Vaccine Safety Research Articles

Delivery and Safety of a Two-Dose Preventive Ebola Virus Disease Vaccine in Pregnant and Non-Pregnant Participants during an Outbreak in the Democratic Republic of the Congo

Delivery and Safety of a Two-Dose Preventive Ebola Virus Disease Vaccine in Pregnant and Non-Pregnant Participants during an Outbreak in the Democratic Republic of the Congo

Medical occurrence and safety of SARS-CoV-2 vaccination outside of the hospital setting.

During COVID-19 pandemic, vaccination has been strongly recommended and advocated to prevent COVID-19 infection and adverse outcomes, particularly among at-risk populations. The vaccination against SARS-CoV-2 (COVAC) occurred at off-site locations capable of accommodating large crowds, distinct from the hospital setting, where a team of intensivists, emergency physicians, and nurses, ensuring prompt medical attention (medical occurrences, MO) in cases of adverse event following immunization. Our aims were to estimate the incidence of MO, and to assess its association with demographics, and vaccine characteristics. Our retrospective cohort study included all subject aged 12years and older who received vaccinations at two large out-of-hospital vaccination hubs (Fiera Milano City, Palazzo delle Scintille), between April 12th and August 31st, 2021. Nine hundred and ninety-five thousand and twenty-eight vaccinations were administrated. MOs incidence rate was 278/100,000 doses (95% confidence interval (CI) 268-289). Most MOs were mild (86.27%) and mainly observed in subjects who received the Comirnaty vaccine; 92 MOs (3.32%) were severe and mostly occurred in recipients of the Vaxzeria vaccine. The incidence rate for hospital transfers following vaccination was 4.7/100,000 doses (95% CI 3.5-6.2) and any level of anaphylaxis occurred in 0.4 cases per 100,000 administrated doses (95% CI 0.3.-0.7). Sex, age, type of vaccine and first dose were associated with incidence of MO. Our results showed a low incidence rate in MOs after COVAC, mainly mild and support the feasibility, effectiveness and safety of vaccinations administered in hubs with a dedicated SEU located outside of the hospital setting.

Closing the gaps in adolescent vaccinations: Rhode Island’s Vaccinate Before You Graduate program as a model for other jurisdictions

ObjectiveThe northeastern state of Rhode Island (RI) has a Vaccinate Before You Graduate (VBYG) program that supplements the traditional primary care infrastructure by providing vaccines to adolescents while they are in school, with no out-of-pocket expenses. We analyzed data from RI’s immunization registry to evaluate whether VBYG also reduces disparities in adolescent immunization rates. MethodsWe identified adolescent and catch-up vaccines administered in RI to people who were aged 11–18 at any point during the 5-year study period of 2019–2023, and conducted bivariate and multivariate analyses of vaccine administration data by setting (VBYG clinics, community health centers [CHCs], all other primary care practices [oPCPs], other school-based clinics, and other sites) and adolescent demographics (racial and ethnic identity, insurance status, sex, and age at time of vaccine) ResultsOf over 387,000 routine vaccines administered during the study period, 3.3 % were administered by a VBYG clinic despite significant declines during school closures associated with the early COVID-19 pandemic. VBYG-administered doses went to slightly older youth, and a higher proportion were catch-up doses (25.7 % versus 14.1 % for CHC doses and 6.5 % for oPCP). Youths received an average of 2.71 vaccines in VBYG clinics compared to 1.77 from oPCPs and 2.08 from CHCs. A higher proportion of vaccines administered by VBYG went to adolescents of color and those without private insurance than those administered by oPCPs. ConclusionsVBYG provides a model to other jurisdictions of a vaccine safety net for adolescents who may not otherwise receive recommended vaccines before exiting the school system.

Safety and efficacy assessment of an mRNA rabies vaccine in dogs, rodents, and cynomolgus macaques

Rabies is a lethal disease caused by the rabies virus (RABV), which causes acute neurological infections in mammals, including human beings. We previously reported that an mRNA vaccine (LVRNA001) encoding the rabies virus’s glycoprotein induced strong protective immune responses to rabies in mice and dogs. Here, we further evaluate the safety of LVRNA001. First, we performed a confirmative efficacy study in dogs, which showed that LVRNA001 fully protected the animals from the virus, both pre- and post-infection. Moreover, using pre- and post-exposure prophylaxis murine models, we showed that LVRNA001, built from the CTN-1 strain, was able to protect against various representative RABV strains from the China I–VII clades. To evaluate the safety of the vaccine, chronic and reproductive toxicity studies were performed with cynomolgus macaques and rats, respectively. In a repeated-dose chronic toxicity study, vaccinated monkeys displayed no significant alterations in body weight, temperature, or hematological and biochemical markers. Lymphocyte subset measurement and histopathological examination showed that no toxicity was associated with the vaccine. The immunogenicity study in cynomolgus macaques demonstrated that LVRNA001 promoted the generation of neutralizing antibodies and Th1-biased immune response. Evaluation of reproductive toxicity in rats revealed that administration of LVRNA001 had no significant effects on fertility, maternal performance, reproductive processes, and postnatal outcomes. In conclusion, LVRNA001 can provide efficient protection against rabies virus infection in dogs and mice, and toxicity studies showed no significant vaccine-related adverse effects, suggesting that LVRNA001 is a promising and safe vaccine candidate for rabies prophylaxis and therapy.

