Annual Booster Research Articles

Vaccinations in pulmonary diseases - part 2: herpes zoste, RSV, pneumococcal infection and pertussis

RSV is a common cause of respiratory tract infections, posing a risk of severe disease, particularly for newborns and infants, as well as in older individuals with pre-existing conditions. Two safe and effective RSV vaccines were approved in 2023. These vaccines elicit protective antibodies and offer robust protection with no additional benefit from annual boosters. Both vaccines have been approved for individuals aged 60 years and older, while one of the vaccines has also been approved in pregnant women to elicit maternal immunity for passive protection of the unborn child. In Germany, RSV vaccination is currently recommended for all individuals aged 75 years and older, as well as people aged 60-74 years of age with severe underlying conditions. PNEUMOCOCCAL INFECTION: Streptococcus pneumoniae is a primary cause of community-acquired pneumonia (CAP). Since early 2022, a 20-valent conjugate vaccine (PCV20) is approved and recommended for people over 60 years of age and individuals over 18 years of age with risk factors. PCV20 replaces the 23-valent polysaccharide vaccine (PPV23) previously recommended for those over 60 years of age. Although viewed primarily as a childhood disease, the majority of infections affect adults. Patients with chronic respiratory diseases are at a higher risk for severe clinical course of pertussis infection. It has therefore been recommended that all adults should get a pertussis booster with their next scheduled tetanus vaccination, given as a combination vaccine (Tdap). For risk groups (healthcare personnel, community facilities) a booster vaccination every 10 years is recommended. Herpes Zoster (shingles) is caused by the varicella-zoster virus, and reactivations can lead to painful skin lesions and potential complications such as herpes zoster oticus, meningitis, or postherpetic neuralgia. People with chronic lung diseases such as COPD or asthma are at increased risk of herpes zoster-related complications. A recombinant adjuvanted inactivated vaccine was approved in 2018 and offers robust protection against herpes zoster and its complications. The vaccine is recommended for all people over 60 years of age and for certain risk groups over 50 years of age.

Cost effectiveness analysis comparing varying booster intervals of vaccination policies to address COVID-19 situation in Thailand, 2023.

The COVID-19 booster immunization policy is cost-effective, but evidence on additional booster doses and appropriate strategies is scarce. This research compared the cost-effectiveness of annual, twice-a-year, and biennial booster dose policies. We performed stochastic modeling using compartmental susceptible-exposed-infectious-recovered models and a system dynamic model. We evaluated four policy scenarios: (1) hypothetical no-booster immunization policy; (2) twice-a-year vaccination policy; (3) annual vaccination policy; and (4) biennial vaccination policy. In addition, we conducted a one-way sensitivity analysis by adjusting R0 from 1.8 to 3.0 in all scenarios (epidemic stage) and by decreasing the vaccination cost by 50% at the end of the first year to reflect the current policy direction to enhance domestic vaccine production. Compared to non-booster policies, all three booster strategies reduced the number of cases, hospital admissions, and severe infections remarkably. Without a booster, total cases would reach 16,220,615 (95% confidence interval [CI] 6,726,550-29,661,112) by day 1,460, whereas, with a twice-a-year booster, the total cases would reach 597,901 (95% CI 526,230-694,458) in the same period. Even though the no booster scenario exhibited the lowest cost by approximately the first 500 days, by day 1,460 the biennial booster scenario demonstrated the lowest cost at 72.0 billion baht (95% CI 68.6-79.4 billion). The most cost-saving policy was the biennial booster scenario. The annual booster scenario also stood as a cost-effective option for most outcomes. In the epidemic stage and in an assumption where the vaccination costs dropped, all booster policies became more cost-effective or cost-saving compared with the main assumption. This study underscores the significance of the COVID-19 vaccine booster policy. Implementing policies should take into consideration cost-effectiveness, feasibility, and public communication.

Factors affecting the outcome of primary rabies vaccination in young cats

Limited data exist on the factors affecting feline rabies vaccination outcomes during primary immunization. This study aimed to assess if specific factors (signalment, vaccination count, vaccine brand, and time since last vaccination) correlated with meeting global antibody titer standards and absolute titers in young cats given monovalent inactivated rabies vaccines. Analyzing a dataset from cats tested before their first annual booster using the FAVN test, logistic and linear regression models were applied. Among 379 cats, 94.2 % achieved titers meeting or exceeding the standard threshold (≥0.5 IU/ml). Time since last vaccination proved to be the primary predictor of vaccination success. Cats receiving two vaccinations tended toward higher titers. Age, sex, breed, and vaccine type showed no impact on outcomes. The present study indicates that vaccination failure in young cats is uncommon, and that the time interval from the latest vaccination is the single most important predictor of successful rabies vaccination.

