Booster Dose Research Articles

Effectiveness Of Local Cold Application, Manual Pressure, Shot Blocker And Standard Injection Procedure During Tetanus Diphtheria (Td) Vaccine Booster Immunization In Reducing Pain At The Intramuscular Injection Site Of Children Studying In Selected Schools: A Systematic Review

Effectiveness Of Local Cold Application, Manual Pressure, Shot Blocker And Standard Injection Procedure During Tetanus Diphtheria (Td) Vaccine Booster Immunization In Reducing Pain At The Intramuscular Injection Site Of Children Studying In Selected Schools: A Systematic Review

PSV-10 Vaccination of beef cattle to reduce enteric methane emissions

Abstract Livestock methane (CH4) emissions total over 3 billion tonnes per year of carbon dioxide equivalents (CO2e) and are responsible for approximately 6% of total annual greenhouse gas emissions. The contribution of livestock CH4 emissions are only to be exacerbated as the global demand for meat and dairy products increases. Greater than 75% of livestock CH4 emissions are generated in dispersed production environments (e.g., cow-calf and stocker segments), which are not addressable by methane mitigation strategies requiring constant inputs. Thus, strategies that fit into standard agronomic practices, in particular dispersed production environments, are urgently needed to address the increasing carbon footprint associated with livestock production. Methane-reducing vaccines are a promising solution for addressing this need, due to their longevity of action, low cost, and ease of integration into standard agronomic practices, which could lower the barrier for adoption. Thus, this study aimed to assess the effects of a prototype vaccine on total and antigen-specific immune response, CH4 yield, and average daily gain (ADG) in cattle. Angus crossbred steers [n = 20; initial body weight (BW) = 537 ± 15 kg) fed on a high-forage diet were randomly assigned to either placebo- or vaccine-treated groups blocked by BW, breed, and feed intake. Steers were subcutaneously inoculated (2 mL dose) in the anterior region of the neck. Blood and saliva samples were collected, and total sera and salivary immunoglobulin (Ig) G and IgA were quantified using ELISA (Bethyl laboratories, Montgomery, TX). Antigen-specific sera IgG was measured using ELISA. Daily CH4 emissions and dry matter intake (DMI) were measured using GreenFeed systems (C-Lock Inc. Rapid City, SD) and GrowSafe feed bunks (Vytelle, Lenexa, KS), respectively. Body weights were recorded bi-weekly. Total sera IgA and IgG did not differ between the placebo-treated and vaccinated steers (P = 0.584 and P = 0.425, respectively), nor did total salivary IgA and IgG (P = 0.577 and P = 0.548, respectively). However, antigen-specific sera IgG did significantly increase following booster vaccination in the vaccinated steers, as compared with placebo-treated steers (d 0 vs. d 28; P < 0.001). CH4 yield was significantly reduced in vaccinated steers following booster vaccination despite significantly increasing in placebo-treated steers over the same period (P = 0.002). This reduction in CH4 yield was not associated with a reduction in DMI nor ADG (P = 0.181 and P = 0.314, respectively), suggesting that vaccination did not negatively affect treated animals. These findings underscore the potential of vaccine-based solutions to mitigate the environmental impact of livestock CH4 emissions, especially from dispersed production environments where current options for mitigation strategies are limited.

PSVIII-9 Effects of growth implants and timing of vaccination on calf immunity and growth performance