A scoping review of global COVID-19 vaccine hesitancy among pregnant persons

Uptake of the COVID-19 vaccine among pregnant persons is lower than the general population. This scoping review explored pregnant people’s attitudes towards the COVID-19 vaccine, reasons for vaccine hesitancy, and whether attitudes about COVID-19 vaccines differ by country of origin. A scoping review was conducted across PubMed, Embase, CINHAL, and Scopus. Inclusion criteria were articles published in English from 2019–2022 focused on attitudes towards COVID-19 vaccination among pregnant persons. Data analysis was done via the 5Cs framework for vaccine hesitancy: Constraints, Complacency, Calculation, Confidence, and Collective Responsibility. 44 articles were extracted. A lack of confidence in vaccine safety was the most prevalent theme of hesitancy among pregnant persons. This was largely driven by a lack of access to information about the vaccine as well as mistrust of the vaccine and medical professionals. Meanwhile, vaccine acceptance was mostly driven by a desire to protect themselves and their loved ones. Overall, COVID-19 vaccine hesitancy among pregnant persons continues to be high. Vaccine hesitancy is primarily driven by fear of the unknown side effects of the vaccine on pregnant persons and their fetuses along with a lack of information and medical mistrust. Some differences can be seen between high income and low- and middle-income countries regarding vaccine hesitancy, showing that a single solution cannot be applied to all who are vaccine hesitant. General strategies, however, can be utilized to reduce vaccine hesitancy, including advocating for inclusion of pregnant persons in clinical trials and incorporating consistent COVID-19 vaccine counseling during prenatal appointments.

Safety and effectiveness of a recombinant hepatitis E vaccine in women of childbearing age in rural Bangladesh: a phase 4, double-blind, cluster-randomised, controlled trial

Hepatitis E virus (HEV) leads to high mortality in pregnant women in low-income countries. We aimed to evaluate the safety of a HEV vaccine and its effectiveness in preventing hepatitis E during pregnancy. In this phase 4, double-blind, cluster-randomised trial, 67 villages in Matlab, Bangladesh, were randomised 1:1 to receive HEV239 (a recombinant HEV vaccine) or a control vaccine (Hepa-B, a hepatitis B vaccine), using block randomisation with random number tables and blocks of size eight, stratified by cluster population size. Eligible non-pregnant women (aged 16-39 years) were vaccinated intramuscularly on day 0, at 1 month, and at 6 months, and followed up for 2 years after the last immunisation. The primary endpoint was hepatitis E in the pregnant, per-protocol population (those who received all three doses within 2 days of the scheduled dates), while safety was a secondary endpoint, assessed in the intention-to-treat (ITT) population (participants who received at least one dose). Solicited adverse events were recorded for the first 7 days after each dose, and unsolicited events until 2 years after a participant's final dose. Pregnancy-related safety outcomes were assessed in the pregnant ITT population. This study is registered with ClinicalTrials.gov (NCT02759991). Between Oct 2, 2017, and Feb 28, 2019, 19 460 participants were enrolled and received either HEV239 (9478 [48·7%] participants, 33 clusters) or Hepa-B (9982 [51·3%] participants, 34 clusters), of whom 17 937 (92·2%) participants received three doses and 17 613 (90·5%) were vaccinated according to protocol (8524 [48·4%] in the HEV239 group and 9089 [51·6%] in the control group). No pregnant participants were confirmed to have hepatitis E in either treatment group. HEV239 showed a mild safety profile, similar to Hepa-B, with no difference in the proportion of solicited adverse events between groups and no severe solicited events. Pain was the most common local symptom (1215 [12·8%] HEV239 recipients and 1218 [12·2%] Hepa-B recipients) and fever the most common systemic symptom (141 [1·5%] HEV239 recipients and 145 [1·5%] Hepa-B recipients). None of the serious adverse events or deaths were vaccine related. Among pregnant participants, the HEV239 group had a higher risk of miscarriage (136 [5·7%] of 2407 pregnant participants) compared with the control group (102 [3·9%] of 2604; adjusted odds ratio 1·54 [95% CI 1·15-2·08]). The effectiveness of HEV239 in pregnant women remains uncertain. HEV239 was safe and well tolerated in non-pregnant women, but findings regarding miscarriage warrant further investigation. Research Council of Norway; Innovax.

