Ten-year follow-up on efficacy,immunogenicity and safety of two doses of a combined measles-mumps-rubella-varicella vaccine or one dose of monovalent varicella vaccine: Results from five East European countries

BackgroundWe assessed the 10-year efficacy, immunogenicity and safety of two doses of a combined measles-mumps-rubella-varicella vaccine (MMRV) or one dose of a monovalent varicella vaccine (V) in children from Czech Republic, Lithuania, Poland, Romania and Slovakia.MethodsThis was a phase IIIB follow-up of an observer-blind, randomized, controlled trial (NCT00226499). In phase A, healthy children aged 12–22 months from 10 European countries were randomized in a 3:3:1 ratio to receive two doses of MMRV (MMRV group), one dose of MMR followed by one dose of V (MMR + V group), or two doses of MMR (MMR; control group), 42 days apart. Vaccine efficacy (VE) against varicella (confirmed by viral DNA detection or epidemiological link and clinical assessment) was calculated with 95% confidence intervals using Cox proportional hazards regression model. Immunogenicity was assessed as seropositivity rates and geometric mean concentrations (GMCs). Solicited and unsolicited adverse events (AEs) and serious AEs (SAEs) were recorded.ResultsA total of 3705 children were vaccinated (1590, MMRV group; 1586, MMR + V group; 529, MMR group). There were 663 confirmed varicella cases (47, MMRV group; 349, MMR + V group; 267, MMR group). VE ranged between 95.4% (Lithuania) and 97.4% (Slovakia) in the MMRV group and between 59.3% (Lithuania) and 74% (Slovakia) in the MMR + V group. At year 10, seropositivity rates were 99.5%–100% in the MMRV group, 98%–100% in the MMR + V group and 50%–100% in the MMR control group, and the anti-VZV antibody GMCs were comparable between MMRV and MMR + V groups. The occurrence of solicited and unsolicited AEs was similar across groups and no SAE was considered as vaccination-related. No new safety concerns were identified.ConclusionsOur results indicated that two doses of varicella zoster virus-containing vaccine provided better protection than one dose against varicella and induced antibody responses that persisted 10 years post-vaccination.     

Randomized trial to evaluate the safety,tolerability, and immunogenicity of a booster (third dose) of BNT162b2 COVID-19 vaccine coadministered with 20-valent pneumococcal conjugate vaccine in adults ≥65 years old

BackgroundOlder adults are at increased risk of adverse outcomes from pneumococcal disease and COVID-19. Vaccination is an established strategy for preventing both illnesses. This study evaluated the safety and immunogenicity of coadministration of the 20-valent pneumococcal conjugate vaccine (PCV20) and a booster (third dose) of BNT162b2 COVID-19 vaccine.MethodsThis phase 3, randomized, double-blind, multicentre study included 570 participants aged ≥65 years randomized 1:1:1 to PCV20 and BNT162b2 coadministered, or PCV20 or BNT162b2 only (administered with saline for blinding). Primary safety endpoints included local reactions, systemic events, adverse events (AEs) and serious AEs (SAEs). Secondary objectives were immunogenicity of PCV20 and BNT162b2 when administered together or separately.ResultsCoadministration of PCV20 and BNT162b2 was well tolerated. Local reactions and systemic events were generally mild-moderate; injection-site pain and fatigue were the most frequent local and systemic events, respectively. AE and SAE rates were low and similar across groups. No AEs led to discontinuation; no SAEs were considered vaccination-related. Robust immune responses were observed, with opsonophagocytic activity geometric mean fold rises (GMFRs; from baseline to 1 month) of 2.5–24.5 and 2.3–30.6 across PCV20 serotypes in Coadministration and PCV20-only groups, respectively. GMFRs for full-length S-binding IgG of 35.5 and 39.0, and for neutralizing titres against SARS-CoV-2-wild type virus of 58.8 and 65.4, were observed in the Coadministration and BNT162b2-only groups, respectively.ConclusionsSafety and immunogenicity of coadministered PCV20 and BNT162b2 were similar to those of PCV20 or BNT162b2 administered alone, suggesting that the 2 vaccines may be coadministered.Trial Registration: ClinicalTrials.gov, NCT04887948.     

Reduced risk of serious pneumococcal infections up to 10 years after a dose of pneumococcal conjugate vaccine in established arthritis

BackgroundTo examine rates of serious pneumococcal infections up to 10 years after vaccination with 7-valent conjugated pneumococcal vaccine (PCV7) in patients with arthritis compared to non-vaccinated arthritis patients.MethodsIn total, 595 adult arthritis patients (rheumatoid arthritis; RA = 342, 80 % women and spondylarthropathy; SpA = 253, 45 % women) received one dose of PCV7. Mean age/disease duration were 62/16 and 51/14 years, respectively. For each patient, 4 matched reference subjects were identified.At vaccination, 420 patients received bDMARDs (anti-TNF = 330, tocilizumab = 15, abatacept = 18, anakinra = 1, rituximab = 56). Methotrexate was given as monotherapy (n = 86) or in combination with bDMARD (n = 220). 89 SpA patients received NSAIDs without DMARD.The Skåne Healthcare Register was searched for ICD-10 diagnostic codes for pneumococcal infections (pneumonia, lower respiratory tract infection, septicemia, meningitis, septic arthritis) between January 2000 and December 2018. Frequency of infections after vs before vaccination were calculated (relative risks). Relative risk ratio (RRR) and relative risk reduction (1-RRR) were calculated comparing patients vs non-vaccinated references. Kaplan-Meier and Cox regression were used to investigate time to first event and predictors of infections.ResultsAmong vaccinated RA and SpA patients, there was a significant relative risk reduction of pneumonia and all serious infections; 53% and 46%, respectively. There was no significant difference in time to first pneumonia or all serious infections after vaccination between patients and references. Higher age, RA diagnosis and concomitant prednisolone were associated with infections.ConclusionOne dose of pneumococcal conjugate vaccine may decrease risk of serious pneumococcal infection up to 10 years in patients with arthritis receiving immunomodulating treatment.     

A randomized phase 3 trial of the immunogenicity and safety of coadministration of a live-attenuated tetravalent dengue vaccine (TAK-003) and an inactivated hepatitis a (HAV) virus vaccine in a dengue non-endemic country

BackgroundVaccination against hepatitis A virus (HAV) is largely recommended for travelers worldwide. Concurrent dengue and HAV vaccination may be desired in parallel for travelers to countries where both diseases are endemic. This randomized, observer-blind, phase 3 trial evaluated coadministration of HAV vaccine with tetravalent dengue vaccine (TAK-003) in healthy adults aged 18–60 years living in the UK.MethodsParticipants were randomized (1:1:1) to receive HAV vaccine and placebo on Day 1, and placebo on Day 90 (Group 1), TAK-003 and placebo on Day 1, and TAK-003 on Day 90 (Group 2), or TAK-003 and HAV vaccine on Day 1, and TAK-003 on Day 90 (Group 3). The primary objective was non-inferiority of HAV seroprotection rate (anti-HAV ≥ 12.5 mIU/mL) in Group 3 versus Group 1, one month post-first vaccination (Day 30) in HAV-naïve and dengue-naïve participants. Sensitivity analyses were performed on combinations of baseline HAV and dengue serostatus. Secondary objectives included dengue seropositivity one month post-second vaccination (Day 120), HAV geometric mean concentrations (GMCs), and safety.Results900 participants were randomized. On Day 30, HAV seroprotection rates were non-inferior following coadministration of HAV and TAK-003 (Group 3: 98.7 %) to HAV administration alone (Group 1: 97.1 %; difference: ?1.68, 95 % CI: ?8.91 to 4.28). Sensitivity analyses including participants who were neither HAV-naïve nor DENV-naïve at baseline supported this finding. Anti-HAV GMCs on Day 30 were 82.1 (95 % CI: 62.9–107.1) mIU/mL in Group 1 and 93.0 (76.1–113.6) mIU/mL in Group 3. By Day 120, 90.9–96.8 % of TAK-003 recipients were seropositive (neutralizing antibody titer > 10) to all four dengue serotypes. Coadministration of HAV vaccine and TAK-003 was well tolerated, with no important safety risks identified.ConclusionImmune responses following coadministration of HAV vaccine and TAK-003 were non-inferior to administration of HAV vaccine alone. The results support the coadministration of HAV vaccine and TAK-003 with no adverse impact on immunogenicity, safety, and reactogenicity of either vaccine.ClinicalTrials.gov registration: NCT03525119.     

Long-term immunogenicity and safety of the hepatitis B vaccine HepB-CpG (HEPLISAV-B) compared with HepB-Eng (Engerix-B) in adults with chronic kidney disease

BackgroundHepatitis B virus (HBV) infection remains a significant global burden, especially for patients with chronic kidney disease (CKD) receiving hemodialysis. Three doses of HepB–CpG (HEPLISAV-B® vaccine) induced a superior immune response compared with 4 double doses of HepB–Eng (Engerix-B®) in a phase 3 trial (HBV-17) in adults with CKD. Here we report the long-term immunogenicity and safety of HepB-CpG and HepB–Eng in eligible participants of HBV-17 who enrolled in this optional 34-month follow-up trial (HBV-19).MethodsHBV-19 is a multicenter, open-label, phase 3b trial of adults with CKD who previously received a complete series of HepB-CpG or HepB-Eng in the HBV-17 trial. Participants were assigned to seroprotection categories at enrollment on the basis of their antibody response to hepatitis B surface antigen (anti-HBs) in HBV-17. The objective was to evaluate the durability of seroprotection (defined as an anti-HBs concentration ≥ 10 mIU/mL) induced by HepB-CpG and HepB-Eng. Participants whose anti-HBs concentration was below 10 mIU/mL received additional HepB-CpG or HepB-Eng doses.Results147 participants were enrolled; 66.7 % were men, median age was 65.0 years, and 83.7 % were white. The durability of seroprotection in participants with CKD was similar in those who received HepB-CpG and those who received HepB-Eng. Antibody concentrations ≥ 100 mIU/mL persisted for longer in HepB-CpG than HepB-Eng recipients, among those with anti-HBs ≥ 100 mIU/mL post vaccination. The geometric mean anti-HBs concentration in the HepB-CpG group was significantly higher than in the HepB-Eng group over time (P ≤ 0.0001). The safety profiles were similar between the vaccine groups.ConclusionsDue to the higher antibody levels induced by HepB-CpG in participants with CKD, seroprotection against HBV may be expected to persist longer than that induced by HepB-Eng. ClinicalTrials.gov: NCT01282762.     

Immunogenicity of the pneumococcal non-typeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV) administered concomitantly with the meningococcal serogroup B (4CMenB) vaccine in infants: A post-hoc analysis in a phase 3b,randomised, controlled trial

BackgroundNo data are currently available on immunogenicity of higher-valent pneumococcal conjugate vaccines when co-administered with a 4-component meningococcal serogroup B vaccine (4CMenB).MethodsPost-hoc analysis of pneumococcal non-typeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV) immunogenicity when co-administered with 4CMenB (2 + 1 schedule) and/or a CRM-conjugated meningococcal serogroup C vaccine (MenC-CRM) in a trial assessing 4CMenB reduced schedules and co-administration with MenC-CRM (NCT01339923). Infants were randomized to receive 4CMenB and MenC-CRM (Group 1) or MenC-CRM (Group 2) at 3, 5, and 12 months (M) of age. Both groups received PHiD-CV (3 + 1 schedule) as part of the Brazilian national immunisation programme at 3 M, 5 M, 7 M, and 12 M of age. Antibody responses were assessed pre-vaccination, 1 M post-dose 2, pre-booster, and 1 M post-booster.ResultsAnti-pneumococcal antibody responses were in similar ranges in the two study groups.Conclusions4CMenB co-administration did not seem to impact antibody responses to PHiD-CV in infants.     

Safety of meningococcal B vaccine (4CMenB) in adolescents in Australia

BackgroundFour-component meningococcal B (4CMenB) vaccine is licensed in many countries but has had limited use in adolescents despite this age group being at increased risk of meningococcal disease.ObjectivesTo assess the safety profile of two doses of 4CMenB in adolescents.MethodsCluster randomised controlled trial of senior school students in South Australia (SA) with participating schools randomised to intervention (4CMenB) or control. Vaccine safety was monitored using the South Australian Vaccine Safety Surveillance System (SAVSS), a spontaneous reporting system for adverse events following immunisation (AEFI) with enhanced follow-up of AEFI.Results58,637 doses of 4CMenB vaccine were administered to 30,522 students (median age 16 years) during 2017–2018. Of 18,348 and 12,174 students vaccinated in 2017 and 2018, 97.3% and 84.3%, respectively, received both scheduled doses (N = 28,115). 193 AEFI in 187 students were reported with a reporting rate of 0.32% (95%CI: 0.28–0.39%). Seventy individuals sought medical review, including nine serious adverse events. 98% (166/169) of those who were contactable for AEFI follow-up (87.6% 169/193) reported resolution of the event. Most common AEFI were injection site reaction (126/193), headache (99/193) and nausea (61/193). AEFI were more frequently reported in females (aOR = 1.409 (95%CI: 1.002, 1.980)), schools with high level of educational advantage (adjusted Odds Ratio (aOR) = 1.515 (95%CI: 1.005, 2.284)), following first dose (aOR = 1.619 (95%CI: 1.168, 2.244)), and in 2017 (aOR = 1.437 (95%CI: 1.001, 2.064)). Reported AEFI declined with increasing age (aOR = 0.771 (95%CI: 0.673, 0.883)).ConclusionIn this largest post-licensure use of 4CMenB in adolescents, the low AEFI reporting rate provides real-world evidence of 4CMenB safety in this age group.(ClinicalTrials.gov number: NCT03089086).     

Immune response at 12–23 months following a single dose of Vero cell culture-derived Japanese encephalitis (JE) vaccine in adults previously vaccinated with mouse brain-derived JE vaccine

BackgroundJapanese encephalitis (JE) virus is an important cause of neurological disease in Asia. JE vaccine is recommended for travelers with higher JE risk itineraries. Inactivated Vero cell culture-derived JE vaccine (JE-VC) is the only JE vaccine currently available in the United States. An inactivated mouse brain-derived JE vaccine (JE-MB) previously was available but production was discontinued. One JE-VC dose administered to adults previously vaccinated with ≥3 doses of JE-MB provides good short-term protection for at least one month, but data on longer-term protection are limited. We evaluated non-inferiority of the JE virus neutralizing antibody response at 12–23 months in JE-MB-vaccinated adults administered one JE-VC dose compared with JE vaccine-naïve adults administered a JE-VC two-dose primary series.MethodsWe obtained archived sera from U.S. military personnel and performed a 50% plaque reduction neutralization test for anti-JE virus neutralizing antibodies. We compared the geometric mean titer (GMT) and seroprotection rate at 12–23 months after one JE-VC dose in previously JE-MB-vaccinated personnel and after the second JE-VC dose in previously JE vaccine-naïve personnel. Non-inferiority was concluded if the lower bound of the two-sided 95% confidence interval (CI) of the GMT ratio in previously vaccinated to vaccine-naïve personnel was >1/1.5.ResultsThe GMT in previously JE-MB-vaccinated persons was 75 (95% CI 63–90) and in previously JE vaccine-naïve persons was 12 (95% CI 11–14), and seroprotection rates were 94% (235/250) and 54% (135/250), respectively. The ratio of GMTs was 6.3 (95% CI: 5.0–7.7), satisfying the criterion for non-inferiority.ConclusionsOne JE-VC dose in previously JE-MB-vaccinated military personnel provides good protection for at least 1–2 years. The benefits of administration of a single JE-VC dose in previously JE-MB-vaccinated adults include a shorter time to completion of re-vaccination before travel, a decrease in the risk of adverse events, and reduced costs.     

Booster vaccination with a fractional dose of an oral cholera vaccine induces comparable vaccine-specific antibody avidity as a full dose: A randomised clinical trial

Antibody avidity is an important measure of the quality of vaccine-induced immune responses. Murine and human studies suggest that antibody avidity may be augmented by limiting access to antigen. The primary objective of this study was to evaluate in primed Swedish adults if booster vaccination with fractional doses (1/5th and 1/25th) of a model oral vaccine, the cholera vaccine Dukoral®, results in higher avidity antibody responses compared to boosting with a full vaccine dose. We also evaluated if fractional booster vaccination elicited similar magnitudes of antibody response compared to a full dose, and if the previously observed increase in antibody avidity after booster vaccination 1–2 years later occurred when boosting after a shorter interval.To this end, a randomised, open-label, exploratory Phase-II trial was performed. Swedish adults (n = 44), primed with two full doses of Dukoral®, were randomised into three groups and given a booster dose at either full (n = 14), 1/5th (n = 17) or 1/25th (n = 13) dose four months later. Antibody responses to cholera toxin B-subunit (CTB) were measured in serum and mucosal antibody in lymphocyte secretions (ALS).We found that the 1/5th and 1/25th booster doses had similar abilities as the full dose to induce significantly higher avidity anti-CTB antibody responses in both ALS and serum samples, as compared to after priming vaccination. There was a non-significant trend to lower magnitudes of ALS and serum IgA responses after the 1/5th compared to the full booster dose, and responses after the 1/25th dose were significantly lower.Our findings suggest fractional booster doses of Dukoral® four months after priming result in anti-toxoid mucosal antibody responses with increased antibody avidity compared to after priming vaccinations.ISRCTN registry identifier 11806026.     

Pertussis burden and acellular pertussis vaccine effectiveness in high risk children

BackgroundPertussis hospitalisation is more common among infants born prematurely, who have significant comorbidities, or are Indigenous, but acellular pertussis (aP) vaccine effectiveness (VE) estimates in these sub-groups are lacking. We measured aP VE by Indigenous status, and policy-relevant categories of prematurity and comorbidity, in a population-based Australian cohort.MethodsPerinatal, disease notification, hospitalisation, mortality, and vaccination data were linked to birth records in two Australian states (Western Australia and New South Wales) 2001–2012, with follow-up to the end of 2013. Children followed to 18 months of age were stratified by Aboriginality, prematurity (<32 vs 32–<37 weeks gestation) and comorbidities identified from hospital discharge coding. Rates, rate ratios and VE were calculated for first episode of hospitalised and non-hospitalised pertussis notifications using adjusted Cox proportional hazards models.ResultsAmong >1,300,000 children, 63,867 (4·9%) were Aboriginal, 47,721 (3·6%) had at least one comorbidity and 3,771 first episodes of notified pertussis occurred <18 months of age; of these, 1,207 (32.0%) had an associated pertussis-coded hospitalisation. For hospitalised pertussis in Aboriginal and non-Aboriginal children, there was significant protection post dose 1 (VE 51% v 25%), 2 (VE 69% v 74%) and 3 (VE 76% v 80%). For children with co-morbidities, VE for hospitalised pertussis was low and non-significant post dose 1 (0%) and 2 (30%). Post dose 3, VE was significant for hospitalised pertussis (70%; 95% CI 29–87) but not for non-hospitalised pertussis (24%; 95% CI ?49 to 61).ConclusionsFor most Aboriginal and non-Aboriginal children, improved timeliness of current infant doses and higher antenatal coverage should further improve protection against pertussis of any severity. For children at highest risk of severe pertussis (born <32 weeks gestation or with significant medical comorbidities), our data suggest that additional measures-such as extra doses of pertussis-containing vaccines and/or vaccines with improved immunogenicity–are needed for protection.     

A phase 1 antigen dose escalation trial to evaluate safety,tolerability and immunogenicity of the leprosy vaccine candidate LepVax (LEP-F1 + GLA–SE) in healthy adults

Healthy United States-based adult volunteers with no history of travel to leprosy-endemic countries were enrolled for the first-in-human evaluation of LepVax (LEP-F1 + GLA-SE). In total 24 volunteers participated in an open-label clinical trial, with 21 receiving three injections of LepVax consisting of either 2 µg or 10 µg recombinant polyprotein LEP-F1 mixed with 5 µg of the GLA-SE adjuvant formulation. LepVax doses were provided by intramuscular injection on Days 0, 28, and 56, and safety was evaluated for one year following the final injection. LepVax was safe and well tolerated at both antigen doses. Immunological analyses indicated that similar LEP-F1-specific antibody and Th1 cytokine secretion (IFN-γ, IL-2, TNF) were induced by each of the antigen doses evaluated within LepVax. This clinical trial of the first defined vaccine candidate for leprosy demonstrates that LepVax is safe and immunogenic in healthy subjects and supports its advancement to testing in leprosy-endemic regions.     

Effectiveness of recombinant zoster vaccine (RZV) in patients with inflammatory bowel disease

Background and AimsPatients with Inflammatory bowel disease (IBD) are at an increased risk of developing herpes zoster (HZ). The effectiveness of the recombinant zoster vaccine (RZV) in patients with IBD is unknown.MethodsIn this retrospective cohort study using Explorys (October 2017–April 2020; IBM Corporation, Somers, NY, USA), the effectiveness of RZV for the prevention of HZ in patients with IBD ≥ 50 years was compared to general population aged ≥ 50 years. Rates of de-novo HZ were compared between patients with IBD and the general population and stratified by number of RZV doses received. Results are presented as odds ratios (OR) with 95% confidence intervals (CI).ResultsThe overall proportion of IBD patients ≥ 50 years who received HZ vaccination with the live zoster vaccine (ZVL) or RZV was low (n = 11320, out of 112,200 IBD patients in the cohort). A total of 1670 patients received RZV. Receipt of the RZV resulted in a significantly lower rate of HZ in IBD patients (OR 0.36, 95% CI 0.23–0.56) compared to the general population (OR 0.74, 95% CI 0.59–0.92). However, despite vaccination, patients with IBD who received the RZV were still 3-times more likely to develop HZ during the study follow up period compared to the general population receiving the RZV (OR 3.06, 95% CI 1.87–5.02) and unvaccinated IBD patients were 6-times more likely to develop HZ compared to general population (OR 6.21, 95% CI 6.02–6.41).ConclusionThe recombinant zoster vaccine is effective in reducing the risk of HZ in patients with IBD compared to the general population. During our follow up period, patients with IBD, however, still remain at an increased risk for HZ despite vaccination.     

Individual factors influencing COVID-19 vaccine acceptance in between and during pandemic waves (July–December 2020)

BackgroundA year after the start of the COVID-19 outbreak, the global rollout of vaccines gives us hope of ending the pandemic. Lack of vaccine confidence, however, poses a threat to vaccination campaigns. This study aims at identifying individuals’ characteristics that explain vaccine willingness in Flanders (Belgium), while also describing trends over time (July–December 2020).MethodsThe analysis included data of 10 survey waves of the Great Corona Survey, a large-scale online survey that was open to the general public and had 17,722–32,219 respondents per wave. Uni- and multivariable general additive models were fitted to associate vaccine willingness with socio-demographic and behavioral variables, while correcting for temporal and geographical variability.ResultsWe found 84.2% of the respondents willing to be vaccinated, i.e., respondents answering that they were definitely (61.2%) or probably (23.0%) willing to get a COVID-19 vaccine, while 9.8% indicated maybe, 3.9% probably not and 2.2% definitely not. In Flanders, vaccine willingness was highest in July 2020 (90.0%), decreased over the summer period to 80.2% and started to increase again from late September, reaching 85.9% at the end of December 2020. Vaccine willingness was significantly associated with respondents’ characteristics: previous survey participation, age, gender, province, educational attainment, household size, financial situation, employment sector, underlying medical conditions, mental well-being, government trust, knowing someone with severe COVID-19 symptoms and compliance with restrictive measures. These variables could explain much, but not all, variation in vaccine willingness.ConclusionsBoth the timing and location of data collection influence vaccine willingness results, emphasizing that comparing data from different regions, countries and/or timepoints should be done with caution. To maximize COVID-19 vaccination coverage, vaccination campaigns should focus on (a combination of) subpopulations: aged 31–50, females, low educational attainment, large households, difficult financial situation, low mental well-being and labourers, unemployed and self-employed citizens.     

Immunogenicity and safety of a single booster dose of NVX-CoV2373 (TAK-019) in healthy Japanese adults who had previously received a primary series of COVID-19 mRNA vaccine: Primary analysis report of a phase 3 open-label trial

BackgroundWe evaluated the immunogenicity and safety of a booster dose of NVX-CoV2373 in Japanese adults who had completed a primary series of COVID-19 mRNA vaccine 6–12 months previously.MethodsThis single-arm, open-label, phase 3 study, conducted at two Japanese centres, enrolled healthy adults ≥ 20 years old. Participants received a booster dose of NVX-CoV2373. The primary immunogenicity endpoint was non-inferiority (lower limit of the 95 % confidence interval [CI] ≥ 0.67) of the geometric mean titre (GMT) ratio of titres of serum neutralizing antibodies (nAbs) against the SARS-CoV-2 ancestral strain 14 days after booster vaccination (day 15) in this study, compared with those 14 days after the second primary NVX-CoV2373 vaccination (day 36) in the TAK-019-1501 study (NCT04712110). Primary safety endpoints included local and systemic solicited adverse events (AEs) up to day 7 and unsolicited AEs up to day 28.ResultsBetween 15 April 2022 and 10 May 2022, 155 participants were screened and 150, stratified by age (20–64 years old [n = 135] or ≥ 65 years old [n = 15]), received an NVX-CoV2373 booster dose. The GMT ratio between titres of serum nAbs against the SARS-CoV-2 ancestral strain on day 15 in this study and those on day 36 in the TAK-019-1501 study was 1.18 (95 % CI, 0.95–1.47), meeting the non-inferiority criterion. Following vaccination, the proportion of participants who reported local and systemic solicited AEs up to day 7 was 74.0 % and 48.0 %, respectively. The most common local and systemic solicited AEs were tenderness (102 participants [68.0 %]) and malaise (39 participants [26.0 %]), respectively. Seven participants (4.7 %) reported unsolicited AEs between vaccination and day 28; all were severity grade ≤ 2.DiscussionA single heterologous NVX-CoV2373 booster induced rapid and robust anti-SARS-CoV-2 immune responses, addressing waning immunity in healthy Japanese adults, and had an acceptable safety profile.ClinicalTrials.gov identifier: NCT05299359.     

Changes in hepatitis B vaccine perception in response to the COVID-19 pandemic: Development of the Shift in vaccine confidence (SVC) survey tool

The COVID-19 pandemic has disