Influence of mRNA Covid-19 vaccine dosing interval on the risk of myocarditis.

Myocarditis is the most salient serious adverse event following messenger RNA-based Covid-19 vaccines. The highest risk is observed after the second dose compared to the first, whereas the level of risk associated with more distant booster doses seems to lie in between. We aimed to assess the relation between dosing interval and the risk of myocarditis, for both the two-dose primary series and the third dose (first booster). This matched case-control study included 7911 cases of myocarditis aged 12 or more in a period where approximately 130 million vaccine doses were administered. Here we show that longer intervals between each consecutive dose, including booster, may decrease the occurrence of vaccine-associated myocarditis by up to a factor of 4, especially under age 50. These results suggest that a minimum 6-month interval might be required when scheduling additional booster vaccination.

An intranasally administered adenovirus-vectored SARS-CoV-2 vaccine induces robust mucosal secretory IgA.

BACKGROUNDThe level of nasal spike-specific secretory IgA (sIgA) is inversely correlated with the risk of SARS-CoV-2 Omicron infection. This study aimed to evaluate the safety and immunogenicity of intranasal vaccination using Ad5-S-Omicron (NB2155), a replication-incompetent human type 5 adenovirus carrying Omicron BA.1 spike.METHODSAn open-label, single-center, investigator-initiated trial was carried out on 128 health care workers who had never been infected with SARS-CoV-2 and had previously received 2 or 3 injections of inactivated whole-virus vaccines, with the last dose given 3-19 months previously (median 387 days, IQR 333-404 days). Participants received 2 intranasal sprays of NB2155 at 28-day intervals between November 30 and December 30, 2022. Safety was evaluated by solicited adverse events and laboratory tests. The elevation of nasal mucosal spike-specific sIgA and serum neutralizing activities were assessed. All participants were monitored for infection by antigen tests, disease symptoms, and the elevation of nucleocapsid-specific sIgA in the nasal passage.RESULTSThe vaccine-related solicited adverse events were mild. Nasal spike-specific sIgA against 10 strains had a mean geometric mean fold increase of 4.5 after the first dose, but it increased much higher to 51.5 after the second dose. Serum neutralizing titers also increased modestly to 128.1 (95% CI 74.4-220.4) against authentic BA.1 and 76.9 (95% CI 45.4-130.2) against BA.5 at 14 days after the second dose. Due to the lifting of the zero-COVID policy in China on December 7, 2022, 57.3% of participants were infected with BA.5 between days 15 and 28 after the first dose, whereas no participants reported having any symptomatic infections between day 3 and day 90 after the second dose. The elevation of nasal nucleocapsid-specific sIgA on days 0, 14, 42, and 118 after the first dose was assessed to verify that these 2-dose participants had no asymptomatic infections.CONCLUSIONA 2-dose intranasal vaccination regimen using NB2155 was safe, was well tolerated, and could dramatically induce broad-spectrum spike-specific sIgA in the nasal passage. Preliminary data suggested that the intranasal vaccination may establish an effective mucosal immune barrier against infection and warranted further clinical studies.TRIAL REGISTRATIONChinese Clinical Trial Registry (ChiCTR2300070346).FUNDINGNatural Science Foundation of China, Guangzhou Laboratory, The First Affiliated Hospital of Guangzhou Medical University.

Effect of vaccine dose intervals: Considering immunity levels, vaccine efficacy, and strain variants for disease control strategy.

In this study, we present an immuno-epidemic model to understand mitigation options during an epidemic break. The model incorporates comorbidity and multiple-vaccine doses through a system of coupled integro-differential equations to analyze the epidemic rate and intensity from a knowledge of the basic reproduction number and time-distributed rate functions. Our modeling results show that the interval between vaccine doses is a key control parameter that can be tuned to significantly influence disease spread. We show that multiple doses induce a hysteresis effect in immunity levels that offers a better mitigation alternative compared to frequent vaccination which is less cost-effective while being more intrusive. Optimal dosing intervals, emphasizing the cost-effectiveness of each vaccination effort, and determined by various factors such as the level of immunity and efficacy of vaccines against different strains, appear to be crucial in disease management. The model is sufficiently generic that can be extended to accommodate specific disease forms.

