Development, Optimization and Evaluation of Mucoadhesive Microspheres of Amoxicillin for the Treatment of H.Pylori by Full Factorial Design.

OBJECTIVE: This work is aimed to formulate and evaluate Mucoadhesive Microspheres contain Amoxicillin for the effective use in the treatment of H.Pylori. METHODS: Microspheres were prepared using Emulsification-cross linking technique. To this guar gum (GG) and sodium alginate (SA) was dissolved in 200 ml of water and allowed to swell for 24 h at room temperature. And separately chitosan (CH) was dissolved in 2% (v/v) glacial acetic acid and this also kept for 24 h to swell or dissolve properly. After 24 h this swelled mixture was mixed under magnetic stirrer (Remi, India) at specific stirring rate for 1 h in order to find homogeneous mass of both the gum. Then slurry of chitosan also was homogenized for half an hour. The drug, Amoxicillin (1g) was then added to the chitosan solution and mixed homogeneously. RESULTS: The aim of the study was to formulate and evaluate microspheres, for SR of the chosen drug. The particle size of microspheres was in the range of 200-500 µ, maximum mucoadhesive property observed was 57.41% for Optimized formulation F-9, Drug release 68.52% till 8 h, and the maximum entrapment was 94.87% for F-9 formulation. The work also aims to study various parameters affecting the behavior of microspheres in oral dosage form. CONCLUSION: Drugs with short half life that are absorbed from the gastrointestinal tract (GIT) are eliminated rapidly from the blood flow. To avoid this, the oral SR was developed as this formulation released the drug slowly into the GIT and maintained a stable drug concentration in the serum for a longer duration of time.

Arenavirus-Based Vectors Generate Robust SIV Immunity in Non-Human Primates.

Arenavirus-based vectors are being investigated as therapeutic vaccine candidates with the potential to elicit robust CD8 T-cell responses. We compared the immunogenicity of replicating (artPICV and artLCMV) and non-replicating (rPICV and rLCMV) arenavirus-based vectors expressing simian immunodeficiency virus (SIV) Gag and Envelope (Env) immunogens in treatment-naïve non-human primates. Heterologous regimens with non-replicating and replicating vectors elicited more robust SIV IFN-γ responses than a homologous regimen, and replicating vectors elicited significantly higher cellular immunogenicity than non-replicating vectors. The heterologous regimen elicited high anti-Env antibody titers when administered intravenously, with replicating vectors inducing significantly higher titers than non-replicating vectors. Intramuscular immunization resulted in more durable antibody responses than intravenous immunization for both vector platforms, with no difference between the replicating and non-replicating vectors. Overall, both replicating and non-replicating arenavirus vectors generated robust T- and B-cell-mediated immunity to SIV antigens in treatment-naïve non-human primates, supporting further evaluation of these vectors in a clinical setting for HIV therapy.

Antimicrobial resistance in food-borne pathogens at the human-animal interface: Results from a large surveillance study in India.

Background: The burden of foodborne diseases and antimicrobial resistance carried by key foodborne pathogens in India is unknown due to a lack of an integrated surveillance system at the human-animal interface. Methods: We present data from the WHO-AGISAR (Advisory Group on Integrated Surveillance of Antimicrobial Resistance), India project. Concurrent human and animal sampling was done across a large area across north India. Community-acquired diarrhea cases (n = 1968) of all age groups were included. Cross-sectional sampling of stool/ intestinal contents (n = 487) and meat samples (n = 419) from food-producing animals was done at farms, retail shops, and slaughterhouses. Pathogens were cultured and identified, and antimicrobial susceptibility was performed. Results: Over 80% of diarrhoeal samples were obtained from moderate to severe diarrhea patients, which yielded EAEC (5%), ETEC (4.84%), EPEC (4.32%), and Campylobacter spp. (2%). A high carriage of EPEC (32.11%) and Campylobacter spp. (24.72%) was noted in food animals, but the prevalence of ETEC (2%) and EAEC (1%) was low. Atypical EPEC (aEPEC, 84.52%, p ≤0.0001) were predominant and caused milder diarrhea. All EPEC from animal/poultry were aEPEC. Overall, a very high level of resistance was observed, and the MDR rate ranged from 29.2% in Campylobacter spp., 53.6% in EPEC, and 59.8% in ETEC. Resistance to piperacillin-tazobactam, cefepime, ceftriaxone, and co-trimoxazole was significantly higher in human strains. In contrast, resistance to ciprofloxacin, aminoglycosides, and tetracycline was higher in animal strains, reflecting the corresponding usage in human and animal sectors. ESBL production was commoner in animal isolates than in humans, indicating high use of third-generation cephalosporins in the animal sector. C. hyointestinalis is an emerging zoonotic pathogen, first time reported from India. Conclusion: In one of the most extensive studies from India, a high burden of key foodborne pathogens with MDR and ESBL phenotypes was found in livestock, poultry, and retail meat.

