Hypothetical adhesin CAM87009.1 formulated in alum or biogenic silver nanoparticles protects mice from lethal infection by multidrug-resistant Acinetobacter baumannii.

Due to its antimicrobial resistance characteristics, the World Health Organization (WHO) classifies A. baumannii as one of the critical priority pathogens for the development of new therapeutic strategies. Vaccination has been approached as an interesting strategy to overcome the lack of effective antimicrobials and the long time required to develop and approve new drugs. In this study, we aimed to evaluate as a vaccine the hypothetical adhesin protein CAM87009.1 in its recombinant format (rCAM87009.1) associated with aluminum hydroxide (Alhydrogel®) or biogenic silver nanoparticles (bio-AgNP) as adjuvant components against lethal infection by A. baumannii MDR strain. Both vaccine formulations were administered in three doses intramuscularly in BALB/c murine models and the vaccinated animals were tested in a challenge assay with A. baumannii MDR strain (DL100). rCAM87009.1 protein associated with both adjuvants was able to protect 100 % of animals challenged with the lethal strain during the challenge period. After the euthanasia of the animals, no A. baumannii colonies were detected in the lungs of animals vaccinated with the rCAM87009.1 protein in both formulations. Since the first immunization, high IgG antibody titers were observed (1:819,200), with results being statistically similar in both vaccine formulations evaluated. rCAM87009.1 associated with both adjuvants was capable of inducing at least one class of isotypes associated with the processes of neutralization (IgG2b and IgA for bio-AgNP and Alhydrogel®, respectively), opsonization (IgG1 in both vaccines) and complement activation (IgM and IgG3 for bio-AgNP and Alhydrogel®, respectively). Furthermore, reduced tissue damage was observed in animals vaccinated with rCAM87009.1 + bio-AgNP when compared to animals vaccinated with Alhydrogel®. Our results indicate that the rCAM87009.1 protein associated with both bio-AgNP and Alhydrogel® are combinations capable of promoting immunity against infections caused by A. baumannii MDR. Additionally, we demonstrate the potential of silver nanoparticles as alternative adjuvant molecules to the use of aluminum salts.

Phosphate adsorption on dried alum sludge: Modeling and application to treatment of dairy effluents.

This study evaluates Alum sludge from drinking water treatment plants for the efficient and cost-effective removal of phosphates from aqueous solutions. Extensive characterization and batch experiments have established that optimal phosphate removal was achieved with a sludge dosage of 20 g L-1 (at an initial phosphate concentration of 100 mg L-1), a pH of 5, a temperature of 23 °C, and a stirring speed of 200 rpm. These conditions significantly reduced phosphate levels, ensuring compliance with legal discharge limits. The Langmuir isotherm, pseudo-second-order kinetic and intraparticle diffusion models best described the adsorption process, highlighting the spontaneous and endothermic nature of the phenomenon. The sludge effectively reduced phosphate concentrations to acceptable levels when applied to dairy effluents. This study underscores the potential of Alum sludge as a viable solution for phosphate management in environmental cleanup efforts.

The coagulation process for enveloped and non-enveloped virus removal in turbid water: Removal efficiencies, mechanisms and its application to SARS-CoV-2 Omicron BA.2.

The coagulation process has a high potential as a treatment method that can handle pathogenic viruses including emerging enveloped viruses in drinking water treatment process which can lower infection risk through drinking water consumption. In this study, a surrogate enveloped virus, bacteriophage Փ6, and surrogate non-enveloped viruses, including bacteriophage MS-2, T4, ՓX174, were used to evaluate removal efficiencies and mechanisms by the conventional coagulation process with alum, poly­aluminum chloride, and ferric chloride at pH 5, 7, and 9 in turbid water. Also, treatability of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a recent virus of global concern by coagulation was evaluated as SARS-CoV-2 can presence in drinking water sources. It was observed that an increase in the coagulant dose enhanced the removal efficiency of turbidity and viruses, and the condition that provided the highest removal efficiency of enveloped and non-enveloped viruses was 50 mg/L of coagulants at pH 5. In addition, the coagulation process was more effective for enveloped virus removal than for the non-enveloped viruses, and it demonstrated reduction of SARS-CoV-2 Omicron BA.2 over 0.83-log with alum. According to culture- and molecular-based assays (qPCR and CDDP-qPCR), the virus removal mechanisms were floc adsorption and coagulant inactivation. Through inactivation with coagulants, coagulants caused capsid destruction, followed by genome damage in non-enveloped viruses; however, damage to a lipid envelope is suggested to contribute to a great extend for enveloped virus inactivation. We demonstrated that conventional coagulation is a promising method for controlling emerging and re-emerging viruses in drinking water.