Determinants of parental demand of human papillomavirus vaccination for adolescent daughters in China: Contingent valuation survey.

Several types of human papillomavirus (HPV) vaccines have been approved for use in adolescent girls in China. These vaccines are regulated as non-National Immunisation Program vaccines and are optional and generally fully self-paid by vaccinees. To assess parents' demand for HPV vaccination by eliciting their willingness-to-pay for their adolescent daughters to be vaccinated against HPV and to examine the determinants of demand for HPV vaccination in China. A contingent valuation survey was conducted across three cities in Shandong Province in eastern China. We selected 11 junior middle schools with different socioeconomic features and randomly selected 6 classes in each school, and questionnaires were distributed to all girls aged 12-16 in the 66 classes for their parents to complete. A payment card approach was used to elicit parental willingness-to-pay for HPV vaccination for their daughters. We also collected a wide array of socioeconomic and psychological variables and interval regressions were applied to examine the determinants of parental willingness-to-pay. A total of 1074 eligible parents who completed valid questions were included in analyses. Over 85% of parents believed HPV vaccines were, in general, necessary and beneficiary. However, only around 10% believed that their daughters would be infected by HPV. About 8% of parents would not accept HPV vaccine even if the vaccine were free mainly due to concerns about the potential side effects and vaccine safety and quality issues, and 27.37% would only accept the vaccine if it were free. The median willingness-to-pay was 300 CNY (42 USD). Several factors were positively correlated with higher willingness-to-pay: income, urban residence (relative to rural residence), mothers (relative to fathers), parents' beliefs about vaccine benefits, whether they should make decisions for their daughters, and whether their daughters would be susceptible to HPV. Though education-level was not significantly correlated with willingness-to-pay in the main regressions, a subgroup analysis revealed interesting dynamics in the relation between education and willingness-to-pay across different income-levels. There is a large gap between parents' willingness-to-pay and the market price of HPV vaccine for girls in China. Parents generally believed the HPV vaccines were beneficial and necessary but when asked for their daughters, most parents did not believe their daughters would be infected by HPV despite the high prevalence in China. Future focus should be on ensuring the provision of accurate health information about HPV prevalence, vaccine quality, and safety to promote vaccine uptake, and promotional efforts tailored to different income groups might yield better effects. Government involvement in negotiating more widely acceptable and affordable prices or subsidising may be necessary for protecting high-risk population groups.

Safety, Immunogenicity, and Effectiveness of Chinese-Made COVID-19 Vaccines in the Real World: An Interim Report of a Living Systematic Review

Background: Several COVID-19 vaccines were developed and approved in China. Of these, the BIBB-CorV and CoronaVac inactivated whole-virion vaccines were widely distributed in China and developing countries. However, the performance of the two vaccines in the real world has not been summarized. Methods: A living systematic review based on findings from ongoing post-licensure studies was conducted, applying standardized algorithms. Articles published between 1 May 2020 and 31 May 2022 in English and Chinese were searched for in Medline, Embase, WanFang Data, medRxiv, bioRxiv, arXiv, SSRN, and Research Square, using SARS-CoV-2, COVID-19, and vaccine as the MeSH terms. Studies with estimates of safety, immunogenicity, and effectiveness from receiving the BIBB-CorV or CoronaVac vaccine that met the predefined screening criteria underwent a full-text review. The Joanna Briggs Institute’s Critical Appraisal Checklist and the Cochrane risk of bias were used for assessment of the quality. A random-effects meta-regression model was applied to identify the potential impact factors on the vaccines’ effectiveness. Results: In total, 32578 articles were identified, of these, 770 studies underwent a full-text review. Eventually, 213 studies were included. The pooled occurrence of solicited and unsolicited adverse events after any dose of either vaccine varied between 10% and 40%. The top five commonly reported rare adverse events were immunization stress-related responses (211 cases, 50.0%), cutaneous responses (43 cases, 10.2%), acute neurological syndrome (39 cases, 9.2%), anaphylaxis (17 cases, 4.0%), and acute stroke (16 cases, 3.8%). The majority (83.3%) recovered or were relieved within several days. The peak neutralization titers against the ancestral strain was found within 1 month after the completion of the primary series of either vaccine, with a GMT (geometric mean titer) of 43.7 (95% CI: 23.2–82.4), followed by a dramatic decrease within 3 months. At Month 12, the GMT was 4.1 (95% CI: 3.8–4.4). Homologous boosting could restore humoral immunity, while heterologous boosting elicited around sixfold higher neutralization titers in comparison with homologous boosting. The effectiveness of receiving either vaccine against death and severe disease was around 85% for both shortly after the primary series. At Month 12, the protection against death did not decline, while the protection against severe disease decreased to ~75%. Conclusions: Both the BIBP-CorV and CoronaVac inactivated vaccines are safe. Sustained vaccine effectiveness against death was determined 12 months after the primary series, although protection against severe disease decreased slightly over time. A booster dose could strengthen the waning effectiveness; however, the duration of the incremental effectiveness and the additional benefit provided by a heterologous booster need to be studied.

