Clinical and Experimental Vaccine Research最新文献

Staphylococcus aureus-mediated human disease ranges from minor skin infection to life threatening diseases. In the past, infections caused by this bacterium could be treated with antibiotics. However, this species has become increasingly resistant to antibiotics. Therefore, vaccines as alternative therapeutic tools is urgently required for controlling this troubles pathogen. But thus far, all vaccines in human clinical trials for preventing S. aureus infections have failed. Three major reasons for this failure can be summarized: 1) An effective antigen has not yet been identified; 2) Host protective immune responses against S. aureus are unclear; 3) Good animal model is not yet identified. The most critical challenge is that despite robust serum immunoglobulin G titers, vaccinated hosts fail to eliminate intracellular S. aureus. To solve this problem, a vaccine inducing both humoral- and cellular-immunity should be designed and developed. Based on our research experiences and recent other groups' published data, we propose that microbial glycopolymers, which are activating host innate immunity, should be considered as a new S. aureus vaccine adjuvant. Here, our review aims at highlighting how the latest advances in carbohydrates immunobiology can guide the design and development of better S. aureus vaccines and adjuvants.

Kounis syndrome is an acute myocardial infarction caused by severe allergic reactions or anaphylaxis following vaccination and other triggers, with the associated release of chemical mediators from mast cells causing coronary artery vasospasm. However, treatment with adrenaline is controversial as it paradoxically aggravates cardiac ischemia. Among the many a₁-adrenergic receptor blockers, calcium channel blockers, endogenous vasodilators, and antioxidants that can ameliorate coronary artery vasospasm are some (e.g., prazosin, verapamil, diltiazem, magnesium and vitamin C) that can also stabilize mast cells. Given their dual pharmacological efficacies, these substances may be valuable treatments for Kounis syndrome following coronavirus disease 2019 and other vaccinations.

Purpose: The objective of this study was to determine the prevalence of colonization, serotype distribution, and antimicrobial susceptibility profile of Streptococcus pneumoniae (Pneumococcus) isolated from human immunodeficiency virus (HIV)-infected children before and after single-dose of 13-valent pneumococcal conjugate vaccine (PCV13) vaccination.

Materials and methods: We conducted a prospective cohort study among HIV-infected children above six years of age in Jakarta, Indonesia. Nasopharyngeal swabs were collected from 50 children before vaccination, 12 months, and 18 months after PCV13 vaccination. The swabs were evaluated by bacterial culture, and serotyping were performed using sequential multiplex polymerase chain reactions and Quellung reactions. Antimicrobial susceptibility profiles were determined using the disk diffusion method.

Results: We found Streptococcus pneumoniae colonized 46% (23/50) of total children enrolled before vaccination, which decreased to 19% (n=9/47) at 12 months post-vaccination and 29% (14/48) at 18 months post-vaccination. There was no significant difference in the prevalence of pneumococcal colonization between vaccinated and unvaccinated HIV-infected children (p>0.05). There was a significant decrease in pneumococcal colonization between the baseline, 12 months, and 18 months after vaccination among vaccinated children (p<0.05). Vaccine-type (VT) serotypes (6B, 23F, and 19A) were more prevalent than non-vaccine serotypes before vaccination. Non-vaccine type (NVT) serotypes (6C, 15C) were more prevalent at 12 months post-vaccination. VT serotypes were found at 18 months post-vaccination in vaccinated children. There was a high prevalence of antimicrobial resistance to S. pneumoniae isolates to oxacillin, tetracycline, and sulfamethoxazole-trimethoprim before and after vaccination.

Conclusion: There was a decrease in pneumococcal carriage after PCV vaccination in HIV-infected children, accompanied by changes in serotype distribution from VT serotypes to NVT serotypes.

Introduction: Vitamin D and zinc sufficiency are theoretically acclaimed to influence immune-boosting potentials following various immunizations. Herein, we explored the impact of these micronutrients on immune responses following Oxford-AstraZeneca coronavirus disease 2019 (COVID-19) vaccination among Nigerians.

Methods: Two hundred healthcare workers (HCs) who presented at the Rivers State University Teaching Hospital were recruited during the first dose and followed up 4 weeks post-first and post-second doses. Data (serum vitamin D/zinc, COVID-19 anti-spike immunoglobulin G [ASIgG]) were determined on the day of the first dose and repeated 4 weeks post-first dose and 4 weeks post-second dose. Vitamin D (VitD) status, assessed using serum 25(OH)D, was categorized as sufficient (≥50 nmol/L) or insufficient/deficient (<50 nmol/L) while zinc status was categorized as sufficient (≥11.3 µmol/L) or insufficient (<11.3 µmol/L). Post-second dose ASIgG titer status was categorized as optimal (>7,352 AU/mL) or sub-optimal (<7,352 AU/mL) as defined by the World Health Organization. Statistical significance was defined as p<0.05.