Vaccination strategies for patients under monoclonal antibody and other biological treatments: an updated comprehensive review based on EMA authorisations to January 2024.

INTRODUCTION: Monoclonal antibodies (mAbs) and other biological agents are being increasingly approved in the last years with very different indications. Their highly heterogeneous immunosuppressive effects, mechanisms of action and pharmacokinetics require comprehensive individualized vaccination schedules. AREAS COVERED: Vaccination for immunocompromised patients. Prevention and treatment with mAbs and other biological therapies. EXPERT OPINION: Current recommendations on vaccine schedules for patients under mAbs or other biological treatments are based on expert opinions and are not individualized according to each vaccine and treatment. No studies are focusing on the high heterogeneity of these agents, which are exponentially developed and used for many different indications. Recent paradigm changes in vaccine development (boosted by the COVID-19 pandemic) and in the mAbs use for prophylactic purposes (changing 'vaccination' by 'immunization' schedules) has been witnessed in the last years. We aimed at collecting all mAbs used for treatment or prevention, approved as of 1 January 2024, by the EMA. Based on available data on mAbs and vaccines, we propose a comprehensive guide for personalizing vaccination. Recent vaccine developments and current population strategies (e.g. zoster vaccination or prophylactic nirsevimab) are discussed. This review aims to be a practical guideline for professionals working in vaccine consultations for immunosuppressed patients.

Immunogenicity and safety of Vero cell culture-derived Japanese encephalitis vaccine: a phase 3 study in Chinese infants.

BACKGROUND: Japanese encephalitis (JE) is a severe infectious disease of the central nervous system. Vaccination with Vero cell culture-derived vaccines may effectively reduce JE incidence. RESEARCH DESIGN AND METHODS: In this single-center, randomized, blinded, positive-controlled clinical trial in China involving 600 healthy infants aged 6-11 months, participants were divided into experimental and control groups administered JEV-PI and JEV-LI, respectively. Antibody titers were determined after 0- and 7-day immunization schedules. A booster dose followed 12 months later. RESULTS: After primary vaccination and before booster vaccination, the positive conversion rate, geometric mean titer (GMT), and geometric mean increase (GMI) of JEV-PI-neutralizing antibodies exceeded those of JEV-LI. After booster immunization, the GMT and GMI of JEV-PI were higher than those of JEV-LI. After primary immunization, the local, systemic, and overall adverse reactions were of grades 1 and 2, with a low incidence of grade 3. After booster immunization, these differences were mainly grades 1 and 2, with no differences between JEV-PI and JEV-LI. CONCLUSION: JEV-PI is a promising vaccine as infants acquired long-lasting and highly neutralizing immune antibodies after inoculation with JEV-PI. TRIAL REGISTRATION: The trial was registered in the Chinese Clinical Trial Registry (https://www.chictr.org.cn/showproj.html?proj = 203130; registration number: ChiCTR2300074692; registration date: 14/08/2023).

Preferences of US adolescents and parents for vaccination against invasive meningococcal disease.

BACKGROUND: Percentage uptake of some meningococcal vaccines is low in the US. Understanding what drives vaccination preferences may help to increase vaccination rates. OBJECTIVES: To determine how attributes of meningococcal vaccines and the availability of a pentavalent (MenABCWY) vaccine profile drive adolescents' and young people's (AYP's) willingness to be vaccinated and parents' and legal guardians' (PLG') willingness for their child to be vaccinated (WTV). To also explore how preferences for meningococcal vaccines vary by participant characteristics. METHODS: Vaccine preferences were elicited in a discrete choice experiment (DCE) with AYP aged 16-23 years and PLG of adolescents aged 11-17 years. Participants chose between two hypothetical vaccine profiles that differed in level of protection, dosing, and risks of mild-to-moderate and severe side effects, and a no vaccination profile. Main outcome measures were relative attribute importance (RAI) and WTV. RAI measured the maximum contribution of an attribute to vaccination choice relative to other attributes. WTV compared predicted choice probabilities for the three vaccine profiles. RESULTS: 407 AYP and 394 PLG participated (50.9% male, 78.4% White/Caucasian). Irrespective of vaccine attributes, 59.5% always opted into vaccination and 3.6% always opted out of vaccination. The most important attributes were level of protection (RAI: 33.7%) and risk of mild-to-moderate side effects (RAI: 32.3%). Dosing was more important to PLG (RAI: 5.9%) than AYP (RAI: 2.0%; p < .01). Adding a pentavalent vaccine alternative increased WTV by 3.7 percentage points (PP) for PLG, 2.4 PP for AYP, 16.4 PP for vaccine-hesitant participants, 13.4 PP for participants without health insurance, and 9.6 PP for adults. CONCLUSION: Level of protection and risk of mild-to-moderate side effects were the most important vaccine attributes. Adding a pentavalent vaccine alternative increased WTV particularly among adults, individuals who were vaccine-hesitant, and individuals without health insurance.