Safety and Efficacy of Antiviral Drugs and Vaccines in Pregnant Women: Insights from Physiologically Based Pharmacokinetic Modeling and Integration of Viral Infection Dynamics

Addressing the complexities of managing viral infections during pregnancy is essential for informed medical decision-making. This comprehensive review delves into the management of key viral infections impacting pregnant women, namely Human Immunodeficiency Virus (HIV), Hepatitis B Virus/Hepatitis C Virus (HBV/HCV), Influenza, Cytomegalovirus (CMV), and SARS-CoV-2 (COVID-19). We evaluate the safety and efficacy profiles of antiviral treatments for each infection, while also exploring innovative avenues such as gene vaccines and their potential in mitigating viral threats during pregnancy. Additionally, the review examines strategies to overcome challenges, encompassing prophylactic and therapeutic vaccine research, regulatory considerations, and safety protocols. Utilizing advanced methodologies, including PBPK modeling, machine learning, artificial intelligence, and causal inference, we can amplify our comprehension and decision-making capabilities in this intricate domain. This narrative review aims to shed light on diverse approaches and ongoing advancements, this review aims to foster progress in antiviral therapy for pregnant women, improving maternal and fetal health outcomes.

Chronological Management of Adjuvant Effect for Optimized mRNA Vaccine Inspired by Natural Virus Infection.

The efficacy and safety of mRNA vaccines both rely on a fine-tuning of specific humoral and cellular immune responses. Instead of adjustments in vaccine component, we proposed a concept of chronological management of adjuvant effect to modulate the adaptive immune potency and preference inspired by natural virus infection. By simulating type I interferon expression dynamics during viral infection, three vaccine strategies employing distinct exposure sequences of adjuvant and mRNA have been developed, namely Precede, Coincide, and Follow. Follow, the strategy of adjuvant administration following mRNA, effectively suppressed tumor progression, which was attributed to enhanced mRNA translation, augmented p-MHC I expression, and elevated CD8+ T cell response. Meanwhile, Follow exhibited improved biosafety, characterized by reduced incidences of cardiac and liver toxicity, owing to its alteration to the vaccination microenvironment between successive injections. Our strategy highlights the importance of fine-tuning adjuvant effect dynamics in optimizing mRNA vaccines for clinical application.

Serial cell culture passaging in vitro led to complete attenuation and changes in the characteristic features of a virulent porcine deltacoronavirus strain.

Porcine deltacoronavirus (PDCoV) is an important enteric coronavirus that has caused enormous economic losses in the pig industry worldwide. However, no commercial vaccine is currently available. Therefore, developing a safe and efficacious live-attenuated vaccine candidate is urgently needed. In this study, the PDCoV strain CH/XJYN/2016 was continuously passaged in LLC-PK cells until passage 240, and the virus growth kinetics in cell culture, pathogenicity in neonatal piglets, transcriptome differences after LLC-PK infection, changes in the functional characteristics of the spike (S) protein in the high- and low-passage strains, genetic variation of the virus genome, resistance to pepsin and acid, and protective effects of this strain when used as a live-attenuated vaccine were examined. The results of animal experiments demonstrated that the virulent PDCoV strain CH/XJYN/2016 was completely attenuated and not pathogenic in piglets following serial cell passage. Genome sequence analysis showed that amino acid mutations in nonstructural proteins were mainly concentrated in Nsp3, structural protein mutations were mainly concentrated in the S protein, and the N, M, and E genes were conserved. Transcriptome comparison revealed that compared with negative control cells, P10-infected LLC-PK cells had the most differentially expressed genes (DEGs), while P0 and P240 had the least number of DEGs. Analysis of trypsin dependence and related structural differences revealed that the P10 S protein interacted more strongly with trypsin and that the P120 S protein interacted more strongly with the APN receptor. Moreover, the infectivity of P240 was not affected by pepsin but was significantly decreased after exposure to low pH. Furthermore, the P240-based live-attenuated vaccine provided complete protection to piglets against the challenge of virulent PDCoV. In conclusion, we showed that a PDCoV strain was completely attenuated through serial passaging in vitro. These results provide insights into the potential molecular mechanisms of PDCoV attenuation and the development of a promising live-attenuated PDCoV vaccine.IMPORTANCEPorcine deltacoronavirus (PDCoV) is one of the most important enteropathogenic pathogens that cause diarrhea in pigs of various ages, especially in suckling piglets, and causes enormous economic losses in the global commercial pork industry. There are currently no effective measures to prevent and control PDCoV. As reported in previous porcine epidemic diarrhea virus (PEDV) and transmissible gastroenteritis virus studies, inactivated vaccines usually elicit less robust protective immune responses than live-attenuated vaccines in native sows. Therefore, identifying potential attenuation mechanisms, gene evolution, pathogenicity differences during PDCoV passaging, and immunogenicity as live-attenuated vaccines is important for elucidating the mechanism of attenuation and developing safe and effective vaccines for virulent PDCoV strains. In this study, we demonstrated that the virulence of the PDCoV strain CH/XJYN/2016 was completely attenuated following serial cell passaging in vitro, and changes in the biological characteristics and protection efficacy of the strain were evaluated. Our results help elucidate the mechanism of PDCoV attenuation and support the development of appropriate designs for the study of live PDCoV vaccines.

HPV vaccine acceptance in Latin America and the Caribbean: a systematic review and meta-analysis

Human Papillomavirus (HPV) infection poses a significant health burden in Latin America and the Caribbean (LAC), leading to various conditions from benign to malignant, including cervical, anal, and oropharyngeal cancers. This systematic review encompassed 24 studies with a total of 14,466 participants, exploring HPV vaccine acceptance in the region. It was conducted using the following databases: PubMed, Scopus, Ovid Medline, and Web of Science. The review reveals an 84% prevalence of HPV vaccine acceptance in the LAC. Factors influencing acceptance include education, income levels, and vaccine safety concerns. Peru and Honduras exhibited the highest acceptance rates, while the coronavirus disease 2019 (COVID-19) pandemic contributed to declining acceptance post-2019. The importance of educational campaigns and healthcare recommendations in promoting vaccine acceptance is highlighted, along with the impact of reduced vaccination access during the pandemic. This study underscores the critical role of ongoing educational initiatives and accessible healthcare in maintaining high HPV vaccine acceptance rates in LAC. Addressing the reduced acceptance during the pandemic is pivotal for reinstating effective vaccination programs. Findings emphasize the need of sustained efforts to ensure widespread vaccine acceptance, thereby mitigating the burden of HPV-related diseases in the region.

Safety and Effectiveness of COVID-19 Vaccines During Pregnancy: A Living Systematic Review and Meta-analysis.

Pregnant persons are susceptible to significant complications following COVID-19, even death. However, worldwide COVID-19 vaccination coverage during pregnancy remains suboptimal. This study assessed the safety and effectiveness of COVID-19 vaccines administered to pregnant persons and shared this evidence via an interactive online website. We followed Cochrane methods to conduct this living systematic review. We included studies assessing the effects of COVID-19 vaccines in pregnant persons. We conducted searches every other week for studies until October 2023, without restrictions on language or publication status, in ten databases, guidelines, preprint servers, and COVID-19 websites. The reference lists of eligible studies were hand searched to identify additional relevant studies. Pairs of review authors independently selected eligible studies using the web-based software COVIDENCE. Data extraction and risk of bias assessment were performed independently by pairs of authors. Disagreements were resolved by consensus. We performed random-effects meta-analyses of adjusted relative effects for relevant confounders of comparative studies and proportional meta-analyses to summarize frequencies from one-sample studies using R statistical software. We present the GRADE certainty of evidence from comparative studies. Findings are available on an interactive living systematic review webpage, including an updated evidence map and real-time meta-analyses customizable by subgroups and filters. We included 177 studies involving 638,791 participants from 41 countries. Among the 11 types of COVID-19 vaccines identified, the most frequently used platforms were mRNA (154 studies), viral vector (51), and inactivated virus vaccines (17). Low to very low-certainty evidence suggests that vaccination may result in minimal to no important differences compared to no vaccination in all assessed maternal and infant safety outcomes from 26 fewer to 17 more events per 1000 pregnant persons, and 13 fewer to 9 more events per 1000 neonates, respectively. We found statistically significant reductions in emergency cesarean deliveries (9%) with mRNA vaccines, and in stillbirth (75-83%) with mRNA/viral vector vaccines. Low to very low-certainty evidence suggests that vaccination during pregnancy with mRNA vaccines may reduce severe cases or hospitalizations in pregnant persons with COVID-19 (72%; 95% confidence interval [CI] 42-86), symptomatic COVID-19 (78%; 95% CI 21-94), and virologically confirmed SARS-CoV-2 infection (82%; 95% CI 39-95). Reductions were lower with other vaccine types and during Omicron variant dominance than Alpha and Delta dominance. Infants also presented with fewer severe cases or hospitalizations due to COVID-19 and laboratory-confirmed SARS-CoV-2 infection (64%; 95% CI 37-80 and 66%; 95% CI 37-81, respectively). We found a large body of evidence supporting the safety and effectiveness of COVID-19 vaccines during pregnancy. While the certainty of evidence is not high, it stands as the most reliable option available, given the current absence of pregnant individuals in clinical trials. Results are shared in near real time in an accessible and interactive format for scientists, decision makers, clinicians, and the general public. This living systematic review highlights the relevance of continuous vaccine safety and effectiveness monitoring, particularly in at-risk populations for COVID-19 impact such as pregnant persons, during the introduction of new vaccines. PROSPERO: CRD42021281290.

Genetic diversity accelerates canine distemper virus adaptation to ferrets.

RNA viruses adapt rapidly to new host environments by generating highly diverse genome sets, so-called "quasispecies." Minor genetic variants promote their rapid adaptation, allowing for the emergence of drug-resistance or immune-escape mutants. Understanding these adaptation processes is highly relevant to assessing the risk of cross-species transmission and the safety and efficacy of vaccines and antivirals. We hypothesized that genetic memory within a viral genome population facilitates rapid adaptation. To test this, we investigated the adaptation of the Morbillivirus canine distemper virus to ferrets and compared an attenuated, Vero cell-adapted virus isolate with its recombinant derivative over consecutive ferret passages. Although both viruses adapted to the new host, the reduced initial genetic diversity of the recombinant virus resulted in delayed disease onset. The non-recombinant virus gradually increased the frequencies of beneficial mutations already present at very low frequencies in the input virus. In contrast, the recombinant virus first evolved de novo mutations to compensate for the initial fitness impairments. Importantly, while both viruses evolved different sets of mutations, most mutations found in the adapted non-recombinant virus were identical to those found in a previous ferret adaptation experiment with the same isolate, indicating that mutations present at low frequency in the original virus stock serve as genetic memory. An arginine residue at position 519 in the carboxy terminus of the nucleoprotein shared by all adapted viruses was found to contribute to pathogenesis in ferrets. Our work illustrates the importance of genetic diversity for adaptation to new environments and identifies regions with functional relevance.IMPORTANCEWhen viruses encounter a new host, they can rapidly adapt to this host and cause disease. How these adaptation processes occur remains understudied. Morbilliviruses have high clinical and veterinary relevance and are attractive model systems to study these adaptation processes. The canine distemper virus is of particular interest, as it exhibits a broader host range than other morbilliviruses and frequently crosses species barriers. Here, we compared the adaptation of an attenuated virus and its recombinant derivative to that of ferrets. Pre-existing mutations present at low frequency allowed faster adaptation of the non-recombinant virus compared to the recombinant virus. We identified a common point mutation in the nucleoprotein that affected the pathogenesis of both viruses. Our study shows that genetic memory facilitates environmental adaptation and that erasing this genetic memory by genetic engineering results in delayed and different adaptation to new environments, providing an important safety aspect for the generation of live-attenuated vaccines.

The Impact of Lebrikizumab on Vaccine-Induced Immune Responses: Results from a Phase3 Study in Adult Patients with Moderate-to-Severe Atopic Dermatitis.

Lebrikizumab, a high-affinity IgG4 monoclonal antibody that selectively inhibits interleukin-13 with high binding affinity and slow dissociation rate, prevents the formation of the interleukin-4Rα/interleukin-13Rα1heterodimer receptor signaling complex. Here we report the impact of lebrikizumab on responses to two non-live vaccines in adult patients with moderate-to-severe atopic dermatitis (AD). ADopt-VA (NCT04626297) was a double-blind, placebo-controlled, parallel-group, 16-week, phase3 randomized study to assess the impact of lebrikizumab treatment on non-live vaccine immune responses, and efficacy and safety of lebrikizumab compared with placebo. Eligible patients included adults from 18 to 55years of age with moderate-to-severe chronic AD who were randomly assigned 1:1 to lebrikizumab 250mg every 2weeks or placebo and stratified according to disease severity. The primary endpoints were the development of a booster response to tetanus toxoid and a positive antibody response to meningococcal conjugate vaccine (MCV), 4weeks after administration of the corresponding vaccine. At week16, 73.6% of patients in the lebrikizumab group (n = 78/106) achieved Tdap booster response compared with 73.4% of patients in the placebo group (n = 58/79). MCV vaccine response was observed in 86.9% of patients in the lebrikizumab group (n = 86/99) and 75.0% of patients in the placebo group (n = 60/80). At week16, IGA0,1 with ≥ 2-point improvement from baseline was achieved by 40.6% (n = 51/125) of patients treated with lebrikizumab and 18.9% (n = 23/122) of patients who received placebo (p < 0.001). There was a higher proportion of patients achieving EASI75 at week16 in the lebrikizumab-treated patients (58.0%, n = 72/125) compared with placebo (32.7%, n = 40/122, p < 0.001). Treatment with lebrikizumab did not impact response to non-live vaccines Tdap and MCV in this study. Lebrikizumab treatment had a significant degree of efficacy compared to placebo across multiple endpoints. ClinicalTrials.gov identifier NCT04626297.

COVID-19 mRNA vaccination responses in individuals with sickle cell disease: an ASH RC Sickle Cell Research Network Study

AbstractChildren and adults with sickle cell disease (SCD) have increases in morbidity and mortality with COVID-19 infections. The American Society of Hematology Research Collaborative Sickle Cell Disease Research Network performed a prospective COVID-19 vaccine study to assess antibody responses and analyze whether messenger RNA (mRNA) vaccination precipitated any adverse effects unique to individuals with SCD. Forty-one participants received 2 doses of the Pfizer-BioNTech vaccine and provided baseline blood samples before vaccination and 2 months after the initial vaccination for analysis of immunoglobulin G (IgG) reactivity against the receptor binding domain (RBD) of the severe acute respiratory syndrome coronavirus 2 spike protein. Six-month IgG reactivity against the viral RBD was also available in 37 patients. Postvaccination reactogenicity was common and similar to the general population. There were no fevers that required inpatient admission. Vaso-occlusive pain within 2 to 3 days of first or second vaccination was reported by 5 participants (12%) including 4 (10%) who sought medical care. Twenty-seven participants (66%) were seropositive at baseline, and all 14 initially seronegative participants (34%) converted to seropositive after vaccination. Overall, mRNA vaccination had a good risk-benefit profile in individuals with SCD. This mRNA vaccine study also marks the first evaluation of vaccine safety and antibody response in very young children with SCD. This trial was registered at www.ClinicalTrials.gov as #NCT05139992.

COVID-19 severity, breakthrough infections and vaccine safety in young individuals with autoimmune diseases: insights from the COVAD study.

Notwithstanding the wealth of literature on COVID-19, studies focusing on young adults with autoimmune diseases (AD) are lacking. To determine early (within 7days) and late (after 7days) anti-SARS-CoV-2 vaccine-related adverse events (AEs), post-vaccine disease flares, COVID-19 severity and breakthrough infections (B-INFs) in young people with rheumatic diseases (RMDs) and non-rheumatic autoimmune diseases (nr-ADs) compared to healthy controls (HC). Data were captured through the international COVID-19 vaccination in autoimmune diseases (COVAD) 1 and 2 questionnaires. Of 20,685 complete responses, we identified 6010 from patients aged 18-35years (1692 RMD, 400 nrADs, 3918 HC) who received up to 4 vaccine doses. BNT162b2 was the most frequently administered vaccine and prior to vaccination, 7% of people with nrAD were taking immunosuppressants (IS) versus 80% in RMDs. Early mild AEs were more frequent in RMDs (93%) and nr-ADs (92%) compared to HC (85%). The frequency of late mild AEs was < 20% in all groups. Severe AEs were rare. SARS-CoV-2 infection rates were similar across all groups, however, RMD patients reported a single episode of infection more frequently than nrADs and HC, while nrADs reported multiple infections more frequently than RMD. Self-reported disease flares were reported by 10% or RMD and 7% of nrAD patients. Our study reinforces the safety of anti-SARS-CoV-2 vaccine also in young people with ADs, but it also highlights that among young individuals the number and clinical picture of SARS-CoV-2 infections is affected more by the type of AD rather than by coexisting IS therapy.

