Optimization of the Process for Preparing Bivalent Polysaccharide Conjugates to Develop Multivalent Conjugate Vaccines against Streptococcus pneumoniae or Neisseria meningitidis and Comparison with the Corresponding Licensed Vaccines in Animal Models

Objective:This study aimed to describe,optimize and evaluate a method for preparing multivalent conjugate vaccines by simultaneous conjugation of two different bacterial capsular polysaccharides(CPs)with tetanus toxoid(TT)as bivalent conjugates.Methods:Different molecular weights(MWs)of polysaccharides,activating agents and capsular polysaccharide/protein(CP/Pro)ratio that may influence conjugation and immunogenicity were investigated and optimized to prepare the bivalent conjugate bulk.Using the described method and optimized parameters,a 20-valent pneumococcal conjugate vaccine and a bivalent meningococcal vaccine were developed and their effectiveness was compared to that of corresponding licensed vaccines in rabbit or mouse models.Results:The immunogenicity test revealed that polysaccharides with lower MWs were better for Pn1-TT-Pn3 and MenA-TT-MenC,while higher MWs were superior for Pn4-TT-Pn14,Pn6A-TT-Pn6B,Pn7F-TT-Pn23F and Pn8-TT-Pn11A.For activating polysaccharides,1-cyano-4-dimethylaminopyridinium tetrafluoroborate(CDAP)was superior to cyanogen bromide(CNBr),but for Pn1,Pn3 and MenC,N-(3-dimethylaminopropyl)-N’-ethylcarbodiimide hydrochloride(EDAC)was the most suitable option.For Pn6A-TT-Pn6B and Pn8-TT-Pn11A,rabbits immunized with bivalent conjugates with lower CP/Pro ratios showed significantly stronger CP-specific antibody responses,while for Pn4-TT-Pn14,higher CP/Pro ratio was better.Instead of interfering with the respective immunological activity,our bivalent conjugates usually induced higher IgG titers than their monovalent counterparts.Conclusion:The result indicated that the described conjugation technique was feasible and efficacious to prepare glycoconjugate vaccines,laying a solid foundation for developing extended-valent multivalent or combined conjugate vaccines without potentially decreased immune function.

5-year vaccine protection following a single dose of Vi-tetanus toxoid conjugate vaccine in Bangladeshi children(TyVOID):a cluster randomised trial

Background:WHO currently recommends a single dose of typhoid conjugate vaccine(TCV)in high-burden countries based on 2-year vaccine efficacy data from large randomised controlled trials.Given the decay of immunogenicity,the protection beyond 2 years is unknown.We therefore extended the follow-up of the TyVAC trial in Bangladesh to assess waning of vaccine protection to 5 years after vaccination.

Safety Observation Study on Haemophilus Influenza Type B Conjugate Vaccines Injected at Different Sites in Chinese Infants

In the present study, the safety of Hoemophilus influenza type b conjugate vaccines inoculated in the upper arm deltoid and vastus lateralis muscle was evaluated. 680 infants aged 2-5 months and 6-12 months were selected to be the research subjects in whom the Hib conjugate vaccines were inoculated by injection in the upper arm deltoid and vastus lateralis muscle, respectively. The safety analysis indicated that there were no statistic differences in the incidence rates of adverse reactions when the Hib conjugate vaccines were inoculated at different sites. So we concluded that the safety of inoculation injection of Hib conjugate vaccines in vastus lateralis muscle was the same as that inoculated in the upper arm deltoid.

Impact of the Pneumococcal Heptavalent Conjugated Vaccine on <i>Streptococcus pneumoniae</i>Nasopharyngeal Carriage and Antimicrobial Susceptibility in Children 2-5-Year-Old in Beijing, China