Persistence of immunity in children aged 2 months and 7 months - 5 years old after primary immunization with 13-valent pneumococcal conjugate vaccine.

BACKGROUND: Pneumococcus is a common cause of pneumonia, meningitis, and other serious infections in children. The previous study has proved that the 13-valent pneumococcal conjugate vaccine (PCV13) has sufficient immunogenicity in children. The data on long-term persistence of immunity will help the follow-up development work of pneumococcal vaccines. METHODS: Children who received the full vaccination course of the tested PCV13 in the previous clinical trial were enrolled again, and these who received other pneumococcal vaccines, or were infected with one or more serotypes of S. pneumoniae corresponding to PCV13 before enrollment were excluded. Participants were divided into four groups by age which is same as that of previous trial. The study lasted for 5 years, during which we measured pneumococcal antibodies of 13 serotypes included in PCV13 at particular points in time. Geometric mean concentrations (GMCs) and seropositive rates (the rate of IgG concentration ≥0.35 µg/mL) of antibodies against 13 serotypes were calculated. RESULTS: For the participants aged 2 months, five years after primary vaccination, except for serotypes 3 and 4, seropositive rates were 100%. GMCs of IgG antibodies against 13 serotypes ranged from 0.733 to 15.160 µg/mL. All of the participants aged 7-11 months had the serotype-specific IgG concentration ≥0.35 µg/mL four years after primary vaccination with the exception of serotypes 3, 4, 6 A and 9 V. IgG GMCs were 0.753-11.031 µg/mL. All participants aged 12-23 months and 2-5 years old had the serotype-specific IgG concentration ≥0.35 µg/mL three or two years after primary vaccination respectively, except for serotype 3. IgG GMCs ranged from 0.815 to 13.111 µg/mL, and 0.684 to 12.282 µg/mL respectively. CONCLUSION: PCV13 was applied to the population aged 2 months and 7 months - 5 years old with a good immune persistence, providing more extensive evidence of long-term efficacy for that vaccine. TRIAL REGISTRATION: The trial was registered with ClinicalTrials.gov, number NCT06210737.

Cost-effectiveness of vaccinating adults aged 60 years and older against respiratory syncytial virus.

Respiratory syncytial virus (RSV) causes substantial morbidity and mortality in older adults. In May 2023, two subunit RSV vaccines (Arexvy [GSK] and Abrysvo [Pfizer]) received approval from the U.S. Food and Drug Administration (FDA). In June 2023, ACIP recommended that adults aged ≥60 years may receive a single dose of RSV vaccine, using shared clinical decision-making. In support of development of this policy, our objective was to assess the cost-effectiveness of RSV vaccination in the general population in this age group. We used a decision-analytical model of RSV over a two-year timeframe using data from published literature, FDA documents, epidemiological databases, and manufacturer data. We tracked RSV-associated outpatient, emergency department, inpatient healthcare utilization, RSV-attributable deaths, quality-adjusted life-years lost (QALYs), and societal costs. The societal cost per QALY saved from RSV vaccination depended on age group and product: adults aged ≥60 years, $196,842 for GSK's vaccine and $176,557 for Pfizer's vaccine; adults ≥65 years, $162,138 for GSK and $146,543 for Pfizer; adults 60- <65 years, $385,829 for GSK and $331,486 for Pfizer. Vaccine efficacy, incidence of RSV hospitalization, and vaccine cost had the greatest influence on cost per QALY. Cost per QALY saved decreased as the age of those vaccinated increased. Inputs such as long-term efficacy are uncertain. RSV vaccination in adults aged ≥60 years may be cost-effective, particularly in those of more advanced age. Lower vaccine acquisition costs and persistent efficacy beyond two RSV seasons would render RSV vaccination more cost-effective for a broader target population. PRIMARY FUNDING SOURCE: US Centers for Disease Control and Prevention.