Abstract This study assessed calf growth performance and blood parameters of beef calves under different growth implants and timing of vaccination protocols. Crossbreed beef calves (n = 59) were stratified by birth body weight (BW) and age (41 ± 5.2 kg of BW and 70 ± 8 d of age) and randomly assigned in a split-plot design with implant strategy as the main plot and timing of vaccination as the subplot. The main plot (treatment) consisted of 3 implant strategies: 1) Synovex C (SC; n = 20; 100 mg progesterone/10 mg estradiol benzoate, or 2) Synovex One Grower (SG; n = 19; 150 mg trenbolone acetate and 21 mg estradiol benzoate; or 3) no implant (CON; n = 20). Subplot treatments were the timing of vaccination booster against bovine respiratory disease pathogens on 1) weaning (WV; n = 29) or 2) 7-d post-weaning (PWV; n = 30). Cow-calf pairs were treated alike in a single pasture during the pre-weaning phase, receiving the same vaccine (Bovi-Shield Gold One Shot and Ultrabac 7) on d 0 (implantation day) and booster time (WV or PWV). After weaning (approximately 187 d of age), calves were allocated in a single pen receiving ad libitum hay until d 60 post-weaning. Body weight and blood were collected on d 0, weaning, d 0 and 28 relative to vaccination booster, and d 60 post-weaning. Blood was collected to determine insulin-like growth factor (IGF-1), cortisol, and leptin concentrations and to perform a complete blood cell count. WV calves had decreased cortisol concentrations on booster day and 28 d post-vaccine (P = 0.01). Regardless of implant treatment, calves tended to have decreased IGF-1 concentrations 28-d post-vaccine booster (P = 0.09). An effect of treatment (P < 0.01) was detected for lymphocyte counts, with CON having greater concentrations vs. SG and SC calves. A treatment × timing of vaccination (P < 0.01) interaction was detected for monocyte counts, where SG-PWV calves had the greatest concentrations. A treatment effect (P < 0.02) was observed for eosinophil percentage, where SG had reduced percentages than CON, while SC was intermediate. An effect of treatment was detected for leptin (P < 0.01), with SG calves having the least, CON being intermediate, and SC the greatest concentrations. From d 0 to 60 d post-weaning, SG tended to have greater ADG (P ≤ 0.07) compared with CON, while SC was intermediate. On d 28 and d 35 post-weaning, calves implanted with SG were heavier (P ≤ 0.04) than the CON but not than SC. In summary, this study demonstrates that growth implants and timing of vaccination significantly affect both physiological parameters and growth performance in beef calves. Implanting calves with Synovex One Grower resulted in improved growth performance.

PSLBII-1 Enhancing cattle health and performance through targeted supplement optimization and evaluation

Abstract Our objective is to evaluate and optimize Bovi-MV formulation through its effect on serum mineral/vitamin (M/V) concentrations in cattle and develop a systems approach to oral M/V supplementation through the lifecycle of beef cattle to determine the best management strategy to help reduce M/V deficiencies in young and mature animals. Cow/calf pairs (n = 300 over 2 yr) and follow the calves to harvest late in yr 2. The research is timed to coincide with typical management handling processes (e.g., vaccination of cows before calving and calf processing after birth, before pasture, at weaning time, on induction to the feedlot, and at reimplanting). The calf herd will be divided at birth into treatment (calves whose dams received BoviMV supplement) and control (~150 calves per group). Vitaferst-Care will be provided to the treatment group at processing (vaccination, antiparasitic application) before going to grass (~ 3 mo of age). Bovi-MV will only be given to the treatment group. All calves will be administered a tracer vaccine to assess their immune response. Blood samples will be collected from all calves for antibody titer testing at weaning (~ 6 mo of age). The treatment calves will also receive a booster dose of Bovi-MV at that time. Approximately 90 d after weaning (~ 9 mo of age) antibody titer will be determined immune response was. Calf morbidity, mortality, and performance (average daily gain) will be monitored in the feedlot. An accredited lab will conduct M/V blood analysis; antibody titer testing will be done at a Lakeland College lab. Based on MV and titer to the Bovi-MV supplement and tracer vaccine, the formulation of the Bovi-MV will be evaluated, and recommendations will be made. Based on results from two previous studies evaluating M/V blood concentrations in cattle (Neonatal supplement and Itchy Cow) in Western Canada, vitamin and mineral concentrations tended to be below optimum values, especially in herds provided supplementation free choice. All cows were deficient in vitamin A at calving, averaging 66.27 ± 2.51 ppb, with 50% having nondetectable concentrations. With vitamin E, 8 animals had nondetectable concentrations, only 8 had sufficient concentrations, and those with detectable concentrations averaged 3.16 ppm ± 2.17. Cows had sufficient iron ug/mL averaging 2.14 ± 1.02 and selenium ug/mL 0.09 ± 0.02. As Cheryl Waldner et al. (2023) reported, 24 to 43% copper deficiency is prevalent in cattle in the southern halves of the three prairie provinces. Armed with this information, this study is the first step in developing a systems approach to year-round management of the cow herd’s vitamin and mineral supplementation.