Flt3 agonist enhances immunogenicity of arenavirus vector-based simian immunodeficiency virus vaccine in macaques.

Arenaviral vaccine vectors encoding simian immunodeficiency virus (SIV) immunogens are capable of inducing efficacious humoral and cellular immune responses in nonhuman primates. Several studies have evaluated the use of immune modulators to further enhance vaccine-induced T-cell responses. The hematopoietic growth factor Flt3L drives the expansion of various bone marrow progenitor populations, and administration of Flt3L was shown to promote expansion of dendritic cell populations in spleen and blood, which are targets of arenaviral vectors. Therefore, we evaluated the potential of Flt3 signaling to enhance the immunogenicity of arenaviral vaccines encoding SIV immunogens (SIVSME543 Gag, Env, and Pol) in rhesus macaques, with a rhesus-specific engineered Flt3L-Fc fusion protein. In healthy animals, administration of Flt3L-Fc led to a 10- to 100-fold increase in type 1 dendritic cells 7 days after dosing, with no antidrug antibody (ADA) generation after repeated dosing. We observed that administration of Flt3L-Fc fusion protein 7 days before arenaviral vaccine increased the frequency and activation of innate immune cells and enhanced T-cell activation with no treatment-related adverse events. Flt3L-Fc administration induced early innate immune activation, leading to a significant enhancement in magnitude, breadth, and polyfunctionality of vaccine-induced T-cell responses. The Flt3L-Fc enhancement in vaccine immunogenicity was comparable to a combination with αCTLA-4 and supports the use of safe and effective variants of Flt3L to augment therapeutic vaccine-induced T-cell responses.IMPORTANCEInduction of a robust human immunodeficiency virus (HIV)-specific CD4+ and CD8+ T-cell response through therapeutic vaccination is considered essential for HIV cure. Arenaviral vaccine vectors encoding simian immunodeficiency virus (SIV) immunogens have demonstrated strong immunogenicity and efficacy in nonhuman primates. Here, we demonstrate that the immunogenicity of arenaviral vectors encoding SIV immunogens can be enhanced by administration of Flt3L-Fc fusion protein 7 days before vaccination. Flt3L-Fc-mediated increase in dendritic cells led to robust improvements in vaccine-induced T- and B-cell responses compared with vaccine alone, and Flt3L-Fc dosing was not associated with any treatment-related adverse events. Importantly, immune modulation by either Flt3L-Fc or αCTLA-4 led to comparable enhancement in vaccine response. These results indicate that the addition of Flt3L-Fc fusion protein before vaccine administration can significantly enhance vaccine immunogenicity. Thus, safe and effective Flt3L variants could be utilized as part of a combination therapy for HIV cure.

Mucoadhesive Microspheres: A Promising Delivery System for Helicobacter Pylori (H. pylori) Treatment.

A major worldwide health problem, Helicobacter Pylori (H. pylori) infection is associated with a number of gastrointestinal disorders, such as gastric cancer and peptic ulcers. The shortcomings of traditional treatment plans often include adverse effects, low patient compliance, and the emergence of antibiotic resistance. Investigating different delivery methods is thus necessary to improve the effectiveness of treatment. Mucoadhesive microspheres show promise as a method for delivering anti H. pylori drugs in a targeted and sustained manner. With their ability to stick to the stomach mucosa, these microspheres increase the local concentration of the medication and guarantee a more thorough removal of the pathogen. The potential of Mucoadhesive microspheres in the management of H. pylori infection is examined in this review. We explore the properties and benefits of Mucoadhesive polymers, the production techniques for microspheres, and the variables affecting their functionality. To provide a thorough grasp of this delivery system, a variety of drug-loading strategies, release mechanisms, and in vitro and in vivo assessment methodologies are covered. The potential of Mucoadhesive microspheres to overcome the drawbacks of traditional therapy is shown by highlighting recent developments in their formulation and their therapeutic consequences. Mucoadhesive microspheres constitute an important advancement in the treatment of Helicobacter pylori because they guarantee a regulated release of antibiotics and improve medication absorption at the site of infection. In order to fully appreciate the advantages of this novel delivery method, further study is necessary. Future research paths and the difficulties in the clinical translation of this technology are also discussed.