Past, present, and future policy considerations regarding meningococcal vaccination in the United States.

INTRODUCTION: In 2005, the United States Advisory Committee on Immunization Practices (ACIP) recommended routine vaccination against invasive meningococcal disease (IMD) caused by serogroups A, C, W, and Y (MenACWY) for all 11-12-year-olds, as well as 2-10-year-olds at high risk. In 2010, a booster dose was recommended for all 16-year-olds, as well as for high-risk patients every 3-5 years. In 2015, optional (as opposed to routine) vaccination against meningococcal serogroup B (MenB) at the preferred age of 16-18 years was recommended (Category B, later changed to shared clinical decision-making). In 2023, a vaccine (MenABCWY) against the five serogroups primarily responsible for IMD in the U.S. became available. AREAS COVERED: This review summarizes the evolution of public policy that led to each milestone vaccine recommendation, reviews epidemiologic data published following the recommendations, and discusses the current state of meningococcal immunization policy. EXPERT OPINION: The use of MenABCWY has the potential to consolidate policy, improve coverage rates for the five serogroups, address disparities in vaccination coverage, and simplify vaccine delivery.

Evaluating the impact of extended dosing intervals on mRNA COVID-19 vaccine effectiveness in adolescents.

BACKGROUND: Extending the dosing interval of a primary series of mRNA COVID-19 vaccination has been employed to reduce myocarditis risk in adolescents, but previous evaluation of impact on vaccine effectiveness (VE) is limited to risk after second dose. METHODS: We quantified the impact of the dosing interval based on case notifications and vaccination uptake in Hong Kong from January to April 2022, based on calendar-time proportional hazards models and matching approaches. RESULTS: We estimated that the hazard ratio (HR) and odds ratio (OR) of infections after the second dose for extended (28 days or more) versus regular (21-27 days) dosing intervals ranged from 0.86 to 0.99 from calendar-time proportional hazards models, and from 0.85 to 0.87 from matching approaches, respectively. Adolescents in the extended dosing groups (including those who did not receive a second dose in the study period) had a higher hazard of infection than those with a regular dosing interval during the intra-dose period (HR 1.66; 95% CI 1.07, 2.59; p = 0.02) after the first dose. CONCLUSIONS: Implementing an extended dosing interval should consider multiple factors including the degree of myocarditis risk, the degree of protection afforded by each dose, and the extra protection achievable using an extended dosing interval.

Salp14 epitope-based mRNA vaccination induces early recognition of a tick bite.

Repeated exposure of animals to Ixodes scapularis ticks can result in acquired tick resistance (ATR). The first manifestation of ATR is erythema at the tick bite site, however, the specific peptide targets and mechanisms associated with this early aspect of ATR are not understood. In this study, we immunized guinea pigs with a lipid nanoparticle containing the mRNA encoding 25 amino acids in the carboxyl terminus of Salp14 (Salp14-C mRNA-LNP), an I. scapularis salivary protein. The animals produced high titers of IgG directed at the carboxyl terminus of Salp14. Guinea pigs immunized with Salp14-C mRNA-LNP and then exposed to I. scapularis, developed erythema at the tick bite site. Transcriptomics of the skin of guinea pigs at the I. scapularis bite sites elucidated selected pathways, including histamine activation, that are associated with the development of erythema. The study demonstrates that an mRNA vaccine encoding a small peptide can induce the initial phase of ATR in guinea pigs.

Digital Gamification Tool (Let's Control Flu) to Increase Vaccination Coverage Rates: Proposal for Algorithm Development.