Decision Regret and Vaccine Hesitancy among Nursing Students and Registered Nurses in Italy: Insights from Structural Equation Modeling.

This study focused on vaccine hesitancy and decision regret about the COVID-19 vaccine among nursing students (BScN and MScN) and Registered Nurses (RNs) in Italy. The primary aim was to describe decision regret and vaccine hesitancy among these groups and to understand what influences vaccine hesitancy. Data were collected through an e-survey conducted from March to June 2024. The Decision Regret Scale and the Adult Vaccine Hesitancy Scale were employed to assess regret and hesitancy levels, assessing trust, concerns, and compliance regarding vaccination. Among the participants, 8.64% were not vaccinated. The results indicated moderate to high levels of decision regret and diverse levels of trust, concerns, and compliance with COVID-19 vaccination. Structural equation modeling revealed that decision regret significantly predicted Trust (R2 = 31.3%) and Concerns (R2 = 26.9%), with lower regret associated with higher trust and lower concerns about vaccine safety. The number of COVID-19 vaccine boosters was a significant predictor of Trust and Concerns, with more boosters associated with higher trust and lower concerns. MScN students exhibited higher Compliance compared to RNs (R2 = 2.9%), highlighting the role of advanced education. These findings suggest that addressing decision regret and providing comprehensive vaccine information could enhance trust and compliance.

False-Positive Human Immunodeficiency Virus-1 Test Results With Rapid Seroreversion After Third-Trimester Tdap Booster Vaccination.

False-positive and false-negative results in human immunodeficiency virus (HIV) testing are expected at some frequency. False-positive results have been reported in association with various conditions, including pregnancy, autoimmune disease, and infection. We present an atypical case of a pregnant patient receiving false-positive HIV results for both screening and antibody confirmatory tests after a recent routine vaccination. A 34-year-old woman, G4P1021, with a negative first-trimester HIV test result received a tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) booster at 35 2/7 weeks of gestation. Test results at 36 2/7 weeks of gestation were positive in both HIV-1/2 antigen-antibody screening and a confirmatory HIV-1 antibody differentiation immunoassay, but follow-up test results at 36 5/7 weeks and later were negative. Repeat testing and erythrocyte typing confirmed that this was not a result of laboratory error or specimen mishandling. HIV antiretroviral therapy was started and was later discontinued. A scheduled primary cesarean delivery performed at 39 1/7 weeks of gestation due to breech presentation was uncomplicated. False-positive results in HIV screen and confirmation testing were associated with receipt of a Tdap vaccine booster 7 days prior. This test result pattern is similar to that seen very rarely in previous cases, and the rapid seroreversion to negative suggests an acute immunologic trigger leading to a falsely reactive antibody. Clinicians should be aware of the potential for false-positive HIV test results in patients who recently received vaccination or with other immune triggers and retest at a short interval if suspected.

Kinetics of humoral and cellular immune responses 5 months post-COVID-19 booster dose by immune response groups at the peak immunity phase: An observational historical cohort study using the Fukushima vaccination community survey

BackgroundUnderstanding the waning of immunity after booster vaccinations is important to identify which immune-low populations should be prioritized. MethodsWe investigated longitudinal cellular and humoral immunity after the third vaccine dose in both high- and low-cellular and humoral immunity groups at the peak immunity phase after the booster vaccination in a large community-based cohort. Blood samples were collected from 1045 participants at peak (T1: median 54 days post-third dose) and decay (T2: median 145 days post-third dose) phases to assess IgG(S), neutralizing activity, and ELISpot responses. Participants were categorized into high/low ELISpot/IgG(S) groups at T1. Cellular and humoral responses were tracked for approximately five months after the third vaccination. ResultsIn total, 983 participants were included in the cohort. IgG(S) geometric mean fold change between timepoints revealed greater waning in the >79 years age group (T2/T1 fold change: 0.27) and higher IgG(S) fold change in the low-ELISpot group at T1 (T2/T1 fold change: 0.32–0.33) than in the other groups, although ELISpot geometric mean remained stable. ConclusionsAntibody level of those who did not respond well to third dose vaccination waned rapidly than those who responded well. Evidence-based vaccine strategies are essential in preventing potential health issues caused by vaccines, including side-effects.