Establishing continuum in Transcranial Doppler characteristics of IIH, migraine and healthy controls- An exploratory study.

BACKGROUND: IIH is a severe form of headache that often has superimposed migraine and often it is very difficult to distinguish the two forms of headache. Intracranial hemodynamics is a relatively unexplored means of distinguishing between the two forms of headache. OBJECTIVES: We aimed to study intracranial flow dynamics using Transcranial Doppler in patients with IIH, migraine, and normal controls. MATERIALS AND METHODS: It was a hospital-based observational study that included 51 people with IIH, 87 people with migraine, and 101 healthy controls and all were subjected to TCD study after detailed clinical examination. RESULTS: Mean age of patients in three groups were similar with the mean age in IIH being 33.41 ± 10.75 (age in years ± SD). Vision loss was present in 66.67% of patients with IIH, and most common field defect was generalized constriction (27.5%). Neuroimaging was abnormal in 94.11% of patients of IIH with mean CSF pressure was 31.27±5.32 cm of water. Of all the TCD-measured velocities, mean flow velocity (MFV) showed a significant difference in all three groups with (p-value <0.001). The pulsatility index, both for middle cerebral arteries as well as ophthalmic arteries showed a significant difference in the three groups with the highest values in IIH patients (p-value<.001). The mean VMR in IIH (1.11±0.32) was lower than the mean VMR in migraine (1.34±0.43) as well as controls (1.49±0.46). CONCLUSION: TCD parameters like MFV and PI are useful parameters that show considerable variation and can be used to differentiate between IIH and migraine.

Atypical Presentation Resembling Acute Leukoencephalopathy With Restricted Diffusion in Staphylococcus aureus Meningoencephalitis.

Meningoencephalitis refers to inflammation of the brain and meninges. It can be caused by various organisms, such as Neisseria meningitidis, Streptococcus pneumoniae, and so on. Staphylococcus aureus causing meningoencephalitis is relatively rare. It is mainly encountered in patients who have undergone surgeries in the past. Acute leukoencephalopathy with restricted diffusion (ALERD) is a type of encephalopathy that can involve both white and grey matter of the brain, and it has a characteristic "bright tree appearance" on MRI. It can be because of various infectious etiologies or caused by various toxins. Neurological sequelae are observed in about two out of three cases. Here, we describe a case of S. aureus meningoencephalitis with ALERD, which has been seldom reported. More awareness about this is required among primary care physicians for timely diagnosis and management to prevent any complications.

Otogenic Cerebellar Abscess with Polymicrobial Anaerobic Infection in a Young Female- A Rare Presentation.

Brain abscess is a serious clinical condition caused by a localized collection of pus within the brain tissue. This typically occurs as a result of an infection that originates from a nearby area, such as an ear, sinus, or dental infection, or an infection in the bloodstream. Streptococcus and Staphylococcus species are the most common organisms implicated in brain abscesses. Apart from aerobic growth, cases of mixed infections of both aerobic and anaerobic organisms are also commonly reported in the literature. Herein we report a 23-year-old immunocompetent female with chronic otitis media who presented with cerebellar abscess where the aerobic growth was sterile and anaerobic culture revealed pure growth of dual anaerobes viz… Peptostreptococcus and Bacteroides thetaiotaomicron. This case highlights the importance of prompt diagnosis and management of polymicrobial anaerobic infection in cases of brain abscess.

Cr- and Ga-Modified ZSM-5 Catalyst for the Production of Renewable BTX from Bioethanol.