Structure-Activity Relationships toward the Identification of a High-Potency Selective Human Toll-like Receptor-7 Agonist.

Toll-like receptor (TLR)-7 agonists are immunostimulatory vaccine adjuvants. A systematic structure-activity relationship (SAR) study of TLR7-active 1-benzyl-2-butyl-1H-imidazo[4,5-c]quinolin-4-amine led to the identification of a potent hTLR7-specific p-hydroxymethyl IMDQ 23 with an EC50 value of 0.22 µM. The SAR investigation also resulted in the identification of TLR7 selective carboxamide 12 with EC50 values of 0.32 µM for hTLR7 and 18.25 µM for hTLR8. In the vaccination study, TLR7-specific compound 23 alone or combined with alum (aluminum hydroxide wet gel) showed adjuvant activity for a spike protein immunogen in mice, with enhanced anti-spike antibody production. Interestingly, the adjuvant system comprising carboxamide 12 and alum showed prominent adjuvant activity with high levels of IgG1, IgG2b, and IgG2c in immunized mice, confirming a balanced Th1/Th2 response. In the absence of any apparent toxicity, the TLR7 selective agonists in combination with alum may make a suitable vaccine adjuvant.

Differential protective impact of peptide vaccine formulae targeting the lung- and liver-stage of challenge Schistosoma mansoni infection in mice.

The study aimed to elicit protective immune responses against murine schistosomiasis mansoni at the parasite lung- and liver stage. Two peptides showing amino acid sequence similarity to gut cysteine peptidases, which induce strong memory immune effectors in the liver, were combined with a peptide based on S. mansoni thioredoxin peroxidase (TPX), a prominent lung-stage schistosomula excretory-secretory product, and alum as adjuvant. Only one of the 2 cysteine peptidases-based peptides in a multiple antigenic peptide construct (MAP-3 and MAP-4) appeared to adjuvant protective immune responses induced by the TPX peptide in a MAP form. Production of TPX MAP-specific IgG1 serum antibodies, and increase in lung interleukin-1 (IL-1), uric acid, and reactive oxygen species (ROS) content were associated with significant (P < 0.05) 50 % reduction in recovery of lung-stage larvae. Increase in lung triglycerides and cholesterol levels appeared to provide the surviving worms with nutrients necessary for a stout double lipid bilayer barrier at the parasite-host interface. Surviving worms-released products elicited memory responses to the MAP-3 immunogen, including production of specific IgG1 antibodies and increase in liver IL-33 and ROS. Reduction in challenge worm burden recorded 45 days post infection did not exceed 48 % associated with no differences in parasite egg counts in the host liver and small intestine compared to unimmunized adjuvant control mice. Alum adjuvant assisted the second peptide, MAP-4, in production of IgG1, IgG2a, IgG2b and IgA specific antibodies and increase in liver ROS, but with no protective potential, raising doubt about the necessity of adjuvant addition. Accordingly, different vaccine formulas containing TPX MAP and 1, 2 or 3 cysteine peptidases-derived peptides with or without alum were used to immunize parallel groups of mice. Compared to unimmunized control mice, significant (P < 0.05 to < 0.005) 22 to 54 % reduction in worm burden was recorded in the different groups associated with insignificant changes in parasite egg output. The results together indicated that a schistosomiasis vaccine able to entirely prevent disease and halt its transmission still remains elusive.

The orientation of CpG conjugation on aluminum oxyhydroxide nanoparticles determines the immunostimulatory effects of combination adjuvants.