Planning and adjusting the COVID-19 booster vaccination campaign to reduce disease burden

As public health policies shifted in 2023 from emergency response to long-term COVID-19 disease management, immunization programs started to face the challenge of formulating routine booster campaigns in a still highly uncertain seasonal behavior of the COVID-19 epidemic. Mathematical models assessing past booster campaigns and integrating knowledge on waning of immunity can help better inform current and future vaccination programs. Focusing on the first booster campaign in the 2021/2022 winter in France, we used a multi-strain age-stratified transmission model to assess the effectiveness of the observed booster vaccination in controlling the succession of Delta, Omicron BA.1 and BA.2 waves. We explored counterfactual scenarios altering the eligibility criteria and inter-dose delay. Our study showed that the success of the immunization program in curtailing the Omicron BA.1 and BA.2 waves was largely dependent on the inclusion of adults among the eligible groups, and was highly sensitive to the inter-dose delay, which was changed over time. Shortening or prolonging this delay, even by only one month, would have required substantial social distancing interventions to curtail the hospitalization peak. Also, the time window for adjusting the delay was very short. Our findings highlight the importance of readiness and adaptation in the formulation of routine booster campaign in the current level of epidemiological uncertainty.

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

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

Use of Haemophilus influenzae Type b-Containing Vaccines Among American Indian and Alaska Native Infants: Updated Recommendations of the Advisory Committee on Immunization Practices - United States, 2024.

Invasive Haemophilus influenzae type b (Hib) disease is a serious bacterial infection that disproportionally affects American Indian and Alaska Native (AI/AN) populations. Hib vaccination with a monovalent Hib conjugate vaccine consisting of Hib capsular polysaccharide (polyribosylribitol phosphate [PRP]) conjugated to outer membrane protein complex of Neisseria meningitidis serogroup B, PRP-OMP (PedvaxHIB, Merck and Co., Inc.) has historically been preferred for AI/AN infants, who are at increased risk for invasive Hib disease, because it provides substantial protection after the first dose. On June 26, 2024, CDC's Advisory Committee on Immunization Practices (ACIP) recommended that a hexavalent, combined diphtheria and tetanus toxoids and acellular pertussis (DTaP), inactivated poliovirus (IPV), Hib conjugate, and hepatitis B (HepB) vaccine, DTaP-IPV-Hib-HepB (Vaxelis, MSP Vaccine Company) should be included with monovalent PRP-OMP in the preferential recommendation for AI/AN infants because of the PRP-OMP Hib component. A primary Hib vaccination series consisting of either 1) monovalent PRP-OMP (2-dose series at ages 2 and 4 months) or 2) DTaP-IPV-Hib-HepB (3-dose series at ages 2, 4, and 6 months) is preferred for AI/AN infants. DTaP-IPV-Hib-HepB is only indicated for use in infants at ages 2, 4, and 6 months and should not be used for the booster doses of Hib, DTaP, or IPV vaccines. For the booster dose of Hib vaccine, no vaccine formulation is preferred for AI/AN children; any Hib vaccine (except DTaP-IPV-Hib-HepB) should be used. This report summarizes evidence considered for these recommendations and provides clinical guidance for the use of Hib-containing vaccines among AI/AN infants and children.

Omicron COVID-19 immune correlates analysis of a third dose of mRNA-1273 in the COVE trial

In the phase 3 Coronavirus Efficacy (COVE) trial (NCT04470427), post-dose two Ancestral Spike-specific binding (bAb) and neutralizing (nAb) antibodies were shown to be correlates of risk (CoR) and of protection against Ancestral-lineage COVID-19 in SARS-CoV-2 naive participants. In the SARS-CoV-2 Omicron era, Omicron subvariants with varying degrees of immune escape now dominate, seropositivity rates are high, and booster doses are administered, raising questions on whether and how these developments affect the bAb and nAb correlates. To address these questions, we assess post-boost BA.1 Spike-specific bAbs and nAbs as CoRs and as correlates of booster efficacy in COVE. For naive individuals, bAbs and nAbs inversely correlate with Omicron COVID-19: hazard ratios (HR) per 10-fold marker increase (95% confidence interval) are 0.16 (0.03, 0.79) and 0.31 (0.10, 0.96), respectively. In non-naive individuals the analogous results are similar: 0.15 (0.04, 0.63) and 0.28 (0.07, 1.08). For naive individuals, three vs two-dose booster efficacy correlates with predicted nAb titer at exposure, with estimates -8% (-126%, 48%), 50% (25%, 67%), and 74% (49%, 87%), at 56, 251, and 891 Arbitrary Units/ml. These results support the continued use of antibody as a surrogate endpoint.