Streptococcus pneumoniae is a primary cause of illness and death among children younger than 5 years in China. The heptavalent pneumococcal conjugate vaccine (PCV7) was the only conjugated vaccine (PCV) available in China from 2008 to 2013. This randomized, controlled, open-label study conducted at 46 Beijing clinics involved 3281 healthy 2-5-year-old Chinese children, randomized 1:1 to receive one dose of the S. pneumoniae heptavalent conjugated vaccine (PCV7) (n = 1643) or Haemophilus influenzae type b conjugate vaccine (Hib) (n = 1638). The main objective of this study was to investigate the impact of PCV7 against that of Hib vaccination in the nasopharyngeal S. pneumoniae colonization in healthy Chinese children. Nasopharyngeal (NP) samples for culture, serotyping and antimicrobial susceptibility testing were collected before vaccination and at Day 60 and 180 post-vaccination. A total 3281 children were enrolled in the study. Demographic characteristics were similar among both study groups: 1641 children received PCV7. Before immunization, S. pneumoniae was isolated in 338 and 360 children in the PCV7 (144 PCV7 isolates) and Hib groups (145 PCV7 isolates), respectively. At Day 180, PCV7 vaccination was more effective than Hib vaccination in reduction NP carriage (20.2% [P = 0.052]) and new acquisition (19.0% [P = 0.066]). When reductions in NP carriage and new acquisition of PCV7 VT plus 6A was analyzed, reduction in the PCV7 vaccinated group achieved statistical significance (P = 0.034 and P = 0.042 versus Hib, respectively). NP carriage of NVT increased in both groups (P = 0.305 between study groups at Day 180). PCV7 decreased NP carriage of non-susceptible VT to amoxicillin (P = 0.000), ceftriaxone (P = 0.047) and MDR (P = 0.024) versus Hib. PCV7 vaccination in Chinese children 2 to 5 years of age was more effective than vaccination with Hib in the reduction of S. pneumoniae nasopharyngeal carriage, new acquisition and non-susceptible isolates.

A new approach for development of vaccine against visceral leishmaniasis: Lipophosphoglycan and polyacrylic acid conjugates

Objective: To determine the antileishmanial vaccine effectiveness of lipophosphoglycan(LPG) and polyacrylic acids(PAA) conjugates on in vivo mice models.Methods: LPG molecule was isolated and purified from large-scale Leishmania donovani parasite culture. Protection efficacies of LPG alone, in combination with Freund's adjuvant, in a physical mixture and in conjugate(consisting of various LPG concentrations) with PAA, were comparatively determined by various techniques, such as cultivation with the micro-culture method, assessment of in vitro infection rates of peritoneal macrophages, determination of parasite load in liver with Leishman-Donovan Units, and detection of cytokine responses.Results: Obtained results demonstrated that the highest vaccine-mediated immune protection was provided by LPG-PAA conjugate due to all parameters investigated. According to the Leishman-Donovan Units results, the sharpest decline in parasite load was seen with a ratio of 81.17% when 35 mg LPG containing conjugate was applied. This value was 44.93% for the control group immunized only with LPG. Moreover, decreases in parasite load were 53.37%, 55.2% and 65.8% for the groups immunized with 10 mg LPG containing LPG-PAA conjugate, a physical mixture of the LPG–PAA, and a mixture of LPG + Freund's adjuvant, respectively. Furthermore, cytokine results supported that Th1 mediated protection occurred when mice were immunized with LPG-PAA conjugate.Conclusions: It has been demonstrated in this study that conjugate of LPG and PAA has an antileishmanial vaccine effect against visceral leishmaniasis. In this respect, the present study may lead to new vaccine approaches based on high immunogenic LPG molecule and adjuvant polymers in fighting against Leishmania infection.

Persistence of Pleural Effusions and Empyemas after Pneumococcal Conjugate Vaccine Implementation in Uruguay

In Uruguay a post pneumococcal conjugate vaccine implementation surveillance of hospitalized children with pneumonia showed an increase of complicated pneumonias, while uncomplicated pneumonias decreased. Out of 151 pleural effusions, 62 were empyemas requiring drainage, the rest of cases were treated with antibiotics with a favorable outcome. Patient’s vaccinated status varied. Pneumococcal etiology was poorly documented. The few identified sero-types were 1 and 3, a fact that urges PCV13 use for their control.