In subunit vaccines, aluminum salts (Alum) are commonly used as adjuvants, but with limited cellular immune responses. To overcome this limitation, CpG oligodeoxynucleotides (ODNs) have been used in combination with Alum. However, current combined usage of Alum and CpG is limited to linear mixtures, and the underlying interaction mechanism between CpG and Alum is not well understood. Thus, we propose to chemically conjugate Alum nanoparticles and CpG (with 5' or 3' end exposed) to design combination adjuvants. Our study demonstrates that compared to the 3'-end exposure, the 5'-end exposure of CpG in combination adjuvants (Al-CpG-5') enhances the activation of bone-marrow derived dendritic cells (BMDCs) and promotes Th1 and Th2 cytokine secretion. We used the SARS-CoV-2 receptor binding domain (RBD) and hepatitis B surface antigen (HBsAg) as model antigens to demonstrate that Al-CpG-5' enhanced antigen-specific antibody production and upregulated cytotoxic T lymphocyte markers. Additionally, Al-CpG-5' allows for coordinated adaptive immune responses even at lower doses of both CpG ODNs and HBsAg antigens, and enhances lymph node transport of antigens and activation of dendritic cells, promoting Tfh cell differentiation and B cell activation. Our novel Alum-CPG strategy points the way towards broadening the use of nanoadjuvants for both prophylactic and therapeutic vaccines.

Immunogenicity and safety of SARS-CoV-2 recombinant protein subunit vaccine (IndoVac) adjuvanted with alum and CpG 1018 in Indonesian adults: A phase 3, randomized, active-controlled, multicenter trial.

BACKGROUND: Bio Farma has developed a recombinant protein subunit vaccine (IndoVac) that is indicated for active immunization in population of all ages. This article reported the results of the phase 3 immunogenicity and safety study in Indonesian adults aged 18 years and above. METHODS: We conducted a randomized, active-controlled, multicenter, prospective intervention study to evaluate the immunogenicity and safety of IndoVac in adults aged 18 years and above. Participants who were SARS-CoV-2 vaccine-naïve received two doses of either IndoVac or control (Covovax) with 28 days interval between doses and were followed up until 12 months after complete vaccination. RESULTS: A total of 4050 participants were enrolled from June to August 2022 and received at least one dose of vaccine. The geometric mean ratio (GMR) of neutralizing antibody at 14 days after the second dose was 1.01 (95 % confidence interval (CI) 0.89-1.16), which met the WHO non-inferiority criteria for immunobridging (95 % CI lower bound > 0.67). The antibody levels were maintained through 12 months after the second dose. The incidence rate of adverse events (AEs) were 27.95 % in IndoVac group and 32.15 % in Covovax group with mostly mild intensity (27.70 %). The most reported solicited AEs were pain (14.69 %) followed by myalgia (7.48 %) and fatigue (6.77 %). Unsolicited AEs varied, with each of the incidence rate under 5 %. There were no serious AEs assessed as possibly, probably, or likely related to vaccine. CONCLUSIONS: IndoVac in adults showed favourable safety profile and elicited non-inferior immune response to Covovax. (ClinicalTrials.gov: NCT05433285, Indonesian Clinical Research Registry: INA-R5752S9).

Remediation of sediments contaminated by harmful heavy metals using aluminum sulfate: Sustainable approach for practical applications.

Chemical washing could be suitable for the remediation of marine sediments contaminated with harmful heavy metals. Considering green and sustainable remediation (GSR), the application of aluminum sulfate (AS) is intended to reduce the costs and environmental impacts. We extracted harmful heavy metals from manganese nodules using an ion exchange mechanism that occurs when AS dissociates in water. AS in the range from 2 % to 5 % was used. The remediation efficiencies using 5 % AS were found to be the highest, at 91.8 % for Ni and ≥ 100 % for other harmful heavy metals. The Pearson's coefficient evaluation showed that increasing elapsed time did not significantly affect the extraction of harmful heavy metals. Pollutants in post-processing products may not cause secondary pollutions if solidification/stabilization and additional treatments are used. Our results can serve as fundamental data for the actual remediation processes using AS not only for deep-sea mining tailings but also contaminated marine sediments.

Evaluation of different types of adjuvants in a malaria transmission-blocking vaccine.