Hepatitis a vaccine immunogenicity and boostability in adults receiving immunosuppressive therapy and adults living with HIV: a prospective single-Centre cohort study.

Hepatitis A (hepA) vaccination is highly immunogenic in healthy individuals, however there is uncertainty about the immunogenicity in immunocompromised populations (ICPs). In this prospective cohort study, people living with HIV (PLWH), patients on immunosuppressive mono- and combination therapy, and controls received two hepA vaccine doses at months 0 and 6-12, or three combined hepA/B vaccine doses at months 0, 1 and 6-12. Antibody levels were measured before and at different time-points post-vaccination (T2, 6, 8, 12months). The primary endpoint was the seroconversion rate (SCR) at T8, defined as hepA antibodies ≥20 mIU/ml. To assess boostability, an additional vaccine dose was administered 1-5years after T12 in those with antibodies < 50 mIU/ml, with antibody measurements before and seven days after the booster dose. We included 150 participants. At T2 SCRs ranged between 35-58% in ICPs versus 94% in controls. Among PLWH, patients on monotherapy, combination therapy and controls SCRs at T8 were 33/34 (97%), 32/34 (94%), 25/30 (83%) and 28/28 (100%) respectively. The booster dose resulted in 71% additional seroconversion (17/24), with only patients using combination therapy not responding. HepA vaccination is highly immunogenic in virologically suppressed PLWH and patients on immunosuppressive monotherapy, with SCRs after the complete hepA vaccination schedule similar to controls and adequate booster responses in case of waning immunity. However, patients using immunosuppressive combination therapy as well as all ICPs who did not receive the complete hepA vaccination schedule, are at risk of non-response to vaccination and post-vaccination antibody measurements are recommended.

A Preliminary Study to Evaluate the Immune Response to a Booster Dose of the Adult Tetanus-Diphtheria Vaccine (Td) Available in Iran

A Preliminary Study to Evaluate the Immune Response to a Booster Dose of the Adult Tetanus-Diphtheria Vaccine (Td) Available in Iran

Neutralizing Antibodies against 10 SARS-CoV-2 Variants at Two Years Post-COVISHIELD Vaccination with Special Reference to Omicron Subvariants and Booster Administration.

To study the durability of neutralizing antibodies (NAbs) against ten SARS-CoV-2 variants among COVISHIELD vaccine recipients from Pune, India, 184 vaccinee samples with (pre-positives) or without (pre-negatives) prior antibody positivity were evaluated. To estimate NAb levels, a validated ten-plex MSD ACE2 neutralization assay was used. NAbs against Alpha, Beta, Delta, and Omicron/subvariants were assessed at 1 month (PD2-1) and 6 months (PD2-6) post-vaccination, post-booster dose, and 2 years (2Y) post-vaccination. In pre-negatives, the seropositivity declined from PD2-1 to PD2-6 for all variants (Omicron variants: 14-54% to 0%; non-Omicron variants: 66-100% to 8-44%). In pre-positives, the decline in seropositivity from PD2-1 to PD2-6 was seen only for Omicron variants (14-39%). At PD2-6, a significant reduction in NAb levels was observed in all vaccinees against all the variants. Irrespective of prior exposure, the diminished anti-variant antibody levels at PD2-6 increased significantly following the administration of the booster. In conclusion, the COVISHIELD vaccine booster dose did provide cross-neutralizing antibodies against broad-range SARS-CoV-2 variants with improved durability up to [16 (15-18)] months post-booster dose and two years post-vaccination.

Risk of Relapse After COVID-19 Vaccination Among Patients With Multiple Sclerosis in France: A Self-Controlled Case Series.

