent foot-and-mouth disease vaccines against east African virus strains reveals limited immunogenicity and duration of protection

Foot-and-mouth disease virus (FMDV) causes a contagious disease (FMD) in cloven-hoofed animals. For FMD-endemic countries, vaccination is critical for controlling disease but is rarely monitored, despite substantial funds spent on vaccine purchases. We evaluated antibody responses in cattle to two commercial vaccines each containing antigens of four FMDV serotypes. Sampling was done over 360 days, with serology for each serotype performed using commercially available solid phase competition ELISAs (SPCE) and with virus neutralization tests (VNT) employing regionally relevant test viruses. A primary course of each vaccine was administered to 37 calves, some of which received a second dose after 28 days. Using new production batches of vaccines, all calves received a booster vaccination 180 days post vaccination, while 10 additional naïve calves were also vaccinated using the new batches and followed up for ∼180 days. Simple and general linear models were used to compare antibody responses which varied substantially according to vaccine, dose regime, serotype, and test, but were mostly insufficient to ensure a high likelihood of adequate or sustained probable protection. One of the vaccines administered as a two-dose primary course of vaccination was superior to other options, but even then, data trajectories from VNT responses suggested probable protection of 75 % of calves for 6 months for only one virus serotype. Calves administered with the other vaccine and those given a single primary dose developed low levels of antibodies, offering predicted likely protection lasting less than two months. Individual SPCE results were weakly correlated (r2 = 0.48) to neutralization and associated likelihoods of protection but SPCE and VNT agreed on which vaccine and dose regime performed best. Our findings highlight gaps in immunogenicity of FMD vaccines used in East Africa and reinforce the importance of independent quality control studies to evaluate and improve commercial FMD vaccines and vaccination regimes.

Genomic insights into mRNA COVID-19 vaccines efficacy: Linking genetic polymorphisms to waning immunity

ABSTRACT Genetic polymorphisms have been linked to the differential waning of vaccine-induced immunity against COVID-19 following vaccination. Despite this, evidence on the mechanisms behind this waning and its implications for vaccination policy remains limited. We hypothesize that specific gene variants may modulate the development of vaccine-initiated immunity, leading to impaired immune function. This study investigates genetic determinants influencing the sustainability of immunity post-mRNA vaccination through a genome-wide association study (GWAS). Utilizing a hospital-based, test negative case-control design, we enrolled 1,119 participants from the Taiwan Precision Medicine Initiative (TPMI) cohort, all of whom completed a full mRNA COVID-19 vaccination regimen and underwent PCR testing during the Omicron outbreak. Participants were classified into breakthrough and protected groups based on PCR results. Genetic samples were analyzed using SNP arrays with rigorous quality control. Cox regression identified significant single nucleotide polymorphisms (SNPs) associated with breakthrough infections, affecting 743 genes involved in processes such as antigenic protein translation, B cell activation, and T cell function. Key genes identified include CD247, TRPV1, MYH9, CCL16, and RPTOR, which are vital for immune responses. Polygenic risk score (PRS) analysis revealed that individuals with higher PRS are at greater risk of breakthrough infections post-vaccination, demonstrating a high predictability (AUC = 0.787) in validating population. This finding confirms the significant influence of genetic variations on the durability of immune responses and vaccine effectiveness. This study highlights the importance of considering genetic polymorphisms in evaluating vaccine-induced immunity and proposes potential personalized vaccination strategies by tailoring regimens to individual genetic profiles.

Real-world data on tolerability of COVID-19 vaccination in patients with rheumatoid arthritis based on patient-reported outcomes.

To assess tolerability of COVID-19 vaccination in patients with RA and controls based on patient-reported outcomes (PROs). In total, 266 study participants were included at 6 ± 1 weeks after their second vaccination (BioNTech/Pfizer (72.2%), AstraZeneca (18.8%) and Moderna (9.0%)). In a cross-sectional, observational study design, PRO data were recorded regarding both total and symptom-level tolerability. Overall tolerability was very high according to the patients' self-assessment scores (1.71 for the first and 1.72 for the second vaccination, 6-point Likert scale [1 (very good) to 6 (very poor)]) and did not differ significantly between patients with RA (n = 204) and controls (n = 62). Self-rated overall tolerability regarding first vaccination was significantly better (P = 0.002) in patients receiving mRNA vaccines (n = 193, mean tolerability 1.59) as compared with vector-vaccinated patients (n = 73, mean tolerability 2.04). Homologous or heterologous vaccination regimens had no statistically significant effect on vaccine tolerability (P = 0.131). Reservations about the vaccination were rare (6.4% for the first and 6.0% for the second vaccination) but significantly associated with poorer overall tolerability (P < 0.001) and significantly reduced willingness to recommend vaccination to others (P < 0.001 for the first and P = 0.004 for the second vaccination). Based on these real-world data, tolerability of COVID-19 vaccination was very good in both RA patients and controls. Reservations against COVID-19 vaccination were rare overall, but if present, associated with a significantly worse tolerability and a significantly lower degree of recommendation.