Adjuvants are critical components for vaccines, which enhance the strength and longevity of the antibody response and influence the types of immune response. Limited research has been conducted on the immunogenicity and protective efficacy of various adjuvants in malaria transmission-blocking vaccines (TBVs). In this study, we formulated a promising TBV candidate antigen, the P. berghei ookinete surface antigen PSOP25, with different types of adjuvants, including the TLR4 agonist monophosphoryl lipid A (MPLA), the TLR9 agonist cytosine phosphoguanosine oligodeoxynucleotides (CpG ODN 1826) (CpG), a saponin adjuvant QS-21, aluminum hydroxide (Alum), and two combination adjuvants MPLA + QS-21 and QS-21 + CpG. We demonstrated that adjuvanted vaccines results in elevated elicited antibody levels, increased proliferation of plasma cells, and efficient formation of germinal centers (GCs), leading to enhanced long-term protective immune responses. Furthermore, CpG group exhibited the most potent inhibition of ookinete formation and transmission-blocking activity. We found that the rPSOP25 with CpG adjuvant was more effective than MPLA, QS-21, MPLA + QS-21, QS-21 + CpG adjuvants in dendritic cells (DCs) activation and differentiation. Additionally, the CpG adjuvant elicited more rubust immune memory response than Alum adjuvant. CpG and QS-21 adjuvants could activate the Th1 response and promote the secretion of IFN-γ and TNF-α. PSOP25 induced a higher number of Tfh cells in splenocytes when combined with MPLA, CpG, and QS-21 + CpG; and there was no increase in these cell populations when PSOP25 was administered with Alum. In conclusion, CpG may confer enhanced efficacy for the rPSOP25 vaccine, as evidenced by the ability of the elicited antisera to induce protective immune responses and improved transmission-blocking activity.

Safety and immunogenicity of a subtype C ALVAC-HIV (vCP2438) vaccine prime plus bivalent subtype C gp120 vaccine boost adjuvanted with MF59 or alum in healthy adults without HIV (HVTN 107): A phase 1/2a randomized trial.

BACKGROUND: Adjuvants are widely used to enhance and/or direct vaccine-induced immune responses yet rarely evaluated head-to-head. Our trial directly compared immune responses elicited by MF59 versus alum adjuvants in the RV144-like HIV vaccine regimen modified for the Southern African region. The RV144 trial of a recombinant canarypox vaccine vector expressing HIV env subtype B (ALVAC-HIV) prime followed by ALVAC-HIV plus a bivalent gp120 protein vaccine boost adjuvanted with alum is the only trial to have shown modest HIV vaccine efficacy. Data generated after RV144 suggested that use of MF59 adjuvant might allow lower protein doses to be used while maintaining robust immune responses. We evaluated safety and immunogenicity of an HIV recombinant canarypox vaccine vector expressing HIV env subtype C (ALVAC-HIV) prime followed by ALVAC-HIV plus a bivalent gp120 protein vaccine boost (gp120) adjuvanted with alum (ALVAC-HIV+gp120/alum) or MF59 (ALVAC-HIV+gp120/MF59) or unadjuvanted (ALVAC-HIV+gp120/no-adjuvant) and a regimen where ALVAC-HIV+gp120 adjuvanted with MF59 was used for the prime and boost (ALVAC-HIV+gp120/MF59 coadministration). METHODS AND FINDINGS: Between June 19, 2017 and June 14, 2018, 132 healthy adults without HIV in South Africa, Zimbabwe, and Mozambique were randomized to receive intramuscularly: (1) 2 priming doses of ALVAC-HIV (months 0 and 1) followed by 3 booster doses of ALVAC-HIV+gp120/MF59 (months 3, 6, and 12), n = 36; (2) 2 priming doses of ALVAC-HIV (months 0 and 1) followed by 3 booster doses of ALVAC-HIV+gp120/alum (months 3, 6, and 12), n = 36; (3) 4 doses of ALVAC-HIV+gp120/MF59 coadministered (months 0, 1, 6, and 12), n = 36; or (4) 2 priming doses of ALVAC-HIV (months 0 and 1) followed by 3 booster doses of ALVAC-HIV+gp120/no adjuvant (months 3, 6, and 12), n = 24. Primary outcomes were safety and occurrence and mean fluorescence intensity (MFI) of vaccine-induced gp120-specific IgG and IgA binding antibodies at month 6.5. All vaccinations were safe and well-tolerated; increased alanine aminotransferase was the most frequent related adverse event, occurring in 2 (1.5%) participants (1 severe, 1 mild). At month 6.5, vaccine-specific gp120 IgG binding antibodies were detected in 100% of vaccinees for all 4 vaccine groups. No significant differences were seen in the occurrence and net MFI of vaccine-specific IgA responses between the ALVAC-HIV+gp120/MF59-prime-boost and ALVAC-HIV+gp120/alum-prime-boost groups or between the ALVAC-HIV+gp120/MF59-prime-boost and ALVAC-HIV+gp120/MF59 coadministration groups. Limitations were the relatively small sample size per group and lack of evaluation of higher gp120 doses. CONCLUSIONS: Although MF59 was expected to enhance immune responses, alum induced similar responses to MF59, suggesting that the choice between these adjuvants may not be critical for the ALVAC+gp120 regimen. TRIAL REGISTRATION: HVTN 107 was registered with the South African National Clinical Trials Registry (DOH-27-0715-4894) and ClinicalTrials.gov (NCT03284710).