People with multiple sclerosis (MS) have an increased risk of severe coronavirus infection due to their level of motor disability or exposure to certain immunosuppressive treatments. Thus, patients with MS have had priority access to coronavirus disease 2019 (COVID-19) vaccination. However, relapses after vaccination have been reported, leading some patients to not seek the recommended booster doses. The main objective was to estimate the risk of severe relapse after 1, 2, and 3 (booster) doses of COVID-19 vaccination in patients with MS. The secondary objectives were to assess the risk of relapse in clinically meaningful subgroups according to the type of vaccine, the characteristics of the patients, and the use of disease-modifying treatments (DMTs). We conducted a nationwide study using data from the French National Health Data System. Patients with MS were identified according to ICD codes, specific treatments, and reimbursement data up to March 31, 2022. Relapses requiring treatment with high-dose corticosteroids were identified. A self-controlled case series method was used to evaluate the risk of relapse associated with COVID-19 vaccines in the 45 days after vaccination. The associated risk was evaluated after 1, 2, or 3 (booster) doses and is expressed as overall incidence rate ratios (IRRs) and in subgroups of interest. Overall, 124,545 patients with MS were identified on January 1, 2021, and 82% received at least 1 dose of a COVID-19 vaccine (n = 102,524) until December 31, 2021, for a total of 259,880 doses. The combined IRR for MS relapse was 0.97 (0.91-1.03, p = 0.30). The same absence of risk was confirmed in various subgroups (age younger than 50 years, duration of MS < 10 years, use of DMT). A small increase in the relapse risk cannot be excluded after a booster dose (IRR 1.39 [1.08-1.80]) for patients with high MS activity, especially when not treated. There is no increased risk of relapse requiring corticosteroid therapy after COVID-19 vaccination for almost all patients. We cannot exclude an increased risk after the booster dose for patients who have had at least 2 relapses in the previous 2 years. This study provides Class III evidence that COVID-19 vaccination does not increase the risk of severe relapse in patients with MS.

Current vaccination strategy against Piscirickettsia salmonis in Chile based only on the EM-90 genogroup shows incomplete cross-protection for the LF-89 genogroup

Piscirickettsia salmonis, the primary bacterial disease in Chilean salmon farming, necessitates a constant refinement of control strategies. This study hypothesized that the current vaccination strategy for SRS control in the Chilean Atlantic salmon aquaculture industry, which has been in place since 2017 (ALPHA JECT® 5.1 plus LiVac®), solely relies on vaccines formulated with the EM-90 genogroup of P. salmonis (PS-EM-90), triggering a partial cross-immunity response in fish infected with the LF-89 genogroup (PS-LF-89). Relative Percent Survival (RPS) and cell-mediated immune (CMI) response were evaluated in Atlantic salmon post-smolts vaccinated with the standard vaccination strategy but challenged with both PS-EM-90 and PS-LF-89, in addition to other vaccination strategies considering primo vaccination and booster with other commercial vaccines and the possible enhancing effects of the combination with a natural immunomodulator (PAQ-Xtract®) administered orally. The intraperitoneal (I.P.) challenge was performed after 2395°-days (DD) after the start of the immunostimulant delivery, 1905 DD after the primo vaccination, and 1455 DD after the booster vaccination. Unvaccinated fish showed 73.6 and 41.7 % mortality when challenged with PS-EM-90 and PS-LF-89, respectively. Fish infected with PS-LF-89 died significantly faster (21 days post-infection, dpi) than fish challenged with PS-EM-90 (28 dpi) (p = 0.0043) and had a higher probability of death (0.4626) than fish challenged with PS-EM-90. RPS had a significant positive correlation with the PS-EM-90 load of the P. salmonis genogroup (r = 0.540, p < 0.01) but not with the PS-LF-89 load (r = 0.155, p > 0.05). This demonstrated that the immunization strategies were more effective in lowering PS-EM-90 loads, resulting in higher survival rates in fish challenged with PS-EM-90. The current industry vaccination strategy recorded a 100 % RPS when fish were challenged with PS-EM-90, but the RPS dropped significantly to 77 % when fish were challenged with PS-LF-89, meaning that the strategy did not show complete cross-protection. But after adding PAQ-Xtract®, the RPS improved from 77 % to 92 % in fish that were vaccinated with the standard method but then challenged with PS-LF-89. The most effective vaccination strategy was based on LiVac® as primo vaccination and ALPHA JECT® 5.1 plus LiVac® as booster vaccination, with or without PAQ-Xtract®, in both PS-EM-90 (100 %) and PS-LF-89 (96 %) challenged fish. The serum concentration of anti-P. salmonis IgM did not show a correlation with the protection of immunization strategies expressed in survival. Low serum IL-12 and high serum IFNγ concentrations showed a correlation with higher bacterial loads and lower survival. Aggregate analysis showed a significant correlation between higher numbers of CD8+ cells in the head-kidney, higher fish survival, and a lower bacterial load. The immunization strategies were safe for fish and induced only mild microscopic lesions in the gut. Taken together, our results help to better understand the biological interaction between P. salmonis and post-smolt vaccinated Atlantic salmon to deepen the knowledge on vaccine-induced protection, CMI immune response, and cross-immunity applied to improve the current immunization strategy for SRS control in the Chilean salmon industry.