Safety of a 13-Valent Pneumococcal Conjugate Vaccine in Elderly Adults Previously Immunized with a 23-Valent Pneumococcal Polysaccharide Vaccine: An Open-Label Trial

An open-label, multicenter study was conducted to describe the safety of the 13-valent pneumococcal conjugate vaccine (PCV13) in 1049 individuals aged ≥68 years, who had previously been immunized with the unconjugated 23-valent pneumococcal polysaccharide vaccine (PPSV23). In addition, the safety profile of PCV13 in this study was compared, in a post-hoc descriptive analysis, to that observed in other elderly populations, who had received PCV13 or PPSV23 as part of other completed studies. Local (56.6%) and systemic reactions (58.4%) were very common, but were mainly mild, and of short duration (mean: 1.3 - 4.6 days). There were no related serious adverse events (AEs) within 1 month after PCV13. 123 days after PCV13 and 94 days after a nonstudy influenza vaccine, a case of transient Guillain-Barré syndrome occurred, which the investigator assessed as possibly related to the vaccination. Reactogenicity observed in this study population was generally similar to that of other elderly study populations with PPSV23-preimmunized adults, and with PPSV23-naive adults. Reactogenicity was less common in this study than that observed in PPSV23-preimmunized adults who were revaccinated with PPSV23 rather than a subsequent dose of PCV13. There were no related serious AEs reported after PCV13 and PPSV23 in these comparator studies. Conclusion: PCV13 may be administered safely to older adults previously immunized with PPSV23. (ClinicalTrials. gov Identifier: NCT00500266)

Potential carrier priming effect in Australian infants after 7-valent pneumococcal conjugate vaccine introduction

AIM:To investigate evidence of clinical protection in infants after one dose of 7-valent pneumococcal conjugate vaccine(7vPCV) owing to carrier priming.METHODS:Using Australian National Notifiable Diseases Surveillance System data,we conducted a descriptive analysis of cases of vaccine type invasive pneumococcal disease(VT-IPD) during "catch-up" years,when 7vPCV was carrier primed by prior administration of DTPa vaccine.We compared the number of VT-IPD cases occurring 2-9 wk after a single dose of 7vPCV(carrier primed),with those < 2 wk post vaccination,when no protection from 7vPCV was expected yet.Further comparison was conducted to compare the occurrence of VT-IPD cases vs non-VT-IPD cases after a single carrier-primed dose of 7vPCV.RESULTS:We found four VT-IPD cases occurring <2 wk after one carrier primed dose of 7vPCV while only one case occurred 2-9 wk later.Upon further comparison with the non-VT-IPD cases that occurred after one carrier primed dose of 7vPCV,two cases were detected within 2 wk,whereas seven occurred within2-9 wk later;suggesting a substantial level of protection from VT-IPD occurring from 2 wk after carrier-primed dose of 7vPCV.CONCLUSION:This data suggest that infants may benefit from just one dose of 7vPCV,likely through enhanced immunity from carrier priming effect.If this is proven,an adjusted 2-dose schedule(where the first dose of PCV is not given until after DTPa) may be sufficient and more cost-effective.

<i>Streptococcus pneumoniae</i>Upper Respiratory Carriage in Costa Rican Children with Otitis Media before the Introduction of the Heptavalent Conjugated Vaccine in the National Immunization Program

Objective: The aim of this study was to analyze the NP/OP S. pneumoniae serotype distribution and potential vaccine coverage in Costa Rican children with Otitis Media (OM) before the introduction of PCV-7 in the National Immunization Program (NIP). Methods: Between 2002 and 2006, NP and OP samples were obtained from 641 children from 6 to 79 months of age, at the time of OM diagnosis. S. pneumoniae serotyping and antimicrobial susceptibility were performed. Results: 386 S. pneumoniae isolates were recovered. The most common S. pneumoniae serotypes (ST) were: ST 6B, ST 14, ST 19F. Penicillin non-susceptibility was observed among 57% of the isolates obtained from children < 24 months of age. 15% strains were multidrug resistant. Potential vaccine coverage was: PCV-7: 60%;PCV-10: 62%;and PCV-13: 76% and against penicillin non-susceptible and multidrug resistant isolates was: PCV-7;59% and 83%, respectively;PCV-10: 60% and 85%, respectively and PCV-13: 74% and 96%, respectively. Conclusions: S. pneumoniae was isolated from the NP and/or OP in the majority (59%) of studied children with OM. At a statistical significant level, only serotype 3 was more frequently isolated among children >24 months of age. Antibiotic non-susceptibility and MDR were significantly higher in children <24 months of age. This study demonstrates that PCV-13 offers the highest potential vaccine coverage and serves to assess the impact of introduction of one of the conjugated vaccines in the NIP in Costa Rica.