An inactivated whole-virion vaccine for Enterovirus D68 adjuvanted with CpG ODN or AddaVax elicits potent protective immunity in mice.

Enterovirus D68 (EV-D68), a pathogen that causes respiratory symptoms, mainly in children, has been implicated in acute flaccid myelitis, which is a poliomyelitis-like paralysis. Currently, there are no licensed vaccines or treatments for EV-D68 infections. Here, we investigated the optimal viral inactivation reagents, vaccine adjuvants, and route of vaccination in mice to optimize an inactivated whole-virion (WV) vaccine against EV-D68. We used formalin, ß-propiolactone (BPL), and hydrogen peroxide as viral inactivation reagents and compared their effects on antibody responses. Use of any of these three viral inactivation reagents effectively induced neutralizing antibodies. Moreover, the antibody response induced by the BPL-inactivated WV vaccine was enhanced when adjuvanted with cytosine phosphoguanine oligodeoxynucleotide (CpG ODN) or AddaVax (MF59-like adjuvant), but not with aluminum hydroxide (alum). Consistent with the antibody response results, the protective effect of the inactivated WV vaccine against the EV-D68 challenge was enhanced when adjuvanted with CpG ODN or AddaVax, but not with alum. Further, while the intranasal inactivated WV vaccine induced EV-D68-specific IgA antibodies in the respiratory tract, it was less protective against EV-D68 challenge than the injectable vaccine. Thus, an injectable inactivated EV-D68 WV vaccine prepared with appropriate viral inactivation reagents and an optimal adjuvant is a promising EV-D68 vaccine.

Alum/CpG adjuvant promotes immunogenicity of inactivated SARS-CoV-2 Omicron vaccine through enhanced humoral and cellular immunity.

The SARS-CoV-2 Omicron variant, which was classified as a variant of concern (VOC) by the World Health Organization on 26 November 2021, has attracted worldwide attention for its high transmissibility and immune evasion ability. The existing COVID-19 vaccine has been shown to be less effective in preventing Omicron variant infection and symptomatic infection, which brings new challenges to vaccine development and application. Here, we evaluated the immunogenicity and safety of an Omicron variant COVID-19 inactivated vaccine containing aluminum and CpG adjuvants in a variety of animal models. The results showed that the vaccine candidate could induce high levels of neutralizing antibodies against the Omicron variant virus and binding antibodies, and significantly promoted cellular immune response. Meanwhile, the vaccine candidate was safe. Therefore, it provided more foundation for the development of aluminum and CpG as a combination adjuvant in human vaccines.

Phosphorus fractions and speciation in an alkaline, manured soil amended with alum, gypsum, and Epsom salt.

Snowmelt runoff is a dominant pathway of phosphorus (P) losses from agricultural lands in cold climatic regions. Soil amendments effectively reduce P losses from soils by converting P to less soluble forms; however, changes in P speciation in cold climatic regions with fall-applied amendments have not been investigated. This study evaluated P composition in soils from a manured field with fall-amended alum (Al2(SO4)3·18H2O), gypsum (CaSO4·2H2O), or Epsom salt (MgSO4·7H2O) using three complementary methods: sequential P fractionation, scanning electron microscopy with energy-dispersive X-rays (SEM-EDX) spectroscopy, and P K-edge X-ray absorption near-edge structure spectroscopy (XANES). Plots were established in an annual crop field in southern Manitoba, Canada, with unamended and amended (2.5 Mg ha-1) treatments having four replicates in 2020 fall. Soil samples (0-10 cm) taken from each plot soon after spring snowmelt in 2021 were subjected to P fractionation. A composite soil sample for each treatment was analyzed using SEM-EDX and XANES. Alum- and Epsom salt-treated soils had significantly greater residual P fraction with a higher proportion of apatite-like P and a correspondingly lower proportion of P sorbed to calcite (CaCO3) than unamended and gypsum-amended soils. Backscattered electron imaging of SEM-EDX revealed that alum- and Epsom salt-amended treatments had P-enriched microsites frequently associated with aluminum (Al), iron (Fe), magnesium (Mg), and calcium (Ca), which was not observed in other treatments. Induced precipitation of apatite-like species may have been responsible for reduced P loss to snowmelt previously reported with fall application of amendments.