Long-term cellular immunity of vaccines for Zaire Ebola Virus Diseases

Recent Ebola outbreaks underscore the importance of continuous prevention and disease control efforts. Authorized vaccines include Merck’s Ervebo (rVSV-ZEBOV) and Johnson & Johnson’s two-dose combination (Ad26.ZEBOV/MVA-BN-Filo). Here, in a five-year follow-up of the PREVAC randomized trial (NCT02876328), we report the results of the immunology ancillary study of the trial. The primary endpoint is to evaluate long-term memory T-cell responses induced by three vaccine regimens: Ad26–MVA, rVSV, and rVSV–booster. Polyfunctional EBOV-specific CD4+ T-cell responses increase after Ad26 priming and are further boosted by MVA, whereas minimal responses are observed in the rVSV groups, declining after one year. In-vitro expansion for eight days show sustained EBOV-specific T-cell responses for up to 60 months post-prime vaccination with both Ad26-MVA and rVSV, with no decline. Cytokine production analysis identify shared biomarkers between the Ad26-MVA and rVSV groups. In secondary endpoint, we observed an elevation of pro-inflammatory cytokines at Day 7 in the rVSV group. Finally, we establish a correlation between EBOV-specific T-cell responses and anti-EBOV IgG responses. Our findings can guide booster vaccination recommendations and help identify populations likely to benefit from revaccination.

Beta Spike-Presenting SARS-CoV-2 Virus-like Particle Vaccine Confers Broad Protection against Other VOCs in Mice.

Virus-like particles (VLPs) are non-infectious and serve as promising vaccine platforms because they mimic the membrane-embedded conformations of fusion glycoproteins on native viruses. Here, we employed SARS-CoV-2 VLPs (SMEN) presenting ancestral, Beta, or Omicron spikes to identify the variant spike that elicits potent and cross-protective immune responses in the highly sensitive K18-hACE2 challenge mouse model. A combined intranasal and intramuscular SMEN vaccine regimen generated the most effective immune responses to significantly reduce disease burden. Protection was primarily mediated by antibodies, with minor but distinct contributions from T cells in reducing virus spread and inflammation. Immunization with SMEN carrying ancestral spike resulted in 100, 75, or 0% protection against ancestral, Delta, or Beta variant-induced mortality, respectively. However, SMEN with an Omicron spike provided only limited protection against ancestral (50%), Delta (0%), and Beta (25%) challenges. By contrast, SMEN with Beta spikes offered 100% protection against the variants used in this study. Thus, the Beta variant not only overcame the immunity produced by other variants, but the Beta spike also elicited diverse and effective humoral immune responses. Our findings suggest that leveraging the Beta variant spike protein can enhance SARS-CoV-2 immunity, potentially leading to a more comprehensive vaccine against emerging variants.

Comparison of Adverse Events and Antibody Responses Among Different COVID-19 Vaccination Schedules.

Global investment in developing COVID-19 vaccines has been substantial, but vaccine hesitancy has emerged due to misinformation. Concerns about adverse events, vaccine shortages, dosing confusion, mixing vaccines, and access issues contribute to hesitancy. Initially, the WHO recommended homologous vaccination (same vaccine for both doses), but evolving factors led to consideration of heterologous vaccination (different vaccines). The study compared reactogenicity and antibody response for both viral protein spike (S) and nucleocapsid (N) in 205 participants who received three vaccination regimens: same vaccine for all doses (Pfizer), two initial doses of the same vaccine (CoronaVac or AstraZeneca), and a Pfizer booster. ChAdOx1 and BNT162b2 vaccines were the most reactogenic vaccines, while CoronaVac vaccine was the least. ChAdOx1 and BNT162b2 achieved 100% of S-IgG seropositivity with one dose, while CoronaVac required two doses, emphasizing the importance of the second dose in achieving complete immunization across the population with different vaccine regimes. Pfizer recipients showed the highest S-IgG antibody titers, followed by AstraZeneca recipients, both after the first and second doses. A third vaccine dose was essential to boost the S-IgG antibodies and equalize the antibody levels among the different vaccine schedules. CoronaVac induced N-IgG antibodies, while in the Pfizer and AstraZeneca groups, they were induced by a natural infection, reinforcing the role of N protein as a biomarker of infection.

