Bacillus Calmette-Guérin (BCG) Revaccination and Protection Against Tuberculosis: A Systematic Review

Bacillus Calmette-Guérin (BCG) vaccination remains a cornerstone in global efforts to combat tuberculosis (TB), a persistent public health threat worldwide. The purpose of this systematic review is to find out how well BCG revaccination protects against TB. This systematic review synthesized recent studies investigating the efficacy of BCG vaccination in preventing TB infection and disease. A total of 15 relevant publications were identified through a comprehensive search across multiple databases, including Cochrane Library, PubMed, Medline, and Scopus. The inclusion criteria encompassed studies involving humans, written in English, and categorized as case-control, cohort, meta-analysis, or full-text. Studies were selected based on their relevance to BCG revaccination and protection against TB, and a standardized data extraction form was used to gather pertinent information from each study. Quality assessment was conducted using established tools to evaluate the rigor, study design, and risk of bias in each included study. The findings revealed significant insights into BCG's effectiveness across different populations and age groups. Several studies demonstrated a substantial reduction in latent TB infection (LTBI) and incidence rates of TB following BCG vaccination. However, the protective efficacy of BCG revaccination varied across studies and populations, with some indicating modest protection against TB disease development, particularly in high-risk populations like healthcare workers. Furthermore, investigations into the immunological mechanisms underlying BCG's protective efficacy provided valuable insights into cytokine/chemokine profiles and immunomodulatory properties.

The safety of BCG revaccination in the context of COVID-19

The bacille Calmette-Guérin (BCG) vaccine is administered in many countries as part of their vaccination schedules. Epidemiologic studies have suggested a possible benefit of this vaccine in the context of the COVID-19 pandemic and other respiratory infections. We aimed to assess the safety of this intervention in BCG-primed adults. Adult health care workers (n = 451) received a single intradermal application of the BCG vaccine (Tokyo 172 strain) in the deltoid region of the right arm. Follow-up (30 days) calls and clinical inspections were guided using a standardized data sheet to assess local and systemic reactions. Early local reactions were common at 24 h and 7 days, such as erythema (74.9%, 69.2%), induration (55.7%, 59%), a papule (53.4%, 47.7%), and edema (48.3%, 38.1). Local symptoms (pruritus 44.8%, heat 16.2%, and pain 34.8%) were less frequent at day 7. Late expected reactions (14 and 30 days) included the formation of crusts (39.6% and 63.9%), a pustule (36.6% and 17%), or ulcers (28.8% and 17.7%). Severe reactions were limited to subcutaneous abscesses (2%) and lymphadenitis (<1%).

Safety of BCG vaccination and revaccination in healthcare workers

BCG vaccination and revaccination are increasingly being considered for the protection of adolescents and adults against tuberculosis and, more broadly, for the off-target protective immunological effects against other infectious and noninfectious diseases. Within an international randomized controlled trial of BCG vaccination in healthcare workers (the BRACE trial), we evaluated the incidence of local and serious adverse events, as well as the impact of previous BCG vaccination on local injection site reactions (BCG revaccination). Prospectively collected data from 99% (5351/5393) of participants in Australia, Brazil, Spain, The Netherlands and the UK was available for analysis. Most BCG recipients experienced the expected self-limiting local injection site reactions (pain, tenderness, erythema, swelling). BCG injection site itch was an additional common initial local symptom reported in 49% of BCG recipients. Compared to BCG vaccination in BCG-naïve individuals, BCG revaccination was associated with increased frequency of mild injection site reactions, as well as earlier onset and shorter duration of erythema and swelling, which were generally self-limiting. Injection site abscess and regional lymphadenopathy were the most common adverse events and had a benign course. Self-resolution occurred within a month in 80% of abscess cases and 100% of lymphadenopathy cases. At a time when BCG is being increasingly considered for its off-target effects, our findings indicate that BCG vaccination and revaccination have an acceptable safety profile in adults.

Antigenic Cartography Indicates That the Omicron BA.1 and BA.4/BA.5 Variants Remain Antigenically Distant to Ancestral SARS-CoV-2 after Sputnik V Vaccination Followed by Homologous (Sputnik V) or Heterologous (Comirnaty) Revaccination

The rapid emergence of evasive SARS-CoV-2 variants is an ongoing challenge for COVID-19 vaccinology. Traditional virus neutralization tests provide detailed datasets of neutralization titers against the viral variants. Such datasets are difficult to interpret and do not immediately inform of the sufficiency of the breadth of the antibody response. Some of these issues could be tackled using the antigenic cartography approach. In this study, we created antigenic maps using neutralization titers of sera from donors who received the Sputnik V booster vaccine after primary Sputnik V vaccination and compared them with the antigenic maps based on serum neutralization titers of Comirnaty-boosted donors. A traditional analysis of neutralization titers against the WT (wild-type), Alpha, Beta, Delta, Omicron BA.1, and BA.4/BA.5 variants showed a significant booster humoral response after both homologous (Sputnik V) and heterologous (Comirnaty) revaccinations against all of the studied viral variants. However, despite this, a more in-depth analysis using antigenic cartography revealed that Omicron variants remain antigenically distant from the WT, which is indicative of the formation of insufficient levels of cross-neutralizing antibodies. The implications of these findings may be significant when developing a new vaccine regimen.

Cost-effectiveness of future lockdown policies against the COVID-19 pandemic

AIM

While the European Union (EU) has approved several COVID-19 vaccines, new variants of concern may be able to escape immunity. The purpose of this study is to project the cost-effectiveness of future lockdown policies in conjunction with a variant-adapted vaccine booster. The exemplary scenario foresees a 25% decline in the vaccine protection against severe disease.

METHODS

A decision model was constructed using, for example, information on age-specific fatality rates, intensive care unit (ICU) costs and outcomes, and herd protection threshold. The costs and benefits of a future lockdown strategy were determined from a societal viewpoint under three future scenarios-a booster shot's efficacy of 0%, 50%, and 95%.

RESULTS

The cost-effectiveness ratio of a lockdown policy in conjunction with a booster dose with 95% efficacy is €44,214 per life year gained. A lockdown is cost-effective when the probability of approving a booster dose with 95% efficacy is at least 48% (76% when considering uncertainty in input factors).