SARS-CoV-2 booster vaccination does not worsen glycemia in people with type 1 diabetes using insulin pumps: an observational study.

Despite an increased risk for adverse outcomes from SARS-CoV-2 infection among individuals with type 1 diabetes (T1D), vaccine hesitancy persists due to safety concerns including dysglycemia. The impact of booster vaccination on individuals using automated insulin delivery (AID) systems remains unclear. We used continuous glucose monitoring (CGM) data from 53 individuals with T1D using insulin pump therapy who received their third and/or fourth COVID-19 vaccination. CGM data from the 14 days before and 3 and 7 days after each vaccination were compared. The primary outcome was glucose time in range (TIR) (70-180mg/dL) 3 and 7 days post-vaccination compared with the 14 days prior. Secondary outcomes included other CGM metrics such as time below range (< 70mg/dL), time above range (> 180mg/dL), mean glucose, co-efficient of variation and average total daily insulin. The cohort comprised 53 adults (64% women, 64% AID), totaling 74 vaccination periods (84% Pfizer-BioNTech boosters), mean ± SD age 40.0 ± 15.9 years, duration of diabetes 26.0 ± 15.4 years. There was no significant difference between pre-vaccination TIR (61.0%±18.5) versus 3 (60.5%±22.8) and 7 days post-vaccination (60.2%±21.8; p = 0.79). Level 1 hypoglycemia, time in range 54-69mg/dL, was lower 3 (1.1%±1.7) and 7 days post-vaccination (1.1%±1.6), compared with 14 days pre-vaccination (1.4%±1.4; p = 0.021). The study provides evidence that SARS-CoV-2 booster vaccination does not acutely worsen glycemia in people with T1D receiving insulin pump therapy.

Uptake of COVID-19 vaccinations amongst 3,433,483 children and young people across four nations in the UK

Background and ObjectivesSARS-CoV-2 infection in children and young people (CYP) can lead to life threatening conditions including COVID-19, transmission to more vulnerable individuals, or even long COVID. Vaccination against COVID-19 reduces the chance of infection and transmission of the virus, but vaccine uptake in the UK has been shown to decrease with age. ApproachWe undertook a multistate-model approach to estimate hazard ratios on national cohorts constructed from linked health and administrative data, adjusting for several demographic factors. The models were applied to 3,433,483 CYP aged 5-17 years between 4th August 2021 and 31st May 2022. The results were combined in a random effects meta-analysis. ResultsUptake of the first COVID-19 vaccine in CYP was lower compared to older age groups in the UK, and diminished further with subsequent doses (34%, 20% and 2% for 1st, 2nd, and booster dose respectively). Age of the CYP and vaccination status of the adults in the household were identified as important risk factors. For example, 5-11-year-olds were less likely to receive their first vaccine compared to 16-17-year-olds (adjusted Hazard Ratio [aHR]: 0.10 (95%CI: 0.06-0.19), and CYP in unvaccinated households were less likely to receive their first vaccine compared to partially vaccinated households (aHR: 0.19, 95%CI 0.13-0.29). Conclusions and Implications Our work highlights the need for targeted strategies to increase COVID-19 vaccine acceptance and uptake among CYP, especially considering the influence of parental consent and household factors. Further research could help identify risk factors in household types to investigate more direct associations, which may be influenced by factors such as living with vulnerable people, familial structure, or deprivation.

Identifying Population Segments by Differing Levels of COVID-19 Vaccine Confidence and Evaluating Subsequent Uptake of COVID-19 Prevention Behaviors: Web-Based, Longitudinal, Probability-Based Panel Survey.