P.307: miRNA disparities in kidney transplant recipients: Responders vs. non-responders to the three-dose vaccine regimen.

P.307: miRNA disparities in kidney transplant recipients: Responders vs. non-responders to the three-dose vaccine regimen.

An alternative vaccination regime against strangles in sport horses

An alternative vaccination regime against strangles in sport horses

A two-dose regimen of Qβ virus-like particle-based vaccines elicit protective antibodies against heroin and fentanyl.

Opioid overdoses and the growing rate of opioid use disorder (OUD) are major public health concerns, particularly in the United States. Current treatment approaches for OUD have failed to slow the growth of the opioid crisis. Opioid vaccines have shown pre-clinical success in targeting multiple different opioid drugs. However, the need for many immunizations can limit their clinical implementation. In this study, we investigate the development of novel opioid vaccines by independently targeting fentanyl and the active metabolites of heroin using a bacteriophage virus-like particle (VLP) vaccine platform. We establish the successful conjugation of haptens to bacteriophage Qβ VLPs and demonstrate immunogenicity of Qβ-fentanyl, Qβ-morphine, and Qβ-6-acetylmorphine in animal models after one or two immunizations. We show that in independently or in combination, these vaccines elicit high-titer, high-avidity, and durable antibody responses. Moreover, we reveal their protective capacities against heroin or fentanyl challenge after two immunizations. Overall, these findings establish Qβ-VLP conjugated vaccines for heroin and fentanyl as very promising opioid vaccine candidates.

Non-HIV Vaccine-Induced Immune Responses as Potential Baseline Immunogenicity Predictors of ALVAC-HIV and AIDSVAX B/E-Induced Immune Responses.

Identifying correlations between immune responses elicited via HIV and non-HIV vaccines could aid the search for correlates of HIV protection and increase statistical power in HIV vaccine-efficacy trial designs. An exploratory objective of the HVTN 097 phase 1b trial was to assess whether immune responses [focusing on those supported as correlates of risk (CoR) of HIV acquisition] induced via the RV144 pox-prime HIV vaccine regimen correlated with those induced via tetanus toxoid (TT) and/or hepatitis B virus (HBV) vaccines. We measured TT-specific and HBV-specific IgG-binding antibody responses and TT-specific and HBV-specific CD4+ T-cell responses at multiple time points in HVTN 097 participants, and we assessed their correlations at peak time points with HIV vaccine (ALVAC-HIV and AIDSVAX B/E)-induced responses. Four correlations were significant [false discovery rate-adjusted p-value (FDR) ≤ 0.2]. Three of these four were with IgG-binding antibody responses to TT measured one month after TT receipt, with the strongest and most significant correlation [rho = 0.368 (95% CI: 0.096, 0.588; p = 0.008; FDR = 0.137)] being with IgG-binding antibody responses to MN gp120 gDneg (B protein boost) measured two weeks after the second ALVAC-HIV and AIDSVAX B/E boost. The fourth significant correlation [(rho = 0.361; 95% CI: 0.049, 0.609; p = 0.021; FDR = 0.137)] was between CD4+ T-cell responses to a hepatitis B surface antigen peptide pool, measured 2 weeks after the third HBV vaccination, and IgG-binding antibody responses to gp70BCaseAV1V2 (B V1V2 immune correlate), measured two weeks after the second ALVAC-HIV and AIDSVAX B/E boost. These moderate correlations imply that either vaccine, TT or HBV, could potentially provide a moderately useful immunogenicity predictor for the ALVAC-HIV and AIDSVAX B/E HIV vaccine regimen.

A retrospective survey on the effectiveness of vaccines administered to individuals in China with regard to inactivated COVID-19 vaccines, Ad5-nCoV and/or aerosolized Ad5-nCoV

ABSTRACT We administered a questionnaire to participants who received different vaccination regimens to evaluate the effectiveness of Ad5-vectored COVID-19 vaccines. The results showed that administration of intramuscular Ad5-nCoV provided 21.32% more protection against SARS-CoV-2 infection than that of the inactivated COVID-19 vaccine in people who had received only one type of COVID-19 vaccine. Furthermore, aerosolized Ad5-nCoV exhibited good protection, whether it was administered as a homologous booster to people vaccinated with the intramuscular Ad5-nCoV or as a heterologous booster to people vaccinated with inactivated COVID-19 vaccines. Our research indicates that Ad5-nCoV is an effective booster. This finding supports the future selection of COVID-19 immunization strategies.