Impact of Seven Valent Pneumococcal Conjugate Vaccine on Nasopharyngeal Carriage in Young Children in Okinawa, Japan

In Japan, the heptavalent pneumococcal conjugate vaccine (PCV7) became available in February 2010 and was subsidized by the national funding system from May 2011 in Okinawa, after which it was incorporated into the national immunization practice (NIP) in April 2013 using a 3 + 1 schedule for all infants. We conducted an annual survey in 2012 to determine the effect of PCV7 on nasopharyngeal colonization by pneumococcal serotypes and to analyze the risk factors for colonization in infants. Nasopharyngeal swabs for pneumococcal isolation and serotyping were obtained from infant 2 to 22 months of age before and after PCV7 immunization among 4 clinics in Okinawa, Japan. Between January 2012 and December 2012, nasopharyngeal swabs for bacterial cultures were obtained among 782 infants aged 2 to 22 months old and demographic data was obtained among 725 participant infants. Among the 725 evaluable infants, 193 pneumococcal strains were detected in 180 infants for an overall nasopharyngeal carriage of 24.8%. The main capsular serotypes isolated were 6C (16.1%), 19A (12.4%) and 15B (9.8%). Carriage of PCV7 serotypes accounted for 21.8% (42/193). The result of multivariate data analysis showed the pneumococcal carriage rate of non-PCV7 serotypes was significantly (P < 0.001) high in infant with siblings and daycare attendance. On the other hand, the result of multivariate data analysis showed that carriage rate of PCV7 serotype had only significantly high risk in infant with siblings and did not have a significant risk dependent on age and daycare attendance. Carriage PCV7 serotypes increased in the presence of other siblings, while PCV7 vaccination was shown to eliminate daycare attendance as a risk. The results of this study demonstrates that PCV7 vaccination decrease the overall nasopharyngeal carriage of PCV7 serotypes in vaccinated children including children at risk such as children attending day-care centers.

Effect of 7 and 13-Valent Pneumococcal Conjugate Vaccines Different Number of Doses for Pneumonia Control in 2008 and 2010 Birth Cohort Children

The 7-valent pneumococcal conjugate vaccine (PCV) was introduced in Uruguay in March 2008. In April 2010, it was replaced by PCV13. Surveillance of both vaccines was performed on hospitalized children with consolidated pneumonia. The effect of different number of vaccine doses was evaluated in 2008 and 2010 birth cohorts vaccinated with PCV7 and PCV13 respectively. The study aims to estimate the effects of PCV7 and PCV13 different number of doses on consolidated pneumonia, through the study of hospitalized children from 2008 and 2010 birth cohorts. Vaccination records of every child were available providing precise vaccination data;therefore a new approach was used to estimate PCVs effect. Incidence rate was calculated for each year of the study and for the different number of vaccine doses used each year. Exposure was calculated as person per year and rate ratio values determined the decrease of consolidated pneumonias. This decrease in percentage was estimated as the difference between the incidence with no vaccine and the incidence of every one of the doses. Incidence rate ratio revealed significant values for the three vaccine doses of PCVs for both cohorts. Upon comparing incidences, significant reduction percentages of consolidated pneumonia admissions were found. The reduction percentage of consolidated pneumonia for fully vaccinated (3 doses) patients was 69.3% and 84.6 % for PCV7 and PCV13, respectively. These results confirm that PCV7 and PCV13 are highly effective for reducing pediatric hospitalizations due to consolidated pneumonia, as reported by other national publications and demonstrated by international researchers.

Synthesis, Characterization, and Immunological Properties of LPS-Based Vaccines Composed of O-Polysaccharides Conjugated with Recombinant Exoprotein A from Pseudomonas aeruginosa