Evaluating Factors That Influence Influenza Vaccination Uptake among Pregnant People in a Medically Underserved Area in Washington State

Introduction: Despite substantial evidence demonstrating the effectiveness of influenza vaccines, only 38.6% of the adult United States population received an influenza vaccine during the 2023–2024 flu season. Vaccination rates are typically lower among U.S. minority groups, and in 2022, pregnant persons from U.S. minority racial and ethnic groups showed a decrease in influenza vaccine coverage. Methods: A survey was conducted with residents of Yakima County, Washington, which is home to one of the state’s largest percentages of people who identify as Hispanic or Latino/a. The objective was to evaluate the uptake of influenza vaccine among pregnant persons. Surveys were sent to a random sample of 3000 residential mailing addresses. Of the 500 respondents, 244 (52.1%) reported that they had been pregnant, with those identifying as Hispanic or Latino/a constituting 23.8% of this total. Only 62 (26.2%) reported being immunized against influenza during pregnancy. Respondents who were immunized against influenza chose to be vaccinated to protect themselves from the flu (85.5%, n = 53); because a healthcare provider recommended getting vaccinated (85.5%, n = 53); to protect the baby from the flu (82.3%, n = 51); because it was available for free or low cost (62.9%, n = 39); and because vaccination was convenient (54.8%, n = 34). Qualitative evaluation identified that participants who were not vaccinated against influenza during pregnancy believed the vaccination was not needed, was not recommended by a healthcare provider, was difficult to access, they were against vaccination in general, or they were concerned about the safety and ingredients of the vaccine. Conclusion: Barriers to vaccination identified in this study included vaccine distrust, lack of awareness, and concerns about vaccine efficacy and safety. Healthcare providers can help address these concerns by providing education and recommendations about the importance of influenza vaccination during pregnancy.

Pediatric nurses' acceptance and attitudes toward COVID-19 vaccines for their children at Assiut university children hospital: A cross-sectional study

BackgroundChildren's vaccination mainly depends on their parents' decisions. Therefore, it is important to understand parents' acceptance and attitudes toward vaccinating their children against COVID-19. AimThe study aimed to assess the pediatric nurses' acceptance and attitudes toward COVID-19 vaccines for their children at Assiut University Children Hospital. Materials and methodA cross-sectional descriptive design was used on a convenience sample of 270 nurses who worked at Assiut University Children Hospital. ToolsTool one involved the demographic characteristics of pediatric nurses and their children. Tool two consisted of pediatric nurses' acceptance and attitudes toward COVID-19 vaccines for their children: ResultsThe results indicated that 79.3% of pediatric nurses had higher acceptance of vaccines and immunization of their children. Results also revealed that 80.0% of pediatric nurses had positive attitudes toward vaccines and their children's immunizations. ConclusionIt was concluded that most of pediatric nurses had high acceptance and positive attitudes toward vaccines and immunization of their children. Also, it was clarified that there was a positive statistically significant correlation between nurses' acceptance of vaccines and immunization of their children and their attitudes. RecommendationsContinuing education and tailored intervention should be implemented to correct misinformation and negative conceptions about the safety of vaccines for children.

Concerns about vaccines and vaccination behavior among Japanese budget travelers to India

BackgroundLow vaccination coverage among travelers poses a critical challenge to global health security. Indeed, public concerns regarding vaccines can lead to vaccine reluctance and refusal, but evidence about the impacts of concerns regarding vaccines on the uptake of travel vaccinations remains sparse. We examined the associations between concerns about vaccines and vaccination behavior among travelers. MethodsJapanese travelers aged 18 years or older, who stayed at a guesthouse in New Delhi, India, were targeted (n=153). We conducted cross-sectional surveys from August 23 to September 2, 2019, and from February 19 to March 5, 2020. We examined the associations of three concerns regarding vaccines (5-point scale)—serious side effects from vaccines, vaccine safety, and vaccine effectiveness—with the uptake of travel vaccinations. ResultsIn total, 60 participants (39.2%) had been vaccinated for this or a past trip. After adjusting for all potential confounding variables, concerns about serious side effects from vaccines and vaccine safety were negatively associated with the uptake of travel vaccinations. The ORs (95% CIs) for 1-point increases in concerns about serious side effects from vaccines and vaccine safety were 0.72 (0.52, 0.99) and 0.71 (0.52, 0.96), respectively. Sensitivity analyses did not change the results substantially. ConclusionsConcerns about vaccine safety issues were negatively associated with the uptake of travel vaccinations among the participants, with no corresponding association observed for vaccine effectiveness. Addressing concerns about vaccine safety issues, rather than vaccine effectiveness may contribute to an increased uptake of travel vaccinations.