CONCLUSION

In this exemplary scenario, a future lockdown policy appears to be cost-effective if the probability of approving a variant-adapted vaccine booster with an efficacy of 95% is at least 48%.

Seroconversion and antibody persistence after yellow fever vaccination in people living with HIV: impact of baseline HIV viral load and yellow fever seropositivity

BACKGROUND

Data on seroconversion rates following yellow fever (YF) vaccine and effect of revaccination in people living with HIV (PLWH) are scarce. We aimed at determining key factors for seroconversion after YF vaccine in PLWH and the role of preexisting neutralizing antibodies (NAbs) at vaccination.

METHODS

A retrospective cross-sectional study at several timepoints in two Belgian AIDS Reference Center. For each individual, plasma samples from three timepoints were selected: Timepoint 0 (TP0) in the year before administration of the YF vaccine, Timepoint 1 (TP1) in the year following the YF vaccine, Timepoint 2 (TP2) >1 year after the YF vaccine. Plasma samples were analysed for YF NAbs by plaque reduction neutralization test. The primary endpoint was the number of patients with protective levels of NAbs ≥ 1/10. A boosted immune response was defined as a 4-fold increase in serologic titres following revaccination.

RESULTS

Of the 160 PLWH included, protective levels of NAbs were present in 36%, 87% and 72% of subjects at baseline, at a median of 12 months and a median of 96 months after YF vaccination, respectively. Among vaccine recipients negative for YF NAbs at baseline (n = 102), 83% seroconverted. PLWH with undetectable HIV viral load (VL) at baseline were more likely to seroconvert (P < 0·01). A booster response was observed in only 17% of subjects with baseline seropositivity (n = 10 out of 58). In multivariate analysis, undetectable HIV VL at vaccination and baseline YF seropositivity were associated with persistent levels of protective NAbs at a median of 8 years after YF vaccination.

CONCLUSION

Undetectable HIV VL at baseline is associated with high rates of seroconversion. YF seropositivity before revaccination is associated with low rates of booster effect but a higher chance of long term persistent NAbs response, suggesting a benefit of revaccination in PLWH.

Experience of Military Medicine in the Fight against the New Coronavirus Infection

The results achieved by the medical service of the Armed Forces of the Russian Federation to overcome the new coronavirus infection are presented. The high efficiency of the established unified system of biological safety and strict ranking of the priorities of anti-epidemic measures is shown. The experience of organizing traveling medical and nursing teams, as well as temporary military medical units on the territory of Russia, as well as in foreign countries, is demonstrated. Among the priority scientific results of military doctors, especially noteworthy is the study of the world's first COVID-19 vaccine Sputnik V, its immunogenicity, the effectiveness of its use in previously ill patients and revaccination, as well as the use of immune plasma from those who have been ill and vaccinated. By the examples of organized military groups and the general population, the features of the formation of herd immunity have been studied. Military doctors were the first in the country to show the effectiveness of hormone therapy in the treatment of coronavirus infection and to study its effects. They carried out ultrastructural studies of the life cycle of the virus. It is shown that the system of comprehensive measures implemented by military medicine determined a lower incidence of new coronavirus infection among the personnel of the Ministry of Defense of Russia and a lower mortality among the military.

SARS-CoV-2 Vaccine-induced Thyroiditis: Safety of Revaccinations and Clinical Follow-up

CONTEXT

The number of reported cases with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) vaccine-induced subacute thyroiditis (SAT) and Graves' disease (GD) is growing. However, active debate continues about managing such side effects and the safety of repeat or booster doses of the vaccines in such cases.

OBJECTIVES

This study aims to present long-term clinical follow-up of SARS-CoV-2 vaccine-induced SAT or GD cases and provide data regarding the safety of revaccinations.

METHODS

Patients diagnosed with SARS-CoV-2 vaccine-induced SAT or GD were included. Data regarding the long-term clinical follow-up of SARS-CoV-2 vaccine-induced SAT and GD cases and outcomes of repeat or booster SARS-CoV-2 vaccinations were documented. The literature, including cases of SARS-CoV-2 vaccine-induced SAT or GD, was reviewed.

RESULTS

Fifteen patients with SARS-CoV-2 vaccine-induced SAT and 4 with GD were included. Pfizer/BioNTech COVID-19 vaccine (BNT162b2) was associated with symptoms in a majority of cases with SAT and all with GD. Median time from vaccination to symptom onset was 7 and 11.5 days, respectively, while 7 and 2 patients required medical treatment in SAT and GD groups, respectively. Remission was documented in 10 SAT patients, with a median time to remission of 11.5 weeks. No exacerbation/recurrence of SAT occurred in 7 of 9 patients who received a repeat vaccination dose, while symptoms of SAT worsened following the second vaccination in 2 cases. None of the patients experienced severe side effects that could be associated with revaccinations.

CONCLUSIONS

Revaccinations appear to be safe in patients with SARS-CoV-2 vaccine-induced SAT cases, while more evidence is needed regarding SARS-CoV-2 vaccine-induced GD.

12 Months Persistent Immunogenicity after Hepatitis B Vaccination in Patients with Type 2 Diabetes and Immunogenicity of Revaccination in Non-Responders: An Open-Label Randomized Controlled Trial

BACKGROUND

In initial studies, the immunogenicity and safety of hepatitis B vaccines in patients with diabetes has been assessed in China.

METHODS

In six township health centers in Gansu Province, 232 diabetic patients and 77 healthy people were allocated to receive two 3-dose hepatitis B vaccines (Group D20SC 0-1-6; Group D20CHO 0-1-6; Group ND20SC 0-1-6). Participants were followed up at 12 months after being fully vaccinated. One dose of the vaccine was randomly administered to non-responders. Chi-square test was used to compare the differences in response rate between two groups.

RESULTS

The anti-HBs response rates of three groups decreased from 84.1%, 89.1% and 88.3% at one month to 64.6%, 79.8% and 71.4% at twelve months. There was no statistical difference in the immune response rates between Group D20SC 0-1-6 and Group ND20SC 0-1-6; however, that of Group D20CHO 0-1-6 was higher than that of Group D20SC 0-1-6. After revaccination, the geometric mean concentrations were 491.7 mIU/mL and 29.7 mIU/mL after using vaccines containing 60 μg and 20 μg HBsAg.