Pseudomonas aeruginosa remains one of the major pathogens affecting immunocompromised patients. LPS-based monovalent (MV) and polyvalent (PV) conjugate vaccines were prepared from the most prevalent strains of P. aeruginosa International Antigenic Typing Scheme (IATS) 6, 10, 11 and 20 to evaluate their immunogenicity and protective capacities from infection by the pathogens. Conjugation of the O-polysaccharide (O-PS) antigens of P. aeruginosa strains to the common immunogenic recombinant Exotoxin A (rEPA) supports the multi-antigenic approach for the development of a vaccine that provides cross protection against various strains of the pathogen. The O-PSs were indirectly conjugated through adipic acid dihydrazide (ADH) to rEPA by carbodiimidemediated condensation reaction. Mice were immunized with the conjugates emulsified with monophosphoryl lipid A (MPL) or Freund's adjuvant compared with conjugates without adjuvant, unconjugated mixture of rEPA and O-PS emulsified with MPL, and sterile saline. The MV and PV vaccines emulsified with MPL adjuvant elicited the highest anti-O-PS IgM and IgG antibodies. Immunization of mice with MV vaccines derived from IATS 10, 11, and 20, emulsified with MPL adjuvant provided a high level of protection against the homologous bacterial strain. Similarly, high protection was obtained when mice were immunized using PV and challenged separately with bacterial strains 10, 11, and 20, but lower protection against the IATS 6 strain. Also, high cross protection of MV vaccine derived from O-PS of IATS 10 and 20 was obtained against P. aeruginosa IATS 11 strain. The in vivo protection correlated with the level of anti-O-PS IgG in the mice serum.

Effectiveness of 7-valent pneumococcal conjugate vaccine: A meta-analysis of post-marketing studies

AIM:To investigate the 7-valent pneumococcalconjugate vaccine(PCV7)effectiveness.METHODS:A systematic literature review of studies which evaluated the effectiveness of PCV7 vaccine was performed searching the keyword"heptavalent pneumococcal conjugate vaccine"in PubM ed and Scopus until March 16,2013.The selection of potential eligible articles was done by two researchers independently on the basis of abstract and title and only post-marketing studies were included in the systematic review.Data extraction was carried out by two researchers with respect to invasive pneumococcal diseases due to both all and vaccine serotypes in pre-vaccine and postvaccine periods in children less than 5 years.Results of studies which were considered suitable for meta-analysis were combined by means of relative risk(RR)with95%CI.Vaccine effectiveness was calculated as(1-RR)×100.Heterogeneity was assessed by I2 and a random effects model was used to combine data in the case of heterogeneity.RevM an 5 was used to pool data.RESULTS:On the whole,757 eligible papers were identified from the literature search in PubM ed and Scopus.Of them,62 were finally considered in the systematic review and 38 were included in the meta-analysis.In all post-marketing studies included in the systematic review the incidence of invasive pneumococcal diseases due to vaccine serotypes declined significantly with the exception of few studies showing stability or a slight,but not significant,increase.Furthermore most of studies highlighted also a reduction in the incidence of invasive pneumococcal diseases due to all serotypes.With regards to meta-analysis,a random effects model was used to combine data because of the high heterogeneity.Data combination showed that the effectiveness of PCV7in reducing invasive pneumococcal diseases due to vaccine serotypes and to all serotypes was 84%(95%CI:74%-90%)and 53%(95%CI:46%-59%)respectively.These results are confirmatory with respect to the efficacy of PCV7 against invasive pneumococcal diseasesdue to vaccine serotypes.CONCLUSION:PCV7 implementation determines a significant decrease of invasive pneumococcal diseases.

Penicillin Resistance in Nasopharyngeal Streptococcus pneumoniae among Children with Sickle Cell Disease Immunized with 7-Valent Pneumococcal Conjugate Vaccine

To assess the prevalence, the antimicrobials resistance and to identify risk factors of nasopharyngeal colonization by Streptococcus pneumoniae in children with sickle cell disease (SCD) using prophylactic penicillin and immunized with 7-valent pneumococcal conjugate vaccine. A total of 424 swabs were collected from the nasopharynx in 216 children with SCD and 109 samples from the control group, both from 2 to 60 months age range. Isolation and identification of pneumococci followed standard procedures. Minimum inhibitory concentration (MIC) for penicillin was determined by the E-test method. Prevalence of nasopharyngeal colonization by pneumococci in children with SCD was 17%, and 11% in the control group. The risk factors for increased colonization in children with SCD were the presence of more than five people at home, daycare/school attendance and low prophylaxis compliance. The prevalence of strains with penicillin resistance was 57.5% in patients with SCD and 25% in the control group. Conclusions: Prevalence of pneumococci nasopharyngeal colonization was similar among the study groups. Prophylactic use of penicillin may have increased the prevalence of resistant strains. The vaccine did not decrease the colonization with penicillin resistant strains.

Bioinspired Passive Tactile Sensors Enabled by Reversible Polarization of Conjugated Polymers

Tactile perception plays a vital role for the human body and is also highly desired for smart prosthesis and advanced robots.Compared to active sensing devices,passive piezoelectric and triboelectric tactile sensors consume less power,but lack the capability to resolve static stimuli.Here,we address this issue by utilizing the unique polarization chemistry of conjugated polymers for the first time and propose a new type of bioinspired,passive,and bio-friendly tactile sensors for resolving both static and dynamic stimuli.Specifically,to emulate the polarization process of natural sensory cells,conjugated polymers(including poly(3,4-ethylenedioxythiophen e):poly(styrenesulfonate),polyaniline,or polypyrrole)are controllably polarized into two opposite states to create artificial potential differences.The controllable and reversible polarization process of the conjugated polymers is fully in situ characterized.Then,a micro-structured ionic electrolyte is employed to imitate the natural ion channels and to encode external touch stimulations into the variation in potential difference outputs.Compared with the currently existing tactile sensing devices,the developed tactile sensors feature distinct characteristics including fully organic composition,high sensitivity(up to 773 mV N^(−1)),ultralow power consumption(nW),as well as superior bio-friendliness.As demonstrations,both single point tactile perception(surface texture perception and material property perception)and two-dimensional tactile recognitions(shape or profile perception)with high accuracy are successfully realized using self-defined machine learning algorithms.This tactile sensing concept innovation based on the polarization chemistry of conjugated polymers opens up a new path to create robotic tactile sensors and prosthetic electronic skins.

COVID-19 Vaccine Acceptance and Hesitancy among Pregnant Women: A Knowledge, Attitude, and Perceived Risks Survey in Lusaka, Zambia

Introduction: The coronavirus disease 2019 (COVID-19) is an infectious disease of the respiratory tract caused by SARS-CoV-2. Since its emergence, there have been increased rates of transmission and spread, morbidity and mortality which led to the development of COVID-19 vaccines to address the pandemic. This study assessed acceptance, knowledge, attitude, and perceived risks regarding COVID-19 vaccines among pregnant women attending antenatal care at two First-Level Hospitals in Lusaka, Zambia. Materials and Methods: This was a cross-sectional study that was conducted among 241 pregnant women using a questionnaire from August 2023 to October 2023 in two First-Level Hospitals in Lusaka district, Zambia. The collected data were analyzed using IBM Statistical Package for Social Sciences (SPSS) version 22.0. Statistical analysis was performed using a Chi-square test. The statistical significance was set at a 95% confidence level. Results: Of the 241 participants, 107 (42.7%) were aged between 24 and 34 years. Overall, 64.3% accepted the COVID-19 vaccines, of which 122 (50.6%) were already vaccinated. Further, 203 (84.6%) of the pregnant women had good knowledge, and 199 (82.6%) had positive attitudes towards COVID-19 vaccines. However, 58.5% thought COVID-19 vaccines were not safe and could cause infertility. Alongside this, 70.1% thought that COVID-19 vaccines were harmful during pregnancy. Having good knowledge of COVID-19 vaccines was associated with age (p = 0.049), education status (p = 0.001), and employment status (p = 0.001). Having a positive attitude towards COVID-19 vaccines was associated with education status (p = 0.001) and employment status (p = 0.001). Conclusion: This study found that most pregnant women had good knowledge, and positive attitudes, and the majority accepted the COVID-19 vaccine. Encouragingly, most of the pregnant women who accepted the COVID-19 vaccines were already vaccinated. Most pregnant women thought that COVID-19 vaccines had side effects, were not safe, and could be harmful during pregnancy. Consequently, this could have contributed to the hesitancy to receive a vaccine among some participants. The findings of this study demonstrate the need to provide pregnant women with continuous educational programs on the benefits of vaccinations for themselves and their children.