Light aromatics (benzene, toluene, and xylene, collectively known as BTX) are essential commodity chemicals in the petrochemical industry. The present study examines the aromatization of bioethanol with Cr- and Ga-modified ZSM-5. Both Cr and Ga were incorporated by the ion-exchange method. Cr-modified ZSM-5 outperforms the Ga-modified ZSM-5 and H-ZSM-5 catalysts. Cr-H-ZSM-5 almost doubled the carbon yield of aromatics compared to H-ZSM-5 at an optimum reaction temperature of 450 °C. Cr-H-ZSM-5 produced aromatics with a yield of ~40 %. The effect of dilution in feed on BTX production is also studied. Cr-H-ZSM-5 was found to be more active than H-ZSM-5. Complete ethanol conversion was obtained with both pure and dilute bioethanol. The Bronsted-Lewis acid (BLA) pair formed after metal incorporation is responsible for dehydrogenation followed by aromatization, leading to increased aromatic production.

Unveiling the role of NK cells, NKT-like cells, and γδ cells in pathogenesis of type 1 reactions in leprosy.

Leprosy is a disease with spectral clinical manifestations along with two types of reactions, type 1 reaction (T1R) and type 2 reaction (T2R). T1R especially occurs because of the defensive upgradation of cell-mediated immunity (CMI) to M. leprae antigens. T1R is the main cause of disability in leprosy. The role of conventional adaptive T cells has been well studied to understand T1R. A comprehensive understanding of the role of unconventional T cells in the manifestation of inflammation during T1R is crucial and has not been studied. In our study, we found significantly higher plasma levels of TNFα, IL1ß, IL17, and IP10 in T1R when compared to non-reaction (NR). Gene expression for cytokines in blood circulation by qPCR showed significantly higher expression of IFNγ, IP10, TNFα, IL6, IL17A and chemokines CCL3, CCR1, CCR5, and CXCR3 in T1R as compared to NR. Frequencies of NKT-like cells (48.7 %) and NK cells (22.3 %) were found significantly higher in T1R in comparison to NR (36.9 %, 18.3 %, respectively) (p = 0.0001). Significantly lower levels of γδT cells (3.32 %) were observed in T1R in comparison to NR (5.16 %). The present study has provided evidence for the first time on the role of plausible unconventional T cells in the immunopathogenesis of T1R in leprosy.

Immunogenic arenavirus vector SIV vaccine reduces setpoint viral load in SIV-challenged rhesus monkeys.

HIV affects more than 38 million people worldwide. Although HIV can be effectively treated by lifelong combination antiretroviral therapy, only a handful of patients have been cured. Therapeutic vaccines that induce robust de novo immune responses targeting HIV proteins and latent reservoirs will likely be integral for functional HIV cure. Our study shows that immunization of naïve rhesus macaques with arenavirus-derived vaccine vectors encoding simian immunodeficiency virus (SIVSME543 Gag, Env, and Pol) immunogens is safe, immunogenic, and efficacious. Immunization induced robust SIV-specific CD8+ and CD4+ T-cell responses with expanded cellular breadth, polyfunctionality, and Env-binding antibodies with antibody-dependent cellular cytotoxicity. Vaccinated animals had significant reductions in median SIV viral load (1.45-log10 copies/mL) after SIVMAC251 challenge compared with placebo. Peak viral control correlated with the breadth of Gag-specific T cells and tier 1 neutralizing antibodies. These results support clinical investigation of arenavirus-based vectors as a central component of therapeutic vaccination for HIV cure.

A Peptide-Based Oscillator.

Living organisms are replete with rhythmic and oscillatory behavior at all levels, to the extent that oscillations have been termed as a defining attribute of life. Recent studies of synthetic oscillators that mimic such functions have shown decayed cycles in batch-mode reactions or sustained oscillatory kinetics under flow conditions. Considering the hypothesized functionality of peptides in early chemical evolution and their central role in current bio-nanotechnology, we now reveal a peptide-based oscillator. Oscillatory behavior was achieved by coupling coiled-coil-based replication processes as positive feedback to controlled initiation and inhibition pathways in a continuously stirred tank reactor (CSTR). Our results stress that assembly into the supramolecular structure and specific interactions with the replication substrates are crucial for oscillations. The replication-inhibition processes were first studied in batch mode, which produced a single damped cycle. Thereafter, combined experimental and theoretical characterization of the replication process in a CSTR under different flow and environmental (pH, redox) conditions demonstrated reasonably sustained oscillations. We propose that studies in this direction might pave the way to the design of robust oscillation networks that mimic the autonomous behavior of proteins in cells (e.g., in the cyanobacterial circadian clock) and hence hint at feasible pathways that accelerated the transition from simple peptides to extant enzymes.