CONCLUSIONS

At 12 months, immune response in diabetic patients were not significantly different from that in healthy people. Revaccination with one dose of hepatitis B vaccine containing 60 μg HBsAg for non-responders was more satisfactory.

Patients with suspected allergic reactions to COVID-19 vaccines can be safely revaccinated after diagnostic work-up

BACKGROUND

When initiating the Danish vaccination program against COVID-19, the incidence of anaphylaxis was estimated to be 10 times higher compared to other virus-based vaccines. In this study, we present data on patients referred with suspected allergic reactions to COVID-19 vaccines. The main purpose of the study is to investigate the incidence and severity of the allergic reactions, and to evaluate the safety of revaccination.

METHODS

All patients in the region of Southern Denmark with case histories of allergic reactions to COVID-19 vaccines in a defined period are included in this study. Diagnostic work up consisted of a detailed case history, evaluation of Brighton level of diagnostic certainty and World Allergy Organization grade of anaphylaxis and skin prick testing- and basophil histamine release testing with COVID-19 vaccines and relevant drug excipients. Patients were revaccinated at the Allergy Center when possible.

RESULTS

Sixty-one patients are included in this study. In 199,377 doses administered, nine patients fulfilled the criteria of anaphylaxis when using the Brighton Criteria (incidence being 45 per million). Of 55 patients with reactions to the first dose, 52 patients were revaccinated without adverse reactions. We found no proven cases of immediate anaphylaxis due to COVID-19 vaccines. By skin prick test, we diagnosed three patients with drug excipient allergy and further a patient with mastocytosis was found.

CONCLUSIONS

Anaphylactic reactions to COVID-19 vaccines are rare and the incidence is similar to what is seen with other virus-based vaccines. Revaccination is safe in the majority of patients; however, allergological evaluation is important since some prove to have drug excipient allergy.

A century of BCG: Impact on tuberculosis control and beyond

BCG turns 100 this year and while it might not be the perfect vaccine, it has certainly contributed significantly towards eradication and prevention of spread of tuberculosis (TB). The search for newer and better vaccines for TB is an ongoing endeavor and latest results from trials of candidate TB vaccines such as M72AS01 look promising. However, recent encouraging data from BCG revaccination trials in adults combined with studies on mucosal and intravenous routes of BCG vaccination in non-human primate models have renewed interest in BCG for TB prevention. In addition, several well-demonstrated non-specific effects of BCG, for example, prevention of viral and respiratory infections, give BCG an added advantage. Also, BCG vaccination is currently being widely tested in human clinical trials to determine whether it protects against SARS-CoV-2 infection and/or death with detailed analyses and outcomes from several ongoing trials across the world awaited. Through this review, we attempt to bring together information on various aspects of the BCG-induced immune response, its efficacy in TB control, comparison with other candidate TB vaccines and strategies to improve its efficiency including revaccination and alternate routes of administration. Finally, we discuss the future relevance of BCG use especially in light of its several heterologous benefits.

Immunogenicity following revaccination or sequential vaccination with 23-valent pneumococcal polysaccharide vaccine (PPSV23) in older adults and those at increased risk of pneumococcal disease: a review of the literature

Introduction: Immunogenicity studies evaluating sequential administration of pneumococcal conjugate vaccine (PCV) followed by 23-valent pneumococcal polysaccharide vaccine (PPSV23) or revaccination with PPSV23 have raised concerns that PPSV23 may not elicit higher antibody levels than those measured following PCV or first PPSV23 dose.Areas covered: Recent literature was evaluated for evidence of blunted immune response (hyporesponsiveness), focusing on studies using adequate intervals between doses in accordance with vaccination recommendations. In eight of nine studies that evaluated revaccination with PPSV23 at an interval of ≥5 years after the previous dose, immunoglobulin G geometric mean concentrations and/or opsonophagocytic assay geometric mean titers for most serotypes increased from pre- to post-repeat vaccination and were comparable between repeat and primary vaccination groups post-vaccination. In seven studies in which PPSV23 was administered after PCVs (8 weeks to 1 year apart), responses to PPSV23 were comparable to those seen after initial PCV dose for shared vaccine serotypes. Studies in which PCVs were administered after PPSV23 were not evaluated.Expert opinion: Published data suggest immune responses following repeat vaccination with PPSV23, or sequential PCV/PPSV23 vaccination, are robust, without evidence of hyporesponsiveness. PPSV23 vaccination of at-risk adults is essential to ensure broad protection against all 23 vaccine serotypes.

Immunogenicity and Protection against Mycobacterium caprae Challenge in Goats Vaccinated with BCG and Revaccinated after One Year

Vaccination has been proposed as a supplementary tool for the control of tuberculosis in livestock. The long-term immunogenicity elicited by bacillus Calmette–Guerin (BCG) and the efficacy of revaccination were investigated in thirty goat kids distributed into three groups: unvaccinated controls, BCG (vaccinated at week 0) and BCG-BCG (vaccinated at weeks 0 and 56). Sixty-four weeks after the first vaccination, all animals were challenged with Mycobacterium caprae and examined post-mortem (pathology and bacterial load) at week 73. Antigen-specific interferon-gamma (IFN-γ) release was measured throughout the experiment. At week 59, peripheral blood mononuclear cells were stained for CD4, CD45RO and IFN-γ to determine the presence of antigen-specific cells secreting IFN-γ. The BCG-BCG group showed reductions in rectal temperatures, M. caprae DNA load in pulmonary lymph nodes (LN), the volume of lesions in pulmonary LN, mineralization in lungs, and higher weight gains compared to unvaccinated controls. IFN-γ responses were undetectable from 32 weeks after primary vaccination until revaccination, when the BCG-BCG group showed detectable IFN-γ production and a greater percentage of antigen-specific CD4⁺CD45RO⁺IFNγ⁺ and CD4⁻CD45RO⁺IFNγ⁺ cells compared to the BCG and control groups, which may be an indicator of the mechanisms of protection. Thus, re-vaccination of goats with BCG appears to prolong protection against infection with M. caprae.