Adverse Side Effects of COVID-19 Vaccines in Older Adults: A Comprehensive Review of Current Research

The purpose of this research review was to examine current scientific literature on COVID-19 vaccine-induced side effects in older adults. We reviewed studies focusing on side effects categorized into cardiologic, immunologic, neurologic, and ocular groups. Cardiologic side effects included myocarditis, pericarditis, and myocardial infarction. Immunologic conditions examined were anaphylaxis and vaccine-induced immune thrombotic thrombocytopenia. Neurologic side effects included Guillain-Barré syndrome and Bell’s Palsy. Ocular side effects covered ocular swelling, submacular hemorrhage, and corneal graft rejection after keratoplasty and Descemet membrane endothelial keratoplasty. Additionally, less common side effects in older adults were reviewed but found to be statistically rare. Overall, COVID-19 vaccine-induced side effects in elderly populations were rare. We concluded that the vaccine’s efficacy in preventing excess deaths due to COVID-19 is significant, and the risk of these rare side effects does not justify foregoing vaccination in at-risk individuals. Patients at higher risk for these side effects should be informed, and additional considerations should be made by their treating physician. This review aims to increase awareness of rare vaccine-induced side effects to encourage further studies, enhancing understanding of their etiology and prevalence in at-risk older adult populations.

Recent advances on vaccines against malaria: A review

This review aims to summarize the currently viable vaccine strategies including the approved vaccines and the those in trials for next-generation malaria vaccines.Data on malaria vaccine development was collected through a comprehensive review.The literature search was performed using databases including Google Scholar,PubMed,NIH,and Web of Science.Various novel approaches of vaccination are being developed,including those based on radiation-attenuated strategies,monoclonal antibodies,targeted immunogenic peptides,RNA and DNA vaccines,nanoparticle-based vaccines,protein-based vaccination protocols,and whole organism-based vaccination strategies.Trials on RTS,S have entered phase Ⅲtesting,and those based on blood-stage vaccines and vaccines to interrupt malarial transmission have advanced to higher stages of trials.Mathematical modeling,combined drug and vaccine strategies,mass drug administration,polyvalent vaccine formulations,and targeted vaccination campaigns is playing an important role in malarial prevention.Furthermore,assessing coverage,accessibility,acceptability,deployment,compilation,and adherence to specific vaccination strategies in endemic regions is essential for vaccination drives against malaria.

Dengue outbreaks in northern Nigeria: Evaluating the recommended Takeda vaccine and future prevention strategies

Dengue fever,caused by the dengue virus(DENV),poses a significant public health challenge globally,with Nigeria experiencing sporadic outbreaks.A clear understanding of the dengue burden has not been achieved in Nigeria,just as in other African countries.Understanding the epidemiology and burden of dengue fever is essential for effective prevention and control strategies.This paper examines the recent dengue outbreaks in northern Nigeria,particularly in Sokoto state,and evaluates the recommended Takeda dengue vaccine(TDV)along with future prevention strategies.Despite limited surveillance and underreporting,dengue fever is endemic in Nigeria(with over 5 million cases and 5000 dengue-related deaths in 2023),with recent outbreaks indicating a growing concern.The TDV,a live attenuated tetravalent vaccine,has shown promise in preventing dengue fever,but challenges such as vaccine acceptance and access-ibility need to be addressed.Global urbanization contributes to the disease's spread,which is influenced by factors such as population density,cultural beliefs,water storage practices,hygiene,and water supply accessibility.Future prevention strategies must focus on government intervention,community practices,and innovative vector control measures to mitigate the spread of DENV in Nigeria.This study will serve as a valuable reference for policy-makers,researchers,and clinicians in the management and control of DENV in Nigeria and Africa as a whole.

Plant-based vaccines against viral hepatitis: A panoptic review

The traditional vaccines against hepatitis have been instrumental in reducing the incidence of some types of viral hepatitis;however,the need for cost-effective,easily distributable,and needle-free vaccine alternatives has led to the exploration of plant-based vaccines.Plant-based techniques offer a promising avenue for producing viral hepatitis vaccines due to their low-cost cultivation,scalability,and the potential for oral administration.This review highlights the successful expression of hepatitis B surface antigens in plants and the subsequent formation of virus-like particles,which have shown immunogenicity in preclinical and clinical trials.The challenges such as achieving sufficient antigen expression levels,ensuring consistent dosing,and navigating regulatory frameworks,are addressed.The review considers the potential of plant-based vaccines to meet the demands of rapid vaccine deployment in response to outbreaks and their role in global immunization strategies,particularly in resource-limited settings.This review underscores the significant strides made in plant molecular farming and the potential of plant-based vaccines to complement existing immunization methods against viral hepatitis.