Immunogenicity and safety of an 18-month booster dose of the VLA15 Lyme borreliosis vaccine candidate after primary immunisation in healthy adults in the USA: results of the booster phase of a randomised, controlled, phase 2 trial

Incidence rates of Lyme borreliosis, a tickborne disease attributed to infection by Borrelia species, are increasing, and limitations to existing treatments potentiate the possibility of severe outcomes. Nevertheless, there are no licensed vaccines for Lyme borreliosis prevention in humans. This study investigated the immunogenicity and safety of a booster dose of VLA15, an investigational outer surface protein A (OspA)-based Lyme borreliosis vaccine that has previously shown safety and immunogenicity when administered as a primary vaccination series, following a primary VLA15 vaccination series. We report the results of the booster phase of a randomised, observer-blinded, placebo-controlled, multicentre, phase 2 study that enrolled healthy adults aged 18-65 years from five US clinical study centres to receive 135 μg or 180 μg VLA15 or placebo at months 0, 2, and 6 in the main study phase. Participants who received 180 μg VLA15 in the main study phase and did not have relevant protocol deviations were eligible for the booster phase (months 18-30). Participants were randomly reassigned (2:1) to receive an intramuscular injection of a VLA15 booster or placebo 1 year after the completion of primary vaccination (month 18) via a randomisation list generated by an unmasked statistician with a block size of six. Individuals involved in data safety monitoring, rerandomisation, vaccine handling, and vaccine accountability were unmasked; the study sponsor and statisticians were only unmasked after analysis of data up to 1 month after booster administration. All other individuals remained masked throughout the booster phase. The outcomes for the booster phase were the immunogenicity (evaluated in the booster per-protocol population) and safety (evaluated for all participants who received the booster) of the booster dose up to month 30. The study is registered at ClinicalTrials.gov (NCT03970733) and is completed. Between Feb 4 and March 23, 2021, 58 participants (28 men and 30 women) were screened, randomly assigned, and received VLA15 (n=39) or placebo (n=19). One participant in the placebo group was lost to follow-up. The IgG geometric mean titres for each OspA serotype (serotypes 1-6) in the VLA15 group peaked at 1 month after the booster dose (1277·0 U/mL [95% CI 861·8-1892·3] to 2194·5 U/mL [1566·8-3073·7] vs 23·6 U/mL [18·1-30·8] to 36·8 U/mL [26·4-51·3] in the placebo group [p<0·0001 for all serotypes]), remained elevated at month 24 (137·4 U/mL [95·8-196·9] to 265·8 U/mL [202·9-348·2] vs 22·3 U/mL [17·7-28·0] to 29·1 U/mL [20·8-40·6] in the placebo group; p<0·0001 for all serotypes), and declined by month 30 (54·1 U/mL [38·6-75·7] to 101·6 U/mL [77·6-133·1] vs 21·9 U/mL [18·0-26·6] to 24·9 U/mL [19·0-32·6] in the placebo group; p<0·0001 for all serotypes except serotype 1 [p=0·0006]). Solicited local adverse events were reported more frequently in the VLA15 group (35 [92%, 95% CI 79-97] of 38 participants) than the placebo group (six [32%, 15-54] of 19 participants; p<0·0001) after booster vaccination. There was no significant difference in the frequency of solicited systemic adverse events between groups (20 [59%, 42-74] of 34 participants in the VLA15 group vs six [38%, 18-61] of 16 participants in the placebo group). Related unsolicited adverse events (none severe) were reported by two (5%, 1-17) of 39 participants in the VLA15 group and none (0%, 0-17) of 19 participants in the placebo group. There were no severe solicited local or systemic adverse events or deaths during the study. A booster dose of VLA15 is safe and induces substantial anamnestic immune responses against all six OspA serotypes. As with previously investigated OspA-based Lyme borreliosis vaccines, waning immune responses were observed with VLA15, and annual boosters might therefore be required. Valneva.

Risks of SARS-CoV-2 JN.1 infection and COVID-19 associated emergency-department (ED) visits/hospitalizations following updated boosters and prior infection: a population-based cohort study.