Redefining Non-Inferiority in Anamnestic Antibody Responses Using the Mean Increase of Log-Transformed Antibody Titers after Revaccination: Secondary Analysis of a Randomized Controlled Rabies Vaccination Trial

Non-inferiority in the anamnestic antibody response is conventionally determined by comparing seroconversion rates after revaccination. However, this approach is inadequate in the case of high pre-booster antibody titers. Therefore, we propose an alternative method to determine non-inferiority of booster responses. We used anonymized data from a randomized controlled trial (NCT01388985; EudraCT 2011-001612-62) in 500 adults, comparing a two-visit primary vaccination schedule (two intradermal 0.1 mL rabies vaccine doses on day 0 and 7) with a three-visit schedule (single intradermal 0.1 mL dose on day 0, 7, and 28). Participants were revaccinated intradermally (single dose) 1 to 3 years later. Rabies virus neutralizing antibody titers were measured on day 0 and 7 after revaccination. After log₃-transformation of antibody titers, the mean increase in titers after revaccination was compared between schedules. Non-inferiority was defined as the lower bound of the two-sided 95% confidence interval not exceeding -0.369. Four hundred and ten participants fulfilled the inclusion criteria. The mean increase in log₃ titer was 2.21 and 2.31 for the two-visit and three-visit schedule, respectively. The difference between these increases was -0.10 [-0.28, 0.08], meeting the non-inferiority criterion. In conclusion, comparing mean increases in log-transformed titers after revaccination appears to be a feasible and more informative method of studying non-inferiority regarding the anamnestic antibody response.

Treatment and revaccination of children with paraneoplastic opsoclonus-myoclonus-ataxia syndrome and neuroblastoma: The Memorial Sloan Kettering experience

OBJECTIVE

To review the treatment and revaccination of neuroblastoma-associated opsoclonus-myoclonus-ataxia syndrome (OMAS) patients at Memorial Sloan Kettering Cancer Center (MSK).

PROCEDURE

Institutional Review Board approval was obtained for this retrospective study of patients with neuroblastoma-associated OMAS followed at MSK from 2000 to 2016.

RESULTS

Fourteen patients (nine female) were 9-21 (median 17) months old at diagnosis of neuroblastoma and OMAS syndrome. They had stage 1 (n = 12), stage 2B, or intermediate-risk stage 4. Tumor histology was favorable in 11 patients, unfavorable in two, and unknown in one patient. No patient had amplified MYCN. All patients underwent tumor resection at diagnosis. Anti-neuroblastoma treatment was limited to chemotherapy in one patient. Overall survival is 100% at 3-16 (median 10) years. For OMAS, 13 patients received intravenous immune globulin (IVIg), adrenocorticotropic hormone (ACTH), and rituximab, and one received ACTH and IVIg. Seven patients experienced OMAS relapse. For these relapses, five patients received low-dose cyclophosphamide and two received rituximab. The mean total OMAS treatment was 20-96 (median 48) months. Seven patients started rituximab ≤3 months from diagnosis and did not relapse. The other six experienced OMAS relapse. To date, six patients have been revaccinated at a minimum of 2 years after completion of OMAS therapy without OMAS recurrence.

CONCLUSIONS

Patients with neuroblastoma-associated OMAS had excellent overall survival. Early initiation of rituximab, IVIg, and ACTH may reduce risks of OMAS relapse. Revaccination can be resumed without exacerbation of OMAS. Further investigation with a larger cohort of patients is needed.

Vaccinations and Immune Response in Celiac Disease

Immune response to vaccinations in celiac patients is of growing scientific interest. However, some aspects of the relationship between celiac disease (CD) and vaccines are still unclear. A comprehensive search of published literature using the PubMed database was carried out using the following key terms: "adaptive immunity", "celiac disease", "humoral immune response", "immunization", and "vaccination". To date, there is no evidence showing any causative association between vaccines and CD development. Therefore, vaccinations may be administered according to the modalities and timing of the National Immunization Schedule for each country. The rotavirus vaccine is currently recommended for the general population, and according to some data, it appears to reduce the risk for the development of CD autoimmunity in the early years of life. Regarding the hepatitis B virus, a booster dose of the vaccine is often required due to the low or the lost immune response rate in CD. Furthermore, determination of hepatitis B antibody titers could be useful in newly diagnosed CD subjects regardless of age at diagnosis. Finally, pneumococcal vaccines may be administered in patients with advancing age at diagnosis and concomitant risk factors. Future clinical practice guidelines for vaccination and monitoring programs in celiac patients could be recommended.

Cost-effectiveness of an adjuvanted recombinant zoster vaccine in older adults in the United States who have been previously vaccinated with zoster vaccine live

Zoster Vaccine Live (ZVL) is marketed in the US since 2008, and a non-live adjuvanted Recombinant Zoster Vaccine (RZV) was approved in 2017. Literature suggests that waning of ZVL efficacy may necessitate additional vaccination. The Advisory Committee on Immunization Practices recommended vaccination with RZV in immunocompetent adults aged 50+ years old, including those previously vaccinated with ZVL. The objective of this study was to determine the cost-effectiveness of vaccinating US adults aged 60+ years old, previously vaccinated with ZVL. The ZOster ecoNomic Analysis (ZONA) model, a deterministic Markov model, was adapted to follow a hypothetical 1 million(M)-person cohort of US adults previously vaccinated with ZVL. Model inputs included demographics, epidemiology, vaccine characteristics, utilities and costs. Costs and quality-adjusted life-years (QALYs) were presented over the lifetimes of the cohort from the year of additional vaccination, discounted 3% annually. The model estimated that, vaccination with RZV 5 years after previous vaccination with ZVL, would reduce disease burden compared with no additional vaccination, resulting in a gain of 1,633 QALYs at a total societal cost of $96M (incremental cost-effectiveness ratio: $58,793/QALY saved). Compared with revaccinating with ZVL, vaccination with RZV would result in a gain of 1,187 QALYs and societal cost savings of almost $84M. Sensitivity, scenario, and threshold analyses demonstrated robustness of these findings. Vaccination with RZV is predicted to be cost-effective relative to no additional vaccination, assuming a threshold of $100,000/QALY, and cost-saving relative to ZVL revaccination of US adults aged 60+ years old who have been previously vaccinated with ZVL.