Results: HCs with both VitD and zinc sufficiency (n=97) had higher ASIgG titer levels (4 weeks post-first dose=15,977±367.88 AU/mL; 4 weeks post-second dose=22,603±451.18 AU/mL) after the first and second doses compared to only the VitD sufficient (n=58) cohorts (4 weeks post-first dose=4,680±154.77 AU/mL; 4 weeks post-second dose=7,850±200.60 AU/mL) and the zinc-sufficient (n=63) cohorts (4 weeks post-first dose=5,770±160.41 AU/mL; 4 weeks post-second dose=8,100±206.91 AU/mL) (p<0.05). The VitD and zinc-sufficient HCs were also more likely to achieve optimal ASIgG titer levels (odds ratio, 2.97; 95% confidence interval, 2.11-4.123; p<0.001) 4 weeks post-second dose following adjustment for confounders.

Conclusion: VitD and zinc sufficiency had a positive impact on immune responses following AstraZeneca COVID-19 vaccination.

Purpose: India began its vaccination roll out for coronavirus disease 2019 (COVID-19) on 16th January, 2021 with the healthcare personnel (HCP) being the priority group to receive the vaccine. Dentists constitute a high-risk subgroup to COVID-19 infection. This study was conducted, to assess the knowledge, attitude and perceptions regarding the COVID-19 vaccination amongst the dentists in India.

Materials and methods: A prospective qualitative study was done in Faculty of Dentistry, Jamia Millia Islamia, New Delhi. A self-administered, validated questionnaire was shared with 1,000 dentists. Data was analysed for determining statistical significance of qualitative variables.

Results: About 67.1% were graduates, with Bachelor of Dental Surgery (BDS) degree and 32.9% were postgraduates, with Master of Dental Surgery (MDS) degree; 75.5% were systemically healthy with no reported co-morbidities. About 996 (99.6%) were vaccinated and only 4 subjects were unvaccinated (0.4%). About 70.6% had no hesitancy about getting vaccinated while about 29.4% were hesitant for the same. The main reasons behind vaccine hesitancy were medical or psychological reasons, presence of allergies, comorbidities, lack of unavailability of long-term safety and efficacy data, reports of adverse reactions after vaccination, rapid generation of vaccines, and reports of developing adverse reactions or unexplained deaths after COVID-19 vaccination.

Conclusion: This study has helped to gain an insight into the vaccination status of dentists across India and address the reasons for vaccine hesitancy amongst dentists working in various dental colleges, dental clinics and find ways to address the gaps in the vaccination programme.

This narrative review analyzed roles of several prophylactic vaccinations in adult patients with diabetes, focusing on their safety profiles and clinical effectiveness. Individuals with diabetes mellitus are at increased risk for infections, making vaccination a critical component of their healthcare. The review assessed various vaccines that are particularly relevant for this population, i.e., vaccines for pneumococcus, meningococcus, severe acute respiratory syndrome coronavirus 2, influenza, herpes zoster, human papillomavirus, and dengue. It highlighted the safety profiles and clinical effectiveness of these vaccines in preventing serious infections and improving long-term health outcomes in diabetic patients. Taken together, this review emphasized the importance of prophylactic vaccinations in reducing infection-related morbidity and mortality as well as encouraged fostering greater adoption and advocacy for immunization programs among diabetic adults.

Purpose: Rabies is a deadly zoonotic disease affecting many mammals, including humans. Oral rabies bait vaccines induce an immune response without direct inoculation, and are crucial for controlling rabies in wildlife. This study evaluated the safety and immunogenicity of a new rabies bait vaccine containing a recombinant rabies virus expressing green fluorescent protein (ERAGS-GFP) in wild raccoon dogs.

Materials and methods: To confirm the safety of the ERAGS-GFP vaccine, reversion to virulence was evaluated in 1-day-old suckling mice. The uptake, minimum effective dose, and immunogenicity of the bait vaccine were assessed in raccoon dogs, as was the persistence of post-vaccine immunity. Serum rabies virus neutralizing antibody (VNA) titers were measured using fluorescent antibody virus neutralization.