Data on protection afforded by updated COVID-19 vaccines (bivalent/XBB 1.5 monovalent) against the emergent JN.1 variant remains limited. We conducted a retrospective population-based cohort study amongst all boosted Singaporeans aged ≥18 years during a COVID-19 wave predominantly driven by JN.1, from 26th November 2023 to 13th January 2024. Multivariable Cox regression was utilised to assess risk of SARS-CoV-2 infection and COVID-19 associated emergency-department (ED) visits/hospitalizations, stratified by vaccination status/prior infection; with individuals last boosted ≥1 year utilized as the reference category. Vaccination and infection status were classified using national registries. 3,086,562 boosted adult Singaporeans were included in the study population, accounting for 146,863,476 person-days of observation. During the JN.1 outbreak, 28,160 SARS-CoV-2 infections were recorded, with 2,926 hospitalizations and 3,747 ED-visits. Compared with individuals last boosted ≥1 year prior with ancestral monovalent vaccines, receipt of an updated XBB.1.5 booster 8-120 days prior was associated with lower risk of JN.1 infection (adjusted-hazard-ratio, aHR = 0.59[0.52-0.66]), COVID-19 associated ED-visits (aHR = 0.50[0.34-0.73]) and hospitalizations(aHR = 0.58[0.37-0.91]), while receipt of a bivalent booster 121-365 days prior was associated with lower risk of JN.1 infection (aHR = 0.92[0.88-0.95]) and ED-visits (aHR = 0.80[0.70-0.90]). Lower risk of COVID-19 hospitalization during the JN.1 outbreak (aHR = 0.57[0.33-0.97]) was still observed following receipt of an updated XBB.1.5 booster 8-120 days prior, even when analysis was restricted to previously infected individuals. Recent receipt of updated boosters conferred protection against SARS-CoV-2 infection and ED-visits/hospitalization during a JN.1 variant wave, in both previously infected and uninfected individuals. Annual booster doses confer protection during COVID-19 endemicity.

Healthcare workers' attitudes toward and factors influencing their acceptance of an annual COVID-19 booster vaccine: a cross-sectional study in Palestine

BackgroundThe emergence of several SARS-CoV-2 variants may necessitate an annual COVID-19 booster vaccine. This study aimed to evaluate healthcare workers' (HCWs) acceptance of a COVID-19 yearly booster vaccine if recommended and its association with their attitudes and burnout levels.MethodsWe used an online self-administered questionnaire to conduct a cross-sectional study of all HCWs in the West Bank and Gaza Strip of Palestine between August and September 2022. We used the Vaccination Attitudes Examination scale to assess HCWs' vaccination attitudes and the Maslach Burnout Inventory to assess work-related Burnout. In addition, we conducted logistic regression to identify factors independently associated with the acceptance of the booster vaccine.ResultsThe study included 919 HCWs; 52.4% were male, 46.5% were physicians, 30.0% were nurses, and 63.1% worked in hospitals. One-third of HCWs (95% CI: 30.5%-36.7%) said they would accept an annual COVID-19 booster vaccine if recommended. HCWs who are suspicious of vaccine benefits [aOR = .70; 95%CI: .65-.75] and those concerned about unforeseeable future effects [aOR = .90; 95%CI: .84-.95] are less likely to accept the booster vaccine if recommended, whereas those who receive annual influenza vaccine are more likely to get it [aOR = 2.9; 95%CI: 1.7–5.0].ConclusionOnly about a third of HCWs would agree to receive an annual COVID-19 booster vaccine if recommended. Mistrust of the vaccine's efficacy and concerns about side effects continue to drive COVID-19 vaccine reluctance. Health officials need to address HCWs' concerns to increase their acceptance of the annual vaccine if it is to be recommended.

Comparing frequency of booster vaccination to prevent severe COVID-19 by risk group in the United States

There is a public health need to understand how different frequencies of COVID-19 booster vaccines may mitigate the risk of severe COVID-19, while accounting for waning of protection and differential risk by age and immune status. By analyzing United States COVID-19 surveillance and seroprevalence data in a microsimulation model, here we show that more frequent COVID-19 booster vaccination (every 6–12 months) in older age groups and the immunocompromised population would effectively reduce the burden of severe COVID-19, while frequent boosters in the younger population may only provide modest benefit against severe disease. In persons 75+ years, the model estimated that annual boosters would reduce absolute annual risk of severe COVID-19 by 199 (uncertainty interval: 183–232) cases per 100,000 persons, compared to a one-time booster vaccination. In contrast, for persons 18–49 years, the model estimated that annual boosters would reduce this risk by 14 (10–19) cases per 100,000 persons. Those with prior infection had lower benefit of more frequent boosting, and immunocompromised persons had larger benefit. Scenarios with emerging variants with immune evasion increased the benefit of more frequent variant-targeted boosters. This study underscores the benefit of considering key risk factors to inform frequency of COVID-19 booster vaccines in public health guidance and ensuring at least annual boosters in high-risk populations.