A cost-effectiveness analysis of revaccination and catch-up strategies with the 23-valent pneumococcal polysaccharide vaccine (PPV23) in older adults in Japan

OBJECTIVE

In Japan, the National Immunization Program (NIP) includes PPV23 as the primary vaccination for adults and catch-up cohorts. The Japanese Association for Infectious Diseases recommends revaccination for older adults who received primary vaccination ≥5 years earlier. The cost-effectiveness of adding revaccination and/or continuing catch-up vaccination in the NIP was evaluated from the public payer perspective in Japan.

METHODS

The Markov model included five health states: no pneumococcal disease, invasive pneumococcal diseases (IPD), non-bacteremic pneumococcal pneumonia (NBPP), post-meningitis sequelae, and death. Cohorts of adults aged 65-95 were followed until age 100 or death: 2014 cohort (aged 65-95, vaccinated: 2014); 2019 cohort (aged 65: 2019); and 2019 catch-up cohort (aged 70-100: 2019, unvaccinated: 2014). Strategies included: (1) vaccinate 2014 and 2019 cohorts; (2) vaccinate 2014 and 2019 cohorts and revaccinate both; (3) strategy 1 and vaccinate 2019 catch-up cohort; (4) strategy 2 and vaccinate 2019 catch-up cohort; and (5) strategy 4 and revaccinate 2019 catch-up cohort. Parameters were retrieved from global and Japanese sources, costs and QALYs discounted at 2%, and incremental cost-effectiveness ratios (ICERs) estimated.

RESULTS

Strategy 1 had the highest number of IPD and NBPP cases, and strategy 5 the lowest. Strategies 3-5 dominated strategy 1 and strategy 2 was cost-effective compared to strategy 1 (ICER: ¥1,622,153 per QALY gained). At a willingness-to-pay threshold of ¥5 million per QALY gained, strategy 2 was cost-effective and strategies 3-5 were cost-saving compared to strategy 1.

CONCLUSIONS

Strategies including revaccination, catch-up, or both were cost-effective or cost-saving in comparison to no revaccination and no catch-up. Results can inform future vaccine policies and programs in Japan.

Time interval of revaccination with 23-valent pneumococcal polysaccharide vaccine more than 5 years does not affect the immunogenicity and safety in the Japanese elderly

In the previous study, revaccination with 23-valent pneumococcal polysaccharide vaccine (PPSV23) in a total of 161 elderly subjects (≥70 years of age) who had received the initial vaccination at least 5 years before (range: 5 to11 years) showed an acceptable safety profile and induction of immune responses to the serotypes in PPSV23. The optimal interval between the initial vaccination and revaccination with PPSV23 is of interest to protect elderly from pneumococcal disease over the long-term. In this post-hoc analysis, we analyzed that the immunogenicity and safety of revaccination with PPSV23 by time interval after the initial vaccination. The level of serotype-specific immunoglobulin G (IgG) geometric mean concentrations (GMCs) and opsonophagocytic killing activity (OPA) geometric mean titers (GMTs) at 4 weeks after revaccination with PPSV23 in each subgroup based on time interval (5, 6, 7, 8 and 9-11 years) after the initial vaccination were comparable to those after the primary vaccination and vaccine-induced serotype-specific IgG and OPA levels were similar regardless of the time interval after the initial vaccination. There was no difference in the safety profiles among the subgroups. In conclusion, administration of a second dose of PPSV23 at least 5 years after the initial vaccination was immunogenic and well-tolerated in the elderly ≥70 years of age regardless of the time interval after the initial vaccination.

Adherence and immune response to revaccination following hematopoietic stem cell transplantation at a pediatric onco-hematology reference center

BACKGROUND

Revaccination after hematopoietic stem cell transplantation (HSCT) is necessary to compensate for the loss of immunological memory. The aims of this study were to evaluate the adherence to revaccination schedule and the humoral immune response to different vaccine antigens in HSCT pediatric and young adult patients.

METHODS

Patients submitted to HSCT for over 3 years were recruited. After written informed consent, a questionnaire was filled in, the vaccination card was analyzed, a blood sample was collected and tested by ELISA for diphtheria, Haemophilus influenzae type b (Hib), hepatitis A, hepatitis B, tetanus, measles, rubella, and varicella antibodies.

RESULTS

Sixty-three patients (mean age at HSCT, 10.7 years) were evaluated. Forty-one (65%) were male; 34 (54%) had allogeneic and 29 (46%), autologous HSCT. Complete adherence to diphtheria revaccination was found in 79.4% patients and seropositivity was found in 92% of those who completed the revaccination schedule; for Hib, 68.3% adherence and 95.3% seropositivity were observed; for hepatitis A, 63.5% adherence and 92.5% seropositivity; for 3 doses of hepatitis B, 86.8% adherence and 79.2% seropositivity; for tetanus, 79.4% adherence and 100% seropositivity; for measles and rubella, 17.5% adherence and 100% seropositivity; for varicella, 7.9% adherence and 100% seropositivity. The existence of a Vaccination Center for Special Immunobiologicals in patients' municipality was positively associated with completed vaccine schedule; on the other hand, chronic GVHD was negatively associated with revaccination adherence.

CONCLUSION

Hematopoietic stem cell transplantation patients showed good seropositivity rates after complete vaccination schedule. However, a low coverage rate was observed for live attenuated antigens.

Cost Analysis of Single-Dose Hepatitis B Revaccination Among Infants Born to Hepatitis B Surface Antigen-Positive Mothers and Not Responding to the Initial Vaccine Series

OBJECTIVES

Infants born to mothers who are hepatitis B surface antigen (HBsAg) positive are at risk for perinatal hepatitis B infection. As prevention, these infants receive a series of 3 or 4 doses of hepatitis B vaccine starting at birth and postvaccination serologic testing. Infants with antibody levels <10 mIU/mL are considered vaccine nonresponders and should be revaccinated. The objective of this cost analysis was to assess a single-dose revaccination strategy among infant nonresponders.