Adjuvant screening of the Senecavirus A inactivated vaccine in mice and evaluation of its immunogenicity in pigs.

BACKGROUND: Senecavirus A (SVA) causes an emerging vesicular disease (VD) with clinical symptoms indistinguishable from other vesicular diseases, including vesicular stomatitis (VS), foot-and-mouth disease (FMD), and swine vesicular disease (SVD). Currently, SVA outbreaks have been reported in Canada, the U.S.A, Brazil, Thailand, Vietnam, Colombia, and China. Based on the experience of prevention and control of FMDV, vaccines are the best means to prevent SVA transmission. RESULTS: After preparing an SVA inactivated vaccine (CH-GX-01-2019), we evaluated the immunogenicity of the SVA inactivated vaccine mixed with Imject® Alum (SVA + AL) or Montanide ISA 201 (SVA + 201) adjuvant in mice, as well as the immunogenicity of the SVA inactivated vaccine combined with Montanide ISA 201 adjuvant in post-weaned pigs. The results of the mouse experiment showed that the immune effects in the SVA + 201 group were superior to that in the SVA + AL group. Results from pigs immunized with SVA inactivated vaccine combined with Montanide ISA 201 showed that the immune effects were largely consistent between the SVA-H group (200 µg) and SVA-L group (50 µg); the viral load in tissues and blood was significantly reduced and no clinical symptoms occurred in the vaccinated pigs. CONCLUSIONS: Montanide ISA 201 is a better adjuvant choice than the Imject® Alum adjuvant in the SVA inactivated vaccine preparation, and the CH-GX-01-2019 SVA inactivated vaccine can provide effective protection for pigs.

Development and preclinical evaluation of equine-derived hyperimmune serum against SARS-CoV-2 infection in K-18 hACE2 transgenic (Tg) mice.

This study aimed to develop an equine-derived hyperimmune serum against SARS-CoV-2 and evaluate its efficacy as a potential immunotherapy tool for the treatment of known and potential variants of COVID-19 in preclinical trials. The novelty of this study is the whole virus and ALUM gel adjuvant formula. The horses were immunized using a whole inactivated SARS-CoV-2 antigen, and the final purified hyperimmune serum showed high plaque reduction neutralization (PRNT 50) neutralizing titers. The efficacy of the hyperimmune serum was evaluated histopathologically and biochemically in the lungs, hearts, and serum of K18 hACE2 transgenic mice (n=45), which is an accepted model organism for SARS-CoV-2 studies and was challenged with live SARS-CoV-2. Serum treatment improved the general condition, resulting in lower levels of proinflammatory cytokines in the blood plasma, as well as reduced viral RNA titers in the lungs and hearts. Additionally, it reduced oxidative stress significantly and lessened the severity of interstitial pneumonia in the lungs when compared to infected positive controls. The study concluded that equine-derived anti-SARS-CoV-2 antibodies could be used for COVID-19 prevention and treatment, especially in the early stages of the disease and in combination with antiviral drugs and vaccines. This treatment will benefit special patient populations such as immunocompromised individuals, as specific antibodies against SARS-CoV-2 can neutralize the virus before it enters host cells. The rapid and cost-effective production of the serum allows for its availability during the acute phase of the disease, making it a critical intervention in preventing the spread of the disease and saving lives in new variants where a vaccine is not yet developed.

Efficacy of adjuvant-associated COVID-19 vaccines against SARS-CoV-2 variants of concern in randomized controlled trials: A systematic review and meta-analysis.