Detection of Coxiella burnetii in the mammary gland of a dairy goat

The zoonotic bacterium Coxiella (C.) burnetii can be excreted by infected goats through birth products and milk. The detection of C. burnetii DNA in the mammary gland tissue of infected dairy goats and intermittent milk shedders has been reported, but confirmation of C. burnetii bacteria in the udder remained pending. The pathogen caused abortions in a 152-head dairy goat herd, resulting in the vaccination against C. burnetii of the entire herd with annual boosters. To monitor the C. burnetii shedding at herd level, monthly bulk tank milk (BTM) samples were analyzed using PCR (IS1111). Despite vaccination, C. burnetii DNA was detected in BTM samples within the first 16 months of the study. Therefore, individual milk samples were tested on four different occasions several months apart to identify potential intermittent milk shedders. Only one goat (#67455) tested positive three times. This goat was necropsied to investigate the presence of C. burnetii in the udder and other organs. PCR detected C. burnetii DNA solely in both mammary glands and the left teat cistern. Immunohistological examination identified C. burnetii antigen in mammary gland tissue, confirmed by the detection of C. burnetii bacteria in the mammary epithelial cells using fluorescence in situ hybridization. The removal of goat #67455 led to negative BTM samples until the end of the study. The findings demonstrate the occurrence of C. burnetii in the mammary gland of a naturally infected and vaccinated goat. The presence possibly contributed to intermittent milk shedding of goat #67455, and the mammary gland tissue may serve as a replicative niche for C. burnetii.

Social Network, Trust, Approval of President Biden, Risk Perception, and Annual COVID-19 Booster Intention

The aim of this study is to understand the American public’s attitudes toward the annual coronavirus disease booster vaccination, administered beginning in the fall of 2023. The authors carried out a national survey in the spring of 2023, with 40 percent of respondents saying that they are “very likely” to receive the regular booster when it becomes available. Several underlying predictors are identified through structural equation modeling analyses. People with more vaccine takers in their social circles, greater trust in others, higher approval of President Biden’s performance, and greater perceived risk of the pandemic are more likely to receive regular boosters. The social network has the most considerable influence, with the largest coefficient size after comparing all standardized coefficients. The effect of trust is enhanced through social networks, and there is a combined effect of President Biden’s approval and risk perception. These findings contribute to the literature and have policy implications for leveraging interventions and optimizing the vaccination campaign.

Breakthrough infections and acceptance of COVID-19 vaccine boosters: A survey analysis.

This Short Communication explores the effect of COVID-19 breakthrough infections (defined as a COVID-19 diagnosis after vaccination) on the willingness of previously vaccinated individuals to receive ongoing vaccine boosters. Specifically, we examine unique effects for three different breakthrough infection experiences, including the participant themselves, a close member of their family, and a friend/coworker. A representative, web-based survey of 600 adults in the state of Florida was fielded in March/April of 2022. Among the respondents, 455 had been vaccinated against COVID-19. Their responses were analyzed for this study using both descriptive and inferential statistical methods. Individuals who have experienced a personal breakthrough infection are two times less likely to receive annual vaccine boosters, ceteris paribus. However, there is not a statistically significant relationship between vaccine acceptance and breakthrough infections among close family members or friends/coworkers. We also found a very strong relationship between vaccine decisions and confidence in public health guidance. Our findings show that confidence in public health guidelines is the most compelling determinant of vaccine acceptance, but breakthrough infections also have a significant impact on individual decision making when it comes to ongoing vaccination. Going forward, public health messaging should directly account for this correlation in order to effectively maintain vaccination levels. The COVID-19 pandemic marked a turning point in the development and deployment of mRNA vaccines. This study contributes to innovation in health communication research by examining how breakthrough infections in these vaccinated individuals impacts ongoing booster shot acceptance. The findings of this study contribute to the nascent and ongoing development of baseline research in this area.

Acceptance of Annual Booster Doses of COVID-19 Vaccines Among Indian Healthcare Professionals: A Pan-India Cross-Sectional Survey.