Audiological, Phonatory and Cardiac Correlates of Individuals Exposed to Low-Frequency Noise or at Risk of Vibroacoustic Disease

Abstract Introduction Low-frequency noise (LFN) is hazardous to hearing. Long-term exposure to LFN may lead to vibroacoustic disease (VAD), which not only affects a specific organ but the physiological function of entire systems, such as the auditory, phonatory, respiratory, and cardiac systems. Moreover, VAD may lead to many psychological problems and hence affect the quality of life. Objective To investigate the adverse effects of LFN on hearing, acoustic and perceptual correlates of the voice, blood pressure, cardiac rate, and anxiety level. Method A total of 20 subjects exposed to LFN and 20 not exposed to LFN were included, and a detailed case history was recorded. The patients were submitted to pure tone audiometry, otoscopic examination, acoustic and perceptual analyses of the voice, maximum phonation time, and an assessment of the s/z ratio. We also assessed blood pressure, and the results of a voice-related quality of life questionnaire and of the Hamilton anxiety rating scale. Results The results indicate that LFN had an adverse impact on the high-frequency threshold. The present study found a significant difference in shimmer and harmonics-to-noise ratio (HNR) values. Few subjects had high blood pressure and showed the sign of anxiety on the Hamilton anxiety rating scale. Conclusion Low-frequency noise has adverse effects on entire systems of the body and causes many psychological issues, which, in turn negatively affect quality of life.

Are non-lactose-fermenting Escherichia coli important diarrhoeal pathogens in children and adults?

Introduction: Diarrhoeagenic Escherichia coli (DEC) remains one of the major causes of acute diarrhoea episodes in developing countries. The percentage of acute diarrhoea cases caused by DEC is 30-40 % in these countries. Approximately 10% of E. coli isolates obtained from stool specimens have been reported to be non-lactose-fermenting (NLF). The available literature is sparse regarding the pathogenicity of NLF E. coli causing infectious diarrhoea. Aim: We aimed to elucidate the importance of NLF E. coli in causing diarrhoea in both adults and children by detecting various DEC pathotypes among NLF E. coli in stool samples taken from gastroenteritis cases. Material and Methods: A total of 376 NLF E. coli isolates from 3110 stool samples from diarrhoea/gastroenteritis patients were included in the study. Up to three NLF colonies that were not confirmed as Vibrio cholerae , Aeromonas spp., Salmonella spp. or Shigella spp., but were identified as E. coli using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF), were carefully picked up from each MacConkey agar plate and then meticulously streaked onto freshly prepared, sterilized nutrient agar plates, and biochemical reactions were conducted. Multiplex PCR was conducted for the EAEC, EPEC, ETEC and EHEC pathotypes and PCR for the ipaH gene was conducted for EIEC. The disc diffusion method was used for antibiotic sensitivity testing. Results: Using multiplex PCR and ipaH PCR, a total of 63 pathotypes of DEC were obtained, with EAEC being the most predominant (n=31) followed by EIEC (n=22), EPEC (n=8) and ETEC (n=2). To further differentiate EIEC from Shigella , additional biochemical tests were performed, including acetate utilization, mucate and salicin fermentation, and aesculin hydrolysis. Antimicrobial susceptibility testing (AST) showed that maximum resistance was seen against ciprofloxacin (82.5 %) followed by ampicillin (77.8 %) and cotrimoxazole (68.2 %), and minimum resistance was seen against ertapenem (4.8 %). Conclusion: In our study two pathotypes (EAEC, EIEC) were predominant among NLF E. coli and these were not only important aetiological agents in children, but also in adults. Our study also sheds light on the epidemiology of EIEC, which is one of the most neglected DEC pathotypes, as hardly any microbiological laboratories process NLF E. coli for EIEC.

Audiological, Phonatory and Cardiac Correlates of Individuals Exposed to Low-Frequency Noise or at Risk of Vibroacoustic Disease.