METHODS

We used a decision analytic tree to compare the costs of a single-dose revaccination strategy with the costs of a 3-dose revaccination strategy. The analysis consisted of 3 epidemiologic scenarios that varied levels of previous protection among infants indicated for revaccination. We assumed health outcomes in each strategy were the same, and we evaluated costs from the societal perspective using 2016 US dollars. We conducted sensitivity analyses on key variables, including the minimum required efficacy of a single revaccination dose.

RESULTS

In all analyses, the single-dose revaccination strategy was a lower-cost option than the 3-dose revaccination strategy. Under the assumption that all revaccination visits were previously unscheduled, single-dose revaccination reduced the cost per infant by $119.81 to $155.72 (depending on the scenario). Across all scenarios, the most conservative estimate for the threshold efficacy (the minimum efficacy required to result in a lower-cost option) value of single-dose revaccination was 67%.

CONCLUSIONS

For infants who were born to HBsAg-positive mothers and who were not responding to the initial vaccine series, a single-dose revaccination strategy, compared with a 3-dose revaccination strategy, reduced costs across several scenarios. These results helped inform the Advisory Committee on Immunization Practices' vote in February 2017 to recommend single-dose revaccination.

Frequency and Cost of Vaccinations Administered Outside Minimum and Maximum Recommended Ages-2014 Data From 6 Sentinel Sites of Immunization Information Systems

OBJECTIVE

To quantify vaccinations administered outside minimum and maximum recommended ages and to determine attendant costs of revaccination by analyzing immunization information system (IIS) records.

STUDY DESIGN

We analyzed deidentified records of doses administered during 2014 to persons aged <18 years within 6 IIS sentinel sites (10% of the US population). We quantified doses administered outside of recommended ages according to the Advisory Committee on Immunization Practices childhood immunization schedule and prescribing information in package inserts, and calculated revaccination costs. To minimize misreporting bias, we analyzed publicly funded doses for which reported lot numbers and vaccine types were consistent.

RESULTS

Among 3 394 047 doses with maximum age recommendations, 9755 (0.3%) were given after the maximum age. One type of maximum age violation required revaccination: 1344 (0.7%) of 194 934 doses of the 0.25-mL prefilled syringe formulation of quadrivalent inactivated influenza vaccine (Fluzone Quadrivalent, Sanofi Pasteur, Swiftwater, PA) were administered at age ≥36 months (revaccination cost, $111 964). We identified a total of 7 529 165 childhood, adolescent, and lifespan doses with minimum age recommendations, 9542 of which (0.1%) were administered before the minimum age. The most common among these violations were quadrivalent injectable influenza vaccines (3835, or 0.7% of 526 110 doses administered before age 36 months) and Kinrix (GlaxoSmithKline Biologicals, Rixensart, Belgium; DTaP-IPV) (2509, or 1.2% of 208 218 doses administered before age 48 months). The cost of revaccination for minimum age violations (where recommended) was $179 179.

CONCLUSION

Administration of vaccines outside recommended minimum and maximum ages is rare, reflecting a general adherence to recommendations. Error rates were higher for several vaccines, some requiring revaccination. Vaccine schedule complexity and confusion among similar products might contribute to errors. Minimization of errors reduces wastage, excess cost, and inconvenience for parents and patients.

Ultra-short-course booster is effective in recurrent grass pollen-induced allergic rhinoconjunctivitis

Background

A relevant proportion of allergic rhinoconjunctivitis (ARC) patients experience recurrent symptoms after successfully completing allergen immunotherapy (AIT). This prospective, controlled, noninterventional study used internationally standardized instruments to determine the clinical effects of a preseasonal, ultra‐short‐course booster AIT on clinical outcome parameters.

Methods

This two‐arm study included patients aged ≥12 years with recurrent grass pollen‐induced seasonal AR who had completed a successful course of any grass pollen AIT at least 5 years before enrolment. Overall, 56 patients received one preseasonal short‐course booster AIT using tyrosine‐absorbed grass pollen allergoids containing the adjuvant monophosphoryl lipid A (MPL^®); 51 control patients received symptomatic medication. The combined symptom and medication score (CSMS) was recorded in the (peak) grass pollen season. Furthermore, concomitant (antiallergic) medication use, the patients’ state of health, Mini Rhinoconjunctivitis Quality of Life Questionnaire (MiniRQLQ) results and safety/tolerability of the treatment were assessed.

Results

The CSMS in the peak grass pollen season was significantly lower in the booster AIT group (Δ=38.4%, P<.01). Moreover, significantly more patients in this group used no concomitant antiallergic medication throughout the peak grass pollen season. Twice as many patients in the booster AIT group as in the control group reported having a better state of health than in the preceding season. MiniRQLQ results showed significant differences favouring the booster AIT. The booster AIT was generally well tolerated, with only two patients reporting mild, grade 1 systemic adverse events.

Conclusion

Booster AIT using tyrosine‐absorbed allergoids containing the adjuvant MPL^® effectively prevents re‐occurrence of symptoms in patients with grass pollen‐induced ARC.

Immunogenicity and Safety of the HZ/su Adjuvanted Herpes Zoster Subunit Vaccine in Adults Previously Vaccinated With a Live Attenuated Herpes Zoster Vaccine

Background

Protection against herpes zoster (HZ) induced by the live attenuated zoster vaccine Zostavax (ZVL) wanes within 3–7 years. Revaccination may renew protection. We assessed whether (re)vaccination with the adjuvanted HZ subunit vaccine candidate (HZ/su) induced comparable immune responses in previous ZVL recipients and ZVL-naive individuals (HZ-NonVac).

Methods

In an open-label, multicenter study, adults ≥65 years of age, vaccinated with ZVL ≥5 years previously (HZ-PreVac), were matched to ZVL-naive adults (HZ-NonVac). Participants received 2 doses of HZ/su 2 months apart. The primary objective of noninferiority of the humoral immune response 1 month post–dose 2 was considered demonstrated if the upper limit of the 95% confidence interval (CI) of the adjusted anti–glycoprotein E geometric mean concentration (GMC) ratio of HZ-NonVac over HZ-PreVac was <1.5. HZ/su cellular immunogenicity, reactogenicity, and safety were also assessed.