Introduction The emergence of coronavirus disease 2019 (COVID-19) posed significant challenges to global health, leading to the declaration of a pandemic by the World Health Organization. Vaccination efforts have effectively reduced severe outcomes and mortality, but breakthrough infections and new variants are of concern. In response, annual booster doses of COVID-19 vaccines are being considered to maintain immunity. Healthcare professionals, as frontline workers, play a pivotal role in vaccination campaigns. This study explores their attitudes toward and willingness to accept annual COVID-19 booster doses in India. Methods A pan-India cross-sectional survey was conducted among healthcare professionals, including faculty, resident doctors, interns, and nursing staff, across Indian medical and nursing colleges. Convenience sampling was used to collect responses via an online questionnaire. The questionnaire assessed demographics, vaccine status, attitudes toward COVID-19 vaccination, and willingness to accept annual booster doses. Multivariate analysis was performed to identify predictors of booster dose acceptance. Results A total of 535 participants responded from 28 states and 8 union territories of India. Most were 34.2 years (± 11.1 SD), and 372 (69.5%) had taken Covishield (Serum Institute of India, Pune, India) as their primary vaccine. While 525 (98.1%) had taken the first dose and 518 (96.8%) of them had taken the second dose, only 333 (62.2%) had received a booster. Around 318 (60%) of healthcare professionals were willing to accept an annual booster dose. The mean attitude score toward annual booster doses was 75.4 (range: 28-111). Healthcare professionals' trust in government recommendations and medical experts significantly influenced their willingness to accept annual booster doses. Conclusion This study provides insights into the attitudes of healthcare professionals in India toward annual COVID-19 booster doses. At the same time, a significant proportion showed a willingness to accept boosters.

Acceptance of COVID-19 boosters among hypertensive patients in China: A multicenter cross-sectional study

ABSTRACT Hypertension, a prevalent chronic disease, has been associated with increased COVID-19 severity. To promote the COVID-19 booster vaccination of hypertensive patients, this study investigated the willingness to receive boosters and the related influencing factors based on the health belief model (HBM model). Between June and October 2022, 453 valid questionnaires were collected across three Chinese cities. The willingness to receive a booster vaccination was 72.2%. The main factors that influenced the willingness of patients with hypertension to receive a booster shot were male (χ2 = 7.008, p = .008), residence in rural (χ2 = 4.778, p = .029), being in employment (χ2 = 7.232, p = .007), taking no or less antihypertensive medication (χ2 = 9.372, p = .025), with less hypertension-related comorbidities (χ2 = 35.888, p < .0001), and did not have any other chronic diseases (χ2 = 28.476, p < .0001). Amid the evolving COVID-19 landscape, the willingness to receive annual booster vaccination was 59.4%, and employment status (χ2 = 10.058, p = .002), and presence of other chronic diseases (χ2 = 14.256, p < .0001) are associated with the willingness of annual booster vaccination. Respondents with higher perceived severity, perceived benefits, perceived self-efficacy, and lower perceived barriers were more willing to receive booster shots. The mean and median value of willingness to pay (WTP) for a dose of booster were 53.17 CNY and 28.31 CNY. Concerns regarding booster safety and the need for professional advice were prevalent. Our findings highlight the importance of promoting booster safety knowledge and health-related management among hypertensive individuals through professional organizations and medical specialists.

Knowledge, acceptance, motivators and barriers of booster dose of COVID-19 vaccination among dental patients: A cross-sectional study.

Given the lingering threat of COVID infection, questions are being raised if coronavirus disease 2019 (COVID-19) vaccine needs annual or regular boosters to maintain high levels of immunity against both the original virus and variants. This study was designed to evaluate the knowledge, acceptance, motivators and barriers of the booster dose of COVID-19 vaccine among the dental patients of District Lucknow, India. A total of 297 respondents were selected by a convenience sampling method in this cross-sectional study from various dental clinics. An anonymous, self-administered, closed-ended questionnaire was used. Overall 37.7% respondents reported to have taken all 3 doses and 57.9% had taken single/double doses. Correct information about booster doses shows a significant association with the number of doses taken. The majority had information about the availability of the Pfizer booster vaccine (69.0%). About 58% of participants had information about the technology used in booster doses. The hesitancy for booster doses and the development of natural immunity by infection show significant associations with the number of doses taken. Only 18.2% patients had hesitation about the booster dose and most of them 78.8% recommended others to take the booster vaccine as soon as possible. The majority assumed that previous COVID-19 vaccines can help them get immune (21.5%) followed by not much research has been done on the booster vaccines (15.5%) and their chronic diseases warn them against the booster dose administration (12.5%). Nearly 18.2% of respondents had hesitation about booster dose and less than one third of the respondents trusted a government source for information about booster dose of COVID vaccine. Nearly 36 % did not know that the booster dose of COVID vaccine is available at health centers. Dental health professionals and policymakers should implement and support strategies to ensure people are vaccinated for COVID-19 booster doses.