Introduction Low-frequency noise (LFN) is hazardous to hearing. Long-term exposure to LFN may lead to vibroacoustic disease (VAD), which not only affects a specific organ but the physiological function of entire systems, such as the auditory, phonatory, respiratory, and cardiac systems. Moreover, VAD may lead to many psychological problems and hence affect the quality of life. Objective To investigate the adverse effects of LFN on hearing, acoustic and perceptual correlates of the voice, blood pressure, cardiac rate, and anxiety level. Method A total of 20 subjects exposed to LFN and 20 not exposed to LFN were included, and a detailed case history was recorded. The patients were submitted to pure tone audiometry, otoscopic examination, acoustic and perceptual analyses of the voice, maximum phonation time, and an assessment of the s/z ratio. We also assessed blood pressure, and the results of a voice-related quality of life questionnaire and of the Hamilton anxiety rating scale. Results The results indicate that LFN had an adverse impact on the high-frequency threshold. The present study found a significant difference in shimmer and harmonics-to-noise ratio (HNR) values. Few subjects had high blood pressure and showed the sign of anxiety on the Hamilton anxiety rating scale. Conclusion Low-frequency noise has adverse effects on entire systems of the body and causes many psychological issues, which, in turn negatively affect quality of life.

Outcomes of a hypertension care program based on task-sharing with private pharmacies: a retrospective study from two blocks in rural India.

Low density of formal care providers in rural India results in restricted and delayed access to standardized management of hypertension. Task-sharing with pharmacies, typically the first point of contact for rural populations, can bridge the gap in access to formal care and improve health outcomes. In this study, we implemented a hypertension care program involving task-sharing with twenty private pharmacies between November 2020 and April 2021 in two blocks of Bihar, India. Pharmacists conducted free hypertension screening, and a trained physician offered free consultations at the pharmacy. We calculated the number of subjects screened, initiated on treatment (enrolled) and the change in blood pressure using the data collected through the program application. Of the 3403 subjects screened at pharmacies, 1415 either reported having a history of hypertension or had elevated blood pressure during screening. Of these, 371 (26.22%) were enrolled in the program. Of these, 129 (34.8%) made at least one follow-up visit. For these subjects, the adjusted average difference in systolic and diastolic blood pressure between the screening and follow-up visits was -11.53 (-16.95 to -6.11, 95% CI) and -4.68 (-8.53 to -0.82, 95% CI) mmHg, respectively. The adjusted odds of blood pressure being under control in this group during follow-up visits compared to screening visit was 7.07 (1.29 to 12.85, 95% CI). Task-sharing with private pharmacies can lead to early detection and improved control of blood pressure in a resource-constrained setting. Additional strategies to increase patient screening and retention rates are needed to ensure sustained health benefits.

Emerging Bacterial Pathogens in the COVID-19 Era: Chryseobacterium gleum -A Case in Point.

Introduction In the ongoing severe acute respiratory syndrome coronavirus 2 pandemic, a long hospital stay and empirical broad-spectrum antibiotics make the patients prone to acquire nosocomial infections especially with unconventional organisms, and Chryseobacterium gleum is one such rare nosocomial pathogen. Methods The given study is a case-series-based study conducted from September 2020 to April 2021 in which clinically suspected pneumonia patients who recovered from coronavirus disease 2019 (COVID-19) were included. Results Seventeen C. gleum isolates were obtained in pure culture from the tracheal aspirates of nine COVID-19 patients (including repeat samples to rule out colonization) within a period of eight months (September 2020-April 2021). Our records showed that there has been an increase in the number of isolates of C. gleum obtained in respiratory samples in 2020. We also did a review of literature of all the cases of C. gleum pneumonia reported till now. Conclusion To the best of our knowledge, this is the first study reporting the isolation of this rare pathogen from COVID-19 patients with clinical significance in a large cohort of patients. Therefore, it becomes important to consider this pathogen as a significant cause of respiratory infections, especially in patients recovered post COVID-19.

Progress in vaccine development for infectious diseases-a Keystone Symposia report.

The COVID-19 pandemic has taught us many things, among the most important of which is that vaccines are one of the cornerstones of public health that help make modern longevity possible. While several different vaccines have been successful at stemming the morbidity and mortality associated with various infectious diseases, many pathogens/diseases remain recalcitrant to the development of effective vaccination. Recent advances in vaccine technology, immunology, structural biology, and other fields may yet yield insight that will address these diseases; they may also help improve societies' preparedness for future pandemics. On June 1-4, 2022, experts in vaccinology from academia, industry, and government convened for the Keystone symposium "Progress in Vaccine Development for Infectious Diseases" to discuss state-of-the-art technologies, recent advancements in understanding vaccine-mediated immunity, and new aspects of antigen design to aid vaccine effectiveness.