BACKGROUND: Adjuvants may enhance the efficacy of vaccines. however, the efficacy of adjuvant-associated COVID-19 vaccines (ACVs) remains unclear since the emergence of the COVID-19 pandemic. This study aimed to address this gap by conducting a systematic review and meta-analysis of the efficacy of ACVs against Severe Acute Respiratory Syndrome Coronavirus 2 CoV (SARS-CoV-2) variants of concern (VOC). METHODS: A systematic search was conducted of randomized controlled trials (RCTs) evaluating the vaccine efficacy (VE) of ACVs against VOC (alpha, beta, gamma, delta, or Omicron), up to May 27, 2023. The DerSimonian-Laird random-effects model was used to assess VE with 95% confidence intervals (CI) through meta-analysis. Cochrane Risk of Bias tools were used to assess the risk of bias in RCTs. RESULTS: Eight RCTs with 113,202 participants were included in the analysis, which incorporated 4 ACVs [Matrix-M (NVX-CoV2373), Alum (BBV152), CpG-1018/Alum (SCB-2019), and AS03 (CoVLP]). The pooled efficacy of full vaccination with ACVs against VOC was 88.0% (95% CI: 83.0-91.5). Full vaccination was effective against Alpha, Beta, Delta, and Gamma variants, with VE values of 93.66% (95% CI: 86.5-100.74), 64.70% (95% CI: 41.87-87.54), 75.95% (95% CI: 67.9-83.99), and 91.26% (95% CI: 84.35-98.17), respectively. Currently, there is a lack of RCT evidence regarding the efficacy of ACVs against the Omicron variant. CONCLUSION: In this meta-analysis, it should be that full vaccination with ACVs has high efficacy against Alpha or Gamma variants and moderate efficacy against Beta and Delta variants. Notably, with the exception of the aluminum-adjuvanted vaccine, the other ACVs had moderate to high efficacy against the SARS-CoV-2 variant. This raises concerns about the effectiveness of ACVs booster vaccinations against Omicron.

Monophosphoryl lipid A as a co-adjuvant in methicillin-resistant Staphylococcus aureus vaccine development: improvement of immune responses in a mouse model of infection.

To increase the effectiveness of methicillin-resistant Staphylococcus aureus vaccines (MRSA), a new generation of immune system stimulating adjuvants is necessary, along with other adjuvants. In some vaccines, monophosphoryl lipid A (MPLA) as a toll-like receptor 4 agonist is currently used as an adjuvant or co-adjuvant. MPLA could increase the immune response and vaccine immunogenicity. The current investigation assessed the immunogenicity and anti-MRSA efficacy of recombinant autolysin formulated in MPLA and Alum as co-adjuvant/adjuvant. r-Autolysin was expressed and purified by Ni-NTA affinity chromatography and characterized by SDS-PAGE. Then, the vaccine candidate formulation in MPLAs and Alum was prepared. To investigate the immunogenic responses, total IgG, isotype (IgG1 and IgG2a) levels, and cytokines (IL-4, IL-12, TNF-α, and IFN-γ) profiles were evaluated by ELISA. Also, the bacterial burden in internal organs, opsonophagocytosis, survival rate, and pathobiology changes was compared among the groups. Results demonstrated that mice immunized with the r-Autolysin + Alum + MPLA Synthetic and r-Autolysin + Alum + MPLA Biologic led to increased levels of opsonic antibodies, IgG1, IgG2a isotype as well as increased levels of cytokines profiles, as compared with other experimental groups. More importantly, mice immunized with MPLA and r-Autolysin exhibited a decrease in mortality and bacterial burden, as compared with the control group. The highest level of survival was seen in the r-Autolysin + Alum + MPLA Synthetic group. We concluded that both MPLA forms, synthetic and biological, are reliable candidates for immune response improvement against MRSA infection.

Use of wastewater alum-coagulation sludge as a phosphorus fertiliser - a mini review.