B-077 Comparison of SARS-CoV-2 Antibody Profile and Omicron-Specific Neutralizing Activity Before and After mRNA Booster Vaccines: Bivalent vs. Original Formulation

Abstract Background With entering into the era of SARS-CoV-2 vaccine boosters and shifting from pandemic to endemic, understanding how boosters change antibody levels and durability is important for vaccination strategies. This study investigated antibodies against different antigens and neutralizing antibody levels in immunocompetent healthcare workers who have received the primary 2 doses and booster mRNA vaccines. Method The study included two cohorts. Cohort 1 received 3 doses of the original vaccine and cohort 2 received the 3 original doses plus the 4th bivalent booster. Two blood samples were collected from each participant before the 3rd (pre-3) or 4th dose (pre-4) and 14–30 days after the 3rd (post-3) or 4th dose (post-4). SARS-CoV-2 IgG antibodies against the spike protein receptor-binding domain (RBD), S1, S2, and nucleocapsid protein were measured using a semi-quantitative multiplex assay on a Bioplex 2200 analyzer. Neutralizing antibodies against omicron sublineage BA.2 were determined using a surrogate virus neutralization assay. Results Among the 45 participants aged 24 to 66, 53% had natural infection evidenced by positive anti-nucleocapsid IgG or historical PCR results. In cohort 1 (n = 24), the median time between the second and third doses was 375 (range 278–439) days. In cohort 2 (n = 21), the median time between the third and fourth doses was 353 (range 102–438) days. Both the 3rd original and 4th bivalent vaccines significantly increased neutralizing, anti-RBD, anti-S1 and anti-S2 antibodies when compared to their pre-dose concentrations (P &amp;lt; 0.01). The median and interquartile range (IQR) for pre-and post-booster antibody levels were: Neutralizing antibody post-3 median: 189 U/mL (IQR 99–781) versus pre-3 median: 44 U/mL (IQR 0–180), post-4 median: 241 U/mL (IQR 148–630) versus pre-4 median: 37 U/mL (IQR 8–167); anti-RBD post-3 median: 13 100 U/mL (IQR 8001–31 850) versus pre-3 median: 3437 U/mL (IQR 201–7976), post-4 median: 16 490 U/mL (IQR 7691–24 710) versus pre-4 median: 3270 U/mL (IQR 1970–4847); anti-S1 post-3 median: 9700 U/mL (IQR 7281–27 425) versus pre-3 median: 2287 U/mL (IQR 229–7710), post-4 median: 11 000 U/mL (IQR 6935–20 665) versus pre-4 median: 2280 U/mL (IQR 1419–2833); and anti-S2 post-3 median: 148 U/mL (IQR 89–266) versus pre-3 median: 25 U/mL (IQR 9–51), post-4 median: 101 U/mL (IQR 73–280) versus pre-4 median: 28 U/mL (IQR 14–43). No difference was found between the post-4-bivalent and post-3-original antibody levels. The difference in post/pre ratios elicited by the 3rd and 4th doses was also not statistically significant (P &amp;gt; 0.05). Further analysis showed participants with natural COVID infection had much higher pre-3 and pre-4 dose antibody levels than those without natural infection (P &amp;lt; 0.01). The pre-booster neutralizing antibody levels of infected participants were not significantly different (P &amp;gt; 0.05) from the post-booster levels of the non-infected participants. This pattern was consistent across antibodies against different antigens. In addition, there was no significant difference in post-booster antibodies between previously infected and non-infected participants. Conclusion The bivalent and original mRNA vaccines are equally effective in enhancing immunity against SARS-CoV-2. Individuals with no previous COVID infection may need boosters annually to raise waning antibodies. Naturally infected individuals demonstrated long-lasting immunity and may not require annual boosters.