Results

In 430 participants, humoral immune response to HZ/su was noninferior in HZ-PreVac compared with HZ-NonVac (adjusted GMC ratio, 1.04 [95% CI, .92–1.17]). Cellular immunogenicity, reactogenicity, and safety appeared to be comparable between groups. HZ/su was well-tolerated, with no safety concerns raised within 1 month post–dose 2.

Conclusions

HZ/su induces a strong immune response irrespective of prior vaccination with ZVL, and may be an attractive option to revaccinate prior ZVL recipients.

Clinical Trials Registration

NCT02581410.

A systematic review of the efficacy of live attenuated influenza vaccine upon revaccination of children

Four randomized, double-blind, placebo-controlled studies in 6090 children that investigated the efficacy of live attenuated influenza vaccine (LAIV) upon revaccination of children against laboratory-confirmed cases of influenza in consecutive seasons were reviewed. The efficacy in season 2 of LAIV administered over 2 consecutive seasons was 86.7% (95 % CI: 76.8%, 92.4%) against strains antigenically similar to those contained in the vaccine. The additional efficacy of LAIV administered in season 2 compared to LAIV recipients in season 1 only was 58.4% (28.3%, 75.9%). LAIV administered over 2 consecutive seasons also was more efficacious than was LAIV administered in season 2 only (relative efficacy: 53.9% [17.4%, 74.3%]). Residual efficacy of LAIV administered in season 1 only compared to placebo administered in two consecutive seasons was 56.4% (37.0%, 69.8%). This review did not find any evidence of decreasing efficacy of LAIV when administered during 2 consecutive seasons.

Influenza vaccination in children primed with MF59-adjuvanted or non-adjuvanted seasonal influenza vaccine

Routine annual influenza immunization is increasingly recommended in young children. We compared the safety and immunogenicity of vaccination with trivalent inactivated influenza vaccine (TIV) versus MF59-adjuvanted TIV (aTIV) in children who received 2 half or full doses of aTIV or TIV, or non-influenza control vaccine, in an efficacy trial conducted 2 years earlier. 197 healthy children aged 30-96 months were randomized to receive vaccination with aTIV or TIV in 2010. To evaluate responses to the first follow-up seasonal vaccination after priming we excluded children who received influenza vaccine(s) in the 2009 pandemic year leaving 40 children vaccinated with aTIV, 26 children with TIV and 10 children with aTIV after a control vaccine in the parent study. Hemagglutination inhibiting antibodies were assayed on Days 1, 22 and 181. aTIV vaccination produced 6.9 to 8.0-fold higher antibody responses than the reference TIV-TIV regimen against A/H3N2 and B strains, which remained higher 6 months following vaccination. The response to the B/Victoria lineage antigen in the second year's vaccine (the first vaccine contained a B/Yamagata lineage antigen) demonstrated that aTIV primed for an adequate response after a single dose on Day 22 (GMTs 160, 95 to antigens in the 2 lineages, respectively), whereas TIV did not (GMTs 38, 20). Vaccination with aTIV produced slightly higher but acceptable local and systemic reactogenicity compared to TIV-TIV and TIV-aTIV mixed regimens. Within the limitations of a small study, the strong immune responses support the use of aTIV for vaccination in young children.

Substantial variation in post-engraftment infection prophylaxis and revaccination practice in autologous stem cell transplant patients

There is a paucity of evidence supporting the necessity or duration of Pneumocystis jirovecii and antiviral prophylaxis as well as revaccination following autologous stem cell transplant (ASCT). A survey aimed at evaluating these policies was distributed to 34 ASCT centres across Australasia. The 26 survey respondents demonstrated significant heterogeneity in their infection prophylaxis and revaccination strategy post-transplant despite the availability of consensual guidelines.

Antibody response to revaccination among adult non-responders to primary Hepatitis B vaccination in China

About 10% adult failed to develop antibody response after primary hepatitis B vaccination, and revaccination may be an option to improve immune response, but the antibody responses to revaccination in adult non-responders have not been fully examined. Adult non-responders to primary 3-dose hepatitis B vaccination were randomly divided into 2 groups and revaccinated with 20 μg hepatitis B vaccine (HepB) derived from Saccharomyces Cerevisiae (HepB-SC) or 20 μg HepB derived from Chinese hamster ovary cells (HepB-CHO), respectively, at 0-, 1-, 6- month. Seroconversion rate and titer of antibody against hepatitis B surface antigen (anti-HBs) was measured one month after the 1st and 3rd revaccination dose. Anti-HBs seroconversion rates significantly increased from 54.98% [95% confidence interval (CI) 48.60%-61.24%] after the 1st revaccination dose to 89.24% (95% CI: 84.74%-92.79%) after the 3rd revaccination dose (P < 0.001), and the geometric mean titer (GMT) of anti-HBs increased from 12.18 mIU/ml (95%CI: 7.81-18.98 mIU/ml) to 208.31 mIU/ml (95% CI: 148.87-291.47 mIU/ml) (P = 0.008).Compared with those with anti-HBs titer <2 mIU/ml after primary vaccination, those with antibody titer ≥ 2 mIU/ml after primary vaccination had higher seroconversion rate after the 1st dose revaccination (38.36% vs. 78.10%, P < 0.001) and after the 3rd dose of revaccination (84.25% vs. 96.19%, P = 0.003), and had higher antibody titer after the 1st dose of revaccination (3.32 mIU/ml vs. 74.21 mIU/ml, P < 0.0001) and after the 3rd dose of revaccination (145.73 mIU/ml vs. 342.34 mIU/ml, P = 0.01). Anti-HBs titer was significantly higher in those revaccinated with HepB-CHO than those revaccinated with HepB-SC after the 3rd dose (131.46 mIU/ml vs. 313.38 mIU/ml, P = 0.01). Revaccination on adult HepB non-responders increased the immune response to HepB and may confer further protection against hepatitis B virus infection. If possible, revaccination might be an option to HepB non-responders to secure more protection.