The use of aluminium (Al) salts, particularly alum, in coagulation is a widespread and conventional treatment method for eliminating pollutants, including phosphorus (P) which can cause eutrophication, from wastewater. However, a significant challenge of this process is the substantial amount of sludge generated, necessitating proper disposal. Historically, land disposal has been a common practice, but it poses potential issues for plant life on these lands. Despite the associated drawbacks, sludge contains elevated concentrations of vital plant nutrients like P and nitrogen, presenting an opportunity for beneficial use in agriculture. Given the imminent scarcity of P fertilizers due to the eventual depletion of high-grade P ores, this review explores the potential advantages and challenges of utilizing Al sludge as a P source for plants and proposes measures for its beneficial application. One primary concern with land application of Al sludge is its high levels of soluble Al, known to be toxic to plants, particularly in acidic soils. Another issue arises from the elevated Al concentration is P fixation and subsequently reducing P uptake by plants. To address these issues, soil treatment options such as lime, gypsum, and organic matter can be employed. Additionally, modifying the coagulation process by substituting part of the Al salts with cationic organic polymers proves effective in reducing the Al content of the sludge. The gradual release of P from sludge into the soil over time proves beneficial for plants with extended growth periods.

Immunogenicity and safety in rabbits of a Clostridioides difficile vaccine combining novel toxoids and a novel adjuvant.

Clostridioides difficile infection (CDI) is a serious healthcare-associated disease, causing symptoms such as diarrhea and pseudomembranous colitis. The major virulence factors responsible for the disease symptoms are two secreted cytotoxic proteins, TcdA and TcdB. A parenteral vaccine based on formaldehyde-inactivated TcdA and TcdB supplemented with alum adjuvant, has previously been investigated in humans but resulted in an insufficient immune response. In search for an improved response, we investigated a novel toxin inactivation method and a novel, potent adjuvant. Inactivation of toxins by metal-catalyzed oxidation (MCO) was previously shown to preserve neutralizing epitopes and to annihilate reversion to toxicity. The immunogenicity and safety of TcdA and TcdB inactivated by MCO and combined with a novel carbohydrate fatty acid monosulphate ester-based (CMS) adjuvant were investigated in rabbits. Two or three intramuscular immunizations generated high serum IgG and neutralizing antibody titers against both toxins. The CMS adjuvant increased antibody responses to both toxins while an alum adjuvant control was effective only against TcdA. Systemic safety was evaluated by monitoring body weight, body temperature, and analysis of red and white blood cell counts shortly after immunization. Local safety was assessed by histopathologic examination of the injection site at the end of the study. Body weight gain was constant in all groups. Body temperature increased up to 1 ˚C one day after the first immunization but less after the second or third immunization. White blood cell counts, and percentage of neutrophils increased one day after immunization with CMS-adjuvanted vaccines, but not with alum. Histopathology of the injection sites 42 days after the last injection did not reveal any abnormal tissue reactions. From this study, we conclude that TcdA and TcdB inactivated by MCO and combined with CMS adjuvant demonstrated promising immunogenicity and safety in rabbits and could be a candidate for a vaccine against CDI.

Enhanced immunogenicity and protective efficacy in mice following a Zika DNA vaccine designed by modulation of membrane-anchoring regions and its association to adjuvants.

Zika virus (ZIKV) is a re-emerging pathogen with high morbidity associated to congenital infection. Despite the scientific advances since the last outbreak in the Americas, there are no approved specific treatment or vaccines. As the development of an effective prophylactic approach remains unaddressed, DNA vaccines surge as a powerful and attractive candidate due to the efficacy of sequence optimization in achieving strong immune response. In this study, we developed four DNA vaccine constructs encoding the ZIKV prM/M (pre-membrane/membrane) and E (envelope) proteins in conjunction with molecular adjuvants. The DNA vaccine candidate (called ZK_ΔSTP), where the entire membrane-anchoring regions were completely removed, was far more immunogenic compared to their counterparts. Furthermore, inclusion of the tPA-SP leader sequence led to high expression and secretion of the target vaccine antigens, therefore contributing to adequate B cell stimulation. The ZK_ΔSTP vaccine induced high cellular and humoral response in C57BL/6 adult mice, which included high neutralizing antibody titers and the generation of germinal center B cells. Administration of ZK-ΔSTP incorporating aluminum hydroxide (Alum) adjuvant led to sustained neutralizing response. In consistency with the high and long-term protective response, ZK_ΔSTP+Alum protected adult mice upon viral challenge. Collectively, the ZK_ΔSTP+Alum vaccine formulation advances the understanding of the requirements for a successful and protective vaccine against flaviviruses and is worthy of further translational studies.