699 Audit of Post-Splenectomy Patients in Primary Care

Abstract Aim To describe the demographics of a large general practices post-splenectomy patient population (including sex, age, and indication for splenectomy), and audit of cohort's care against national immunisation and antibiotic prophylaxis guidelines. Method All adult patients registered with the practice who had undergone surgical splenectomy were included. Included patients’ medical records were reviewed and data including sex; age; date and indication of splenectomy; immunisation history; and drug history were collected. Results Fifteen of approximately 13,000 registered patients were coded for having previously undergone surgical splenectomy. The main indications included trauma; haematological disease; major intra-abdominal resection. Patient cohort were of an older patient population (mean age 69) having undergone splenectomy several years previously (mean 39 years ago). Three patients had outstanding pneumococcal vaccine in the past five years, however there was 100% compliance with annual influenza vaccine. All patients had received a minimum of two COVID vaccinations. Variation in prescribed phenoxymethylpenicillin dose, with two patients on incorrect antibiotic prophylaxis, and four patients without antibiotic prophylaxis. Conclusions Despite our small patient cohort, this audit highlighted variation and deficiencies in patient care, and has led to a recall of patients with outstanding pneumococcal vaccination and review of antibiotic prophylaxis offered to patients. Additionally, there is no national recommendation that post-splenectomy patients should be offered an annual COVID booster. We recommend that this is reviewed urgently by public health officials due to an increased risk of secondary pneumococcal infection with COVID infection, which may be life-threatening.

Investigation of the influencing factors with the uptake of the COVID-19 vaccine booster dose among the general population of Ardabil, Iran: A cross-sectional study.

Vaccination is one of the most efficient approaches to combating COVID-19 if it is adequately embraced by the general population. Numerous factors influence the uptake or refusal of the booster dose. The goal of this study was to look at the different factors that affect how the general population in Ardabil feels about getting vaccine boosters (annual boosters) for COVID-19 and to evaluate those feelings. In the city of Ardabil, general population, perceptions towards the COVID-19 vaccine booster (annual boosters) dose were evaluated using a cross-sectional survey design between January 2 and March 25, 2022. A questionnaire was developed and filled out by 662 subjects via phone calls from healthcare providers. Descriptive statistics, the Chi-square test, the correlation coefficient, and regression analysis were run for the analysis of quantitative data. The findings of the research revealed that 238 participants, or 35.9%, had previously gotten the booster dose of the COVID-19 vaccination, while 198 participants, or 29.2%, expressed a desire to do so as soon as feasible. A total of 187 (28.2%) respondents reported not wanting to get a booster dose, and 39 (5.7%) could not decide. In the factors found to affect decisions not to accept regular doses, adverse effects (45.4%) and the presence of misinformation (30%) were the most important. Regression in educational achievement, and following the COVID-19 news showed to be the major predictors of the subjects' attitudes toward the regular COVID-19 vaccine. The present findings revealed that low confidence in the efficiency of the booster shot and misinformation are two critical factors to consider in educational planning and interventions.

Willingness to pay for an annual vaccine in an endemic COVID-19 scenario: a contingent valuation study in Metro Manila, Philippines

Using the Contingent Valuation Method, this paper estimated willingness to pay (WTP) for annual COVID-19 booster vaccines for the endemic phase of the disease. The study found that, on the average, Metro Manila households would be WTP PhP2,199.71–2,410.50 (US$42.71–46.81) for a one-dose vaccine with 90% efficacy for one year. This WTP estimate is a measure of the perceived benefits from preventing COVID-19 infection, suggesting the potential for private markets to cater to those who prefer to obtain the annual booster COVID-19 vaccine privately, while a public vaccination program that subsidizes partially or fully the cost of the vaccine for those with lower capacity to pay is likely to pass a social cost–benefit assessment. Consistent with economic theory, WTP was found to significantly decrease with vaccine price and increase with income. Further, the study found general acceptance (measured in terms of the Health Benefit Model constructs) of COVID-19 vaccines among Metro Manila households despite the dengue vaccine controversy in the country immediately prior to the COVID-19 pandemic.

Attitudes toward annual COVID-19 boosters are highly structured by partisan self-identification and trust in government: Evidence from a longitudinal survey

ObjectivesOn January 26, 2023, an advisory panel of the United States Food and Drug Administration (FDA) approved a plan for annual vaccination for COVID-19. Given slowing booster uptake in the US, full participation of the public is in doubt. Using data from a longitudinal survey, we investigated the predictors of attitudes toward receiving a COVID-19 booster dose annually. Study designIn February 2023, we completed a panel study of 243 adults from South Dakota who indicated being at least fully vaccinated in a survey conducted in May 2022. MethodsIn addition to attitudes on an annual booster, we measured partisan self-identification, trust in government, interpersonal trust, COVID-19 vaccination status, age, gender, education, and income. We examined the effect of changes in COVID-19 vaccination status, and the two trust variables on the willingness to receive a COVID-19 booster dose annually. ResultsLogistic regression analysis results showed statistically significant relationships between partisan self-identification, changes in trust in government and COVID-19 vaccination status, age, and the willingness to receive a COVID-19 booster dose annually. ConclusionsThe findings underscore the continued relevance of partisan self-identification and trust in government on attitudes toward COVID-19 mitigation measures.