BACKGROUND: Influenza represents a critical public health challenge, disproportionately affecting at-risk populations, including older adults and those with chronic conditions, often compounded by socioeconomic factors. Innovative strategies, such as gamification, are essential for augmenting risk communication and community engagement efforts to address this threat. OBJECTIVE: This study aims to introduce the "Let's Control Flu" (LCF) tool, a gamified, interactive platform aimed at simulating the impact of various public health policies (PHPs) on influenza vaccination coverage rates and health outcomes. The tool aligns with the World Health Organization's goal of achieving a 75% influenza vaccination rate by 2030, facilitating strategic decision-making to enhance vaccination uptake. METHODS: The LCF tool integrates a selection of 13 PHPs from an initial set proposed in another study, targeting specific population groups to evaluate 7 key health outcomes. A prioritization mechanism accounts for societal resistance and the synergistic effects of PHPs, projecting the potential policy impacts from 2022 to 2031. This methodology enables users to assess how PHPs could influence public health strategies within distinct target groups. RESULTS: The LCF project began in February 2021 and is scheduled to end in December 2024. The model creation phase and its application to the pilot country, Sweden, took place between May 2021 and May 2023, with subsequent application to other European countries. The pilot phase demonstrated the tool's potential, indicating a promising increase in the national influenza vaccination coverage rate, with uniform improvements across all targeted demographic groups. These initial findings highlight the tool's capacity to model the effects of PHPs on improving vaccination rates and mitigating the health impact of influenza. CONCLUSIONS: By incorporating gamification into the analysis of PHPs, the LCF tool offers an innovative and accessible approach to supporting health decision makers and patient advocacy groups. It enhances the comprehension of policy impacts, promoting more effective influenza prevention and control strategies. This paper underscores the critical need for adaptable and engaging tools in PHP planning and implementation. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR1-10.2196/55613.

HPV Infection and Prevention in Patients With Immune-Mediated Inflammatory Diseases: A Scoping Review.

BACKGROUND/HISTORICAL PERSPECTIVE: Human papillomavirus (HPV) infections are a significant public health concern as they cause various cancers, including those of the cervix, vulva, vagina, anus, penis, and oropharynx, in both women and men. SUMMARY INTEGRATING THE CURRENT PUBLISHED LITERATURE: Individuals with immune-mediated inflammatory diseases, particularly systemic lupus erythematosus, have an increased risk of developing persistent HPV infection and subsequent precancerous lesions due to their immunosuppression. MAJOR CONCLUSIONS: Vaccination and screening for precancerous lesions are 2 central management strategies that must be implemented in patients with immune-mediated inflammatory diseases. Although HPV vaccination has been proven to be safe and effective in these patients, coverage remains low and should be encouraged. Screening for cervical cancer should be more widely implemented in this population, as recommended in guidelines for other immunosuppressed patients. FUTURE RESEARCH DIRECTIONS: Catch-up vaccination, vaginal self-sampling screening for HPV detection, and therapeutic vaccination are new options that should be considered.

The Impact of COVID-19 Third Dose Vaccination on the Magnitude of Antigen Specific T Cells in Kidney Transplant Patients.

Measuring T cell response can add information about antivirus immunity provided by antibody test results. The study evaluates the impact of a third mRNA COVID-19 vaccine dose on T cell response and antibody production in kidney transplant recipients (25 KTRs) versus healthy controls (26 Hc). Results show a significant rise in S-activated CD4+CD154+IFN?+TNF?+ double producer cells in both KTRs (p=0.025) and Hc (p=0.009) as well as increased spike antibody response in KTRs (p=0.00019) and Hc (p=3.10-8) third-month post-third dose. Moreover, the study revealed a drop in seronegative KTRs (non-responders) from 9/25 (36%) pre-third dose to 2/25 (7%) at 3 months post-third dose while 5/9 (56%) of non-responders post-second dose showed specific T cell responses. Notably, the third dose significantly improved seroconversion rates in both KTRs and Hc, although Hc individuals exhibited higher antibody levels. Key words: mRNA COVID-19 vaccine, T cells, SARS-CoV-2 antibodies, Kidney transplantation, mRNA vaccination.

Early transcriptomic response of innate immune cells to subcutaneous BCG vaccination of mice.