Results: No adverse effects were noted in mice, guinea pigs, dogs, or raccoon dogs administered the ERAGS-GFP vaccine orally during the test period. The glycoprotein gene of the ERAGS-GFP strain remained unchanged after five reverse passages in 1-day-old mice. Uptake of the bait vaccine was 75.8% in raccoon dogs. The minimum effective dose was at least 10^5.0 TCID₅₀/mL. Forty-three raccoon dogs administered the ERAGS-GFP bait vaccine developed an average VNA titer of 4.23 IU/mL 28 days post-administration. Protective antibody levels were maintained for 4 months.

Conclusion: The ERAGS-GFP bait vaccine showed high uptake and strong immunogenicity in raccoon dogs, and protective antibody levels were maintained for at least 4 months. These results indicate the vaccine's potential for effective rabies control in wildlife, which can reduce the risk of transmission to humans and domestic animals.

Purpose: Effective treatment for animal bites is essential, encompassing immediate measures and protocols for rabies and tetanus vaccination. In this study, we evaluated the effectiveness of the administration of individual and combined rabies-tetanus (RT) vaccines in mice as model animals.

Materials and methods: Animal groups were injected with either undiluted Toxovac^® combined with Rabies vaccine^® (RT/Group 1)/Speeda^® (ST/Group 3), 2-fold diluted Toxovac^® with Rabies vaccine^® (RT1/2/Group 2), or purified tetanus toxoid with Speeda^® (Spurf/Group 4). Mice were immunized with either 2 intraperitoneal (IP) doses at one-week interval or one subcutaneous (SC) dose for rabies immunogenicity, and with one SC dose for tetanus immunogenicity. The potency of the vaccines was determined through challenge test, while their immunogenicity was examined by measuring the anti-rabies and anti-tetanus immunoglobulin G response.

Results: All tested vaccines were potent except Spurf; tetanus was not potent. Rabies' immunogenicity for all combinations through both routes of administration showed comparable antibody response & non-significant difference (p≥0.05) at days 14 and 28 compared to single rabies injected by 2 IP doses. Tetanus' immunogenicity in combinations was compared with Toxovac^®. RT depicted higher antibody response on both days 14 and 28. Whereas RT1/2 showed a non-significant difference on both days 14 and 28. Therefore, rabies has a synergistic effect on tetanus in combination.

Conclusion: The immune response to rabies in combination vaccine injected as a single SC dose was as effective as 2 IP doses of single vaccine. Our results highlight the potential of RT combination vaccine via SC as a cost-effective means to provide protective immunity.

Purpose: Coronavirus disease 2019 (COVID-19) vaccination reduced morbimortality rates due to severe acute respiratory syndrome coronavirus 2 infection worldwide. However, various complications have been reported, including hematologic disorders.

Materials and methods: We conducted a systematic review to synthesize and analyze the current available evidence on the development of hematological disorders associated with COVID-19 vaccination.

Results: A total of 227 patients were reported in the papers that were selected to be included. There was a slight predominance of females (n=114, 50.22%) compared to males (n=113, 49.78%), and the calculated mean age was 54.86±18.94 years. The most frequently reported hematological disorders were Immune thrombocytopenic purpura (n=58, 25.55%), followed by thrombotic thrombocytopenic purpura (n=38, 16.74%). The less frequently recorded cases were acquired factor XIII/13 deficiency (n=2, 0.88%) and pernicious anemia (n=2, 0.88%). Messenger RNA (mRNA)-based COVID-19 vaccines, including Pfizer BioNTech 162b2 (n=106, 46.70%), Moderna mRNA 127-3 (n = 42, 18.50%), and the Bivalent vaccine (n = 1, 0.44%), were the most prevalent (n=150, 66.08%). Most cases developed after the first dose (n=120, 52.86%). In most cases, patient outcomes were favorable (n=175, 77.09%), but there were significant mortality cases (n=23, 10.13%).

Conclusion: Our findings suggest close monitoring of patients who receive the first dose with mRNA technology vaccines, regardless of sex, especially in adults, as they appear more vulnerable to developing hematologic disorders.

Trial registration: PROSPERO Identifier: CRD42023452589.

The recently circulating human metapneumovirus (HMPV) is a serious respiratory infection that affects immunocompromised persons, the elderly, and children. HMPV infections can cause significant morbidity, including pneumonia, bronchiolitis, and worsen chronic respiratory diseases. Despite the clinical burden, there is still no licensed HMPV vaccine. This short review examines the mechanisms underpinning next generation HMPV vaccines, the gene involved, the significant epitopes, the immunological responses they elicit, and the potential impact on herd immunity.