Chapter 14: TBE-Prevention: Vaccines and Immunoglobulins

Worldwide there are 6 different TBE vaccines – two from Western Europe, three from Russia and one from China. The two western European vaccines and one of the Russian vaccines have an adult and a pediatric formulation. The products names are FSME IMMUN and FSME-IMMUN Junior; Encepur adults and Encepur children, Klesch-E-Vac, EnceVir and EnceVir Neo, Dry lyophilized TBE Moscow and Sen Tai Bao All TBE vaccines except the one from China have similar but not identical immunization schedules with primary immunization (&gt;3 doses) and regular booster vaccinations. For FSME-IMMUN, Encepur and EnceVir rapid immunization schedules are also licensed. The Chinese vaccine is given with 2 primary doses 2 weeks apart followed by annual boosters. All vaccines induce significant immune responses. In the absence of a formal correlate of protection, the presence of neutralizing antibodies is used as a surrogate marker for protection. Recent clinical studies show long-term seropersistence of TBE antibodies after the first booster vaccination (dose 4) with the two European vaccines. An effectiveness of approximately 99% (years 2000–2006) and 98.7% (years 2000-2011) was calculated for regularly vaccinated persons in Austria, a country with established high vaccination uptake. Whereas in Western Europe post-exposure prophylaxis with immunoglobulins was discontinued in the late 1990s, in the highly endemic regions of Russia it continues to be common practice. Both – FSME-IMMUN and Encepur are well tolerated with a well-established safety profile. TBE-Moscow and EnceVir appear to be somewhat more reactogenic.

113 Leptospirosis vaccination and titer concentration testing in equine

Vaccines can help protect animals from diseases. Standard practice includes administering an initial vaccination followed by a booster a few weeks later, and then annual boosters thereafter. However, boosters may not be needed each year if immunity lasts longer. Titer concentration, which evaluates antibodies in blood, may be helpful in determining immune response and estimating protected status after vaccination. Leptospirosis is a bacterial disease that can cause blindness and abortion in horses. There is one USDA approved vaccine available for Leptospirosis pomona (L. pomona), the serovar associated with most clinical cases in North America. However, there is limited research on how the immune system in horses responds to the vaccine, and what titer concentrations may result from vaccination. Thirty-seven university horses previously unvaccinated for L. pomona and with no medical history of uveitis or abortion were selected. Blood was drawn and evaluated for baseline leptospirosis titers. Horses were then divided into TRT (vaccinated, n = 20; all geldings; average age 16 yr) or CON (not vaccinated, n = 17; 8 mares, 9 geldings; average age 17 yr) groups, and TRT horses were vaccinated. Blood samples were again collected from all 37 horses 14 d post-vaccination. The TRT group received boosters 3 wk after the first vaccination, and blood samples were again collected from all 37 horses 14 d post-booster. Data were evaluated using 2-samplet-Tests assuming unequal variances. Baseline results showed a higher seroprevalence of L. pomona as compared with previously published research (n = 4 of 37, 10.8%, versus 4% and 1%). Titer concentration in positive horses ranged from 1:100 to 1:3200. Management aspects could have influenced this, as the university horses were more concentrated geographically than populations previously surveyed. There was no difference between TRT and CON at baseline (P = 0.313). There was a difference over time for TRT horses (P < 0.001), but no change in CON. As expected, TRT horses had higher titers at 14 d post-vaccination (CON versus TRT mean concentration 429 and 6221, respectively, P < 0.005) and 14 d post-booster (CON versus TRT mean concentration 224 and 3900 respectively, P < 0.001). Titer concentrations in TRT horses ranged from 1:200 to 1:25,600 post-vaccination and from 1:200 to 1:6400 post-booster. There was no difference in TRT titers between post-vaccination and post-booster (mean concentration 6221 and 3900, respectively, P = 0.158). Results showed that vaccination did promote immune response, but the wide range of titer concentrations suggest that a single assessment of titer may not be appropriate for assessing protected status.