OBJECTIVES: Current data suggests that Bacille Calmette-Guerin (BCG) vaccination contributes to nonspecific enhancement of resistance to various infections. Thus, BCG vaccination induces both specific immunity against mycobacteria and non-specific "trained immunity" against various pathogens. To understand the fundamental mechanisms of "trained" immunity, studies of transcriptome changes occurring during BCG vaccination in innate immunity cells, as well as in their precursors, are necessary. Furthermore, this data possesses important significance for practical applications associated with the development of recombinant BCG strains aimed to enhance innate immunity against diverse infectious agents. DATA DESCRIPTION: We performed RNA sequencing of innate immune cells derived from murine bone marrow and spleen three days after subcutaneous BCG vaccination. Using fluorescence-activated cell sorting we obtained three cell populations for each mouse from both control and BCG vaccinated groups: bone marrow monocytes and neutrophils and splenic NK-cells. Then double-indexed cDNA libraries for Illumina sequencing from the collected samples were prepared, the resulting cDNA library mix was subjected to NovaSeq 6000 sequencing. This paper describes the collection of 24 RNA sequencing samples comprising 4 sets of immune cell populations obtained from subcutaneously BCG-vaccinated and control mice.

Booster vaccination using bivalent DS-5670a/b is safe and immunogenic against SARS-CoV-2 variants in children aged 5-11 years: a phase 2/3, randomized, active-controlled study.

Background: DS-5670 is a messenger ribonucleic acid (mRNA) vaccine platform targeting the receptor-binding domain (RBD) of the spike protein derived from severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). Booster vaccination against coronavirus disease 2019 (COVID-19) with monovalent DS-5670a (incorporating mRNA encoding the RBD from the original SARS-CoV-2 strain) or bivalent DS-5670a/b (original and omicron BA.4-5 RBD antigens) is effective and safe in adults. Data from a phase 2/3 active-controlled, non-inferiority, pediatric study evaluating a third booster dose of DS-5670a/b are reported here. Methods: Children aged 5-11 years who had completed the two-dose primary vaccination series with monovalent BNT162b2 (original strain) at least 3 months prior to enrolment were randomly assigned to receive DS-5670a/b (20 µg of mRNA) or bivalent BNT1 62b2 (original/omicron BA.4-5; 10 µg of mRNA) on Day 1. The primary efficacy endpoint was blood neutralization geometric mean titer (GMT) against SARS-CoV-2 (omicron variant BA.5.2.1) and immune response rate (≥ 4-fold increase in post-vaccination circulating anti-SARS-CoV-2 neutralizing activity) on Day 29. Results: Among evaluable participants (DS-5670a/b, n = 74; bivalent BNT162b2, n = 75), the adjusted GMT ratio of DS-5670a/b to bivalent BNT162b2 on Day 29 was 1.636 (95% CI, 1.221, 2.190). Immune response rates were ≥ 89% with both study vaccines; adjusted difference 2.6% (95% CI, -7.8, 13.8). The prespecified non-inferiority margins were exceeded, and the study met the primary endpoint. DS-5670a/b also demonstrated broad neutralization activity across recent omicron sublineages and no cases of COVID-19 between Days 8-29 post-administration were reported. There were no novel safety concerns in the pediatric population at data cut-off. Conclusions: Bivalent DS-5670a/b was non-inferior to bivalent BNT162b2 in terms of immunogenicity, and had a manageable safety profile, when administered as a heterologous booster in children aged 5-11 years. Clinical trial registration: https://jrct.niph.go.jp/, identifier jRCT2031220665.

Immunization strategies for individuals with sickle cell anemia: A narrative review.