Hepatitis B revaccination in HIV-infected vaccine non-responders: is double dosing always necessary?

Limited data exist on hepatitis B revaccination strategies for HIV-infected individuals who do not develop immunity after the first vaccination series. A retrospective cohort study was conducted to assess the immunogenicity of the second series of hepatitis B vaccine given in standard dosing (SD) and double dosing (DD) strategies among Thai HIV-infected adults during the period from January 2006 to December 2014. Of the 120 eligible patients, 68 (57%) were men, median age was 38 years old, 87 (73%) received SD and 33 (27%) received DD revaccination. The demographic and clinical characteristics of SD and DD groups were comparable. The overall vaccine response rate was significantly higher in DD group than SD group (97% vs. 70%; p = 0.001). Independent factors associated with no response to hepatitis B revaccination were receipt of SD vaccine (adjusted odds ratio [aOR] 16.04; p = 0.009), age ≥ 40 years (aOR 3.66; p = 0.009) and CD4 cell count at the time of revaccination less than 450 cells/µL (aOR 2.96; p = 0.04). These findings suggest that DD hepatitis B revaccination series should be given in HIV-infected patients who were at least 40 years old or had CD4 counts less than 450 cells/µL after no response to the first vaccination series.

T cell anergy and activation are associated with suboptimal humoral responses to measles revaccination in HIV-infected children on anti-retroviral therapy in Nairobi, Kenya

HIV-infected children are less capable of mounting and maintaining protective humoral responses to vaccination against measles compared to HIV-uninfected children. This poses a public health challenge in countries with high HIV burdens. Administration of anti-retroviral therapy (ART) and revaccinating children against measles is one approach to increase measles immunity in HIV-infected children, yet it is not effective in all cases. Immune anergy and activation during HIV infection are factors that could influence responses to measles revaccination. We utilized a flow cytometry-based approach to examine whether T cell anergy and activation were associated with the maintenance of measles-specific immunoglobulin (Ig)G antibodies generated in response to measles revaccination in a cohort of HIV-infected children on ART in Nairobi, Kenya. Children who sustained measles-specific IgG for at least 1 year after revaccination displayed significantly lower programmed cell death 1 (PD-1) surface expression on CD8(+) T cells on a per-cell basis and exhibited less activated CD4(+) T cells compared to those unable to maintain detectable measles-specific antibodies. Children in both groups were similar in age and sex, CD4(+) T cell frequency, duration of ART treatment and HIV viral load at enrolment. These data suggest that aberrant T cell anergy and activation are associated with the impaired ability to sustain an antibody response to measles revaccination in HIV-infected children on ART.

Making wider use of the world's most widely used vaccine: Bacille Calmette-Guerin revaccination reconsidered

Approximately 100 million newborn children receive Bacille Calmette–Guérin (BCG) annually, because vaccination is consistently protective against childhood tuberculous meningitis and miliary TB. By contrast, BCG efficacy against pulmonary TB in children and adults is highly variable, ranging from 0% to 80%, though it tends to be higher in individuals who have no detectable prior exposure to mycobacterial infections, as judged by the absence of delayed-type hypersensitivity response (a negative tuberculin skin test, TST). The duration of protection against pulmonary TB is also variable, but lasts about 10 years on average. These observations raise the possibility that BCG revaccination, following primary vaccination in infancy, could be efficacious among TST-negative adolescents as they move into adulthood, the period of highest risk for pulmonary disease. To inform continuing debate about revaccination, this paper assesses the effectiveness and cost-effectiveness of revaccinating adolescents in a setting with intense transmission—Cape Town, South Africa. For a cost of revaccination in the range US$1–10 per person, and vaccine efficacy between 10% and 80% with protection for 10 years, the incremental cost per year of healthy life recovered (disability-adjusted life years, DALY) in the vaccinated population lies between US$116 and US$9237. The intervention is about twice as cost-effective when allowing for the extra benefits of preventing transmission, with costs per DALY recovered in the range US$52–$4540. At 80% efficacy, revaccination averted 17% of cases. Under the scenarios investigated, BCG revaccination is cost-effective against international benchmarks, though not highly effective. Cost-effectiveness ratios would be more favourable if we also allow for TB cases averted by preventing transmission to HIV-positive people, for the protection of HIV-negative people who later acquire HIV infection, for the possible non-specific benefits of BCG, for the fact that some adolescents would receive BCG for the first time, and for cost sharing when BCG is integrated into an adolescent immunization programme. These findings suggest, subject to further evaluation, that BCG revaccination could be cost-effective in some settings.

Revaccination of non- and low- responders after a standard three dose hepatitis B vaccine schedule

BACKGROUND

Guangdong province of China is HBV high endemicity and 1.6 million neonates are administrated 5 μg yeast recombinant anti-HBV vaccine each year. But few studies are performed to evaluate the immunogenicity and revaccination effect on non- and low- responders.

METHODS

2,199 children were administered intramuscularly with 5 μg vaccine at 0, 1 and 6 mo after birth. A 3 ml blood sample was drawn from each infant 1 mo after the third dose for determination of anti-HBs level. Three additional doses (10 μg each) were given to non- and low- responders.

RESULTS

Of 1,814 subjects, 3.1% were non-responders (anti-HBs titer < 10 mIUml (-1) ) and 28.9% were low-responders (anti-HBs ≥ 10 mIUml (-1) and < 100 mIUml (-1) ). Low birth weight (LBW) was a risk factor for non- and low- responders (RR = 1.6, 95%CI = 1.2-2.0). After revaccination, of the 34 non-responders, 14.7% became low-responders and 85.3% became responders. Of the 74 low-responders, 21.6% remained at the same level and 78.4% shifted into responder category.

CONCLUSIONS

Based on the lower responding rate after the primary immunization cycle and the higher responding rate after the additional cycle, measurement of anti-HBs level should be considered for people who had been immunized with three-dose 5 μg HB vaccine in Guangdong, especially for specific populations including LBW infants, healthcare workers, and patients with immunodeficiency disorders. An amount of 10 μg vaccine should be revaccinated to any non- and low- responders to provide adequate seroprotection.