The COVID-19 pandemic prompted the launch of the US Department of Health and Human Services' COVID-19 Public Education Campaign to boost vaccine confidence and uptake among adults, as vaccines are key to preventing severe illness and death. Past segmentation research relevant to COVID-19 behavior has found important differences in attitudes, sociodemographics, and subsequent COVID-19 prevention behaviors across population segments. This study extends prior work by incorporating a more comprehensive set of attitudes, behaviors, and sociodemographic variables to identify population segments by differing levels of COVID-19 vaccine confidence and evaluate differences in their subsequent uptake of COVID-19 prevention behaviors. Data were obtained from 5 waves (January 2021 to June 2022) of a web-based longitudinal, probability-based panel survey of US adults (N=4398) administered in English and in Spanish. Participants were recruited from NORC at the University of Chicago's national AmeriSpeak panel and were invited to participate across multiple waves. Latent class cluster analysis estimated segments of respondents based on over 40 COVID-19 attitudes, beliefs, behaviors, and sociodemographics as reported in wave 1. Survey-weighted cross-tabulations and bivariate regression analyses assessed differences in COVID-19 vaccine uptake, booster uptake, mask use, and social distancing in all segments across all 5 survey waves. A total of 6 segments (hardline nonintenders, prevention-compliant nonintenders, burned-out waiters, anxious waiters, skeptical confidents, and ready confidents) were identified, which differed by their COVID-19 vaccine confidence, prevention-related attitudes and behaviors, and sociodemographics. Cross-tabulations and regression results indicated significant segment membership differences in COVID-19 vaccine and booster timing, mask use, and social distancing. Results from survey-weighted cross-tabulations comparing COVID-19 vaccine and booster uptake across segments indicate statistically significant differences in these outcomes across the 6 segments (P<.001). Results were statistically significant for each segment (P<.01 for booster uptake among burned-out waiters; P<.001 for all other coefficients), indicating that, on average, respondents in segments with lower intentions to vaccinate reported later receipt of COVID-19 vaccines and boosters relative to the timing of vaccine and booster uptake among ready confidents. Results extend previous research by showing that initial beliefs and behaviors relevant to COVID-19 vaccination, mask use, and social distancing are important for understanding differences in subsequent compliance with recommended COVID-19 prevention measures. Specifically, we found that across respondent segments, the probability of vaccine and booster uptake corresponded with both COVID-19 vaccine confidence and mask use and social distancing compliance; more compliant segments were more likely to get vaccinated or boosted than less compliant segments given similar levels of vaccine confidence. These findings help identify appropriate audiences for campaigns. Results highlight the use of a comprehensive list of attitudes, behaviors, and other individual-level characteristics that can serve as a basis for future segmentation efforts relevant to COVID-19 and other infectious diseases.

Recurrent SARS-CoV-2 spike mutations confer growth advantages to select JN.1 sublineages

ABSTRACT The recently dominant SARS-CoV-2 Omicron JN.1 has evolved into multiple sublineages, with recurrent spike mutations R346T, F456L, and T572I, some of which exhibit growth advantages, such as KP.2 and KP.3. We investigated these mutations in JN.1, examining their individual and combined effects on immune evasion, ACE2 receptor affinity, and in vitro infectivity. F456L increased resistance to neutralization by human sera, including those after JN.1 breakthrough infections, and by RBD class-1 monoclonal antibodies, significantly altering JN.1 antigenicity. R346T enhanced ACE2-binding affinity and modestly boosted the infectivity of JN.1 pseudovirus, without a discernible effect on serum neutralization, while T572I slightly bolstered evasion of SD1-directed mAbs against JN.1's ancestor, BA.2, possibly by altering SD1 conformation. Importantly, expanding sublineages such as KP.2 containing R346T, F456L, and V1104L, showed similar neutralization resistance as JN.1 with R346T and F456L, suggesting V1104L does not appreciably affect antibody evasion. Furthermore, the hallmark mutation Q493E in KP.3 significantly reduced ACE2-binding affinity and viral infectivity, without noticeably impacting serum neutralization. Our findings illustrate how certain JN.1 mutations confer growth advantages in the population and could inform the design of the next COVID-19 vaccine booster.