Sickle cell anemia (SCA) is a hereditary blood disorder characterized by the production of abnormal hemoglobin, leading to the formation of sickle-shaped red blood cells. These distorted cells can obstruct blood flow, causing vaso-occlusive crises and increasing the risk of severe infections due to functional asplenia and immune system dysregulation. Immunization is a crucial strategy to mitigate infection-related complications in individuals with SCA, necessitating a comprehensive and tailored vaccination approach. Current immunization guidelines for individuals with SCA recommend a combination of standard and additional vaccines to address their heightened susceptibility to infections. Key vaccines include pneumococcal conjugate (PCV13) and polysaccharide (PPSV23) vaccines, meningococcal conjugate (MenACWY) and serogroup B (MenB) vaccines, Haemophilus influenzae type b (Hib) vaccine, annual influenza vaccine, and hepatitis A and B vaccines. These vaccinations aim to provide broad protection against pathogens that pose significant risks to patients with SCA. Despite generally adequate immune responses, the variability in vaccine efficacy due to immune dysfunction necessitates booster doses and additional vaccinations. This narrative review highlights the importance of adhering to current immunization recommendations and addresses challenges such as access to care, vaccine hesitancy, and monitoring vaccination status.

Vaccination and Therapeutics.

In the wake of the novel Coronavirus, it has become imperative to develop vaccines that can alert our immune system to the virus, hence reducing the severity of disease if exposed to it. Different types of vaccines have been studied in this respect, such as nucleic acid vaccines (mRNA and DNA vaccines), vector-based vaccines, whole-virus vaccines (inactivated virus and live-attenuated vaccine), as well as protein subunits vaccines. The results have demonstrated that these vaccines are efficient against both the original strain and emerging variants. Furthermore, they also proved their safety with no grave adverse events. Despite this, hesitancy toward taking these vaccines is still present among certain groups in society due to various factors. Special emphasis has been placed on studies concerning pregnant women, children, elderly people, and immunocompromised individuals where efficacy and safety were proven.

Does the COVID-19 Vaccination Reduce the Risk to Transmit SARS-CoV-2 to Others?

It has been assumed that the COVID-19 vaccination reduces the risk of transmission to others. Results during the delta predominance show that the viral load in the vaccinated population is not consistently lower compared to the unvaccinated, and during the omicron predominance, the viral load was even somewhat higher. Levels of infectious SARS-CoV-2 were partly lower in the vaccinated population. Viral loads were mostly lower in re-infections compared to breakthrough infections. Viral clearance including the detection of infectious virus has mostly been described to be faster in the vaccinated population suggesting a shorter duration as a possible source for transmission. The epidemiological relevance of this finding remains uncertain. Approximately half of the transmission studies found lower secondary attack rates from the fully vaccinated population, but the results are probably best explained by the vaccination status of the contact population. Public health data from the UK show that the number of COVID-19 cases is higher among the fully vaccinated and boosted population who might be possible sources, in contrast to lower case numbers within the first three months among the vaccinated obtained in phase 3 trials on symptomatic cases. Overall, there is no convincing evidence that the COVID-19 vaccination significantly reduces the risk to transmit SARS-CoV-2 to others.

Understanding Barriers to Establishing Public JYNNEOS Mpox Vaccination Clinics in New Hampshire: Mpox vaccine clinic NH.

OBJECTIVE: 2022 - 2023 mpox outbreak necessitated rapid distribution of JYNNEOS vaccines from US Strategic National Stockpile to state and local public health agencies. New Hampshire's centralized public health structure required partnering with healthcare facilities to reach at-risk persons. Among the 67 organizations contacted to partner with, only 7 established public JYNNEOS vaccine clinics. The study objective was to identify barriers and resources needed for emergency public vaccination. METHODS: In March 2023, mixed-method surveys were developed and sent to 20 non-participating organizations and 7 participating organizations ("vaccine-partners"). RESULTS: 35% (7/20) of non-participating organizations and 100% (7/7) vaccine-partners responded. Non-participating organizations (n = 5) identified lack of staffing (100%) and insufficient provider time or clinical resources (80%) as the most common barriers. Staffing needs reported by non-participating organizations included: administrative (100%); medical doctor or advanced practice practitioner (67%); and registered nurse, medical assistant, or licensed nursing assistant (67%). Vaccine partners reported similar staffing requirements. Estimated additional monthly funding needs were $3,750 for non-participating organizations and $1,680 for vaccine-partners. CONCLUSIONS: A minority of NH healthcare facilities established public JYNNEOS vaccination clinics. The primary barrier was insufficient staffing; additional resources and funding needs were modest. Success of the next emergency vaccination campaign depends on sustained advocacy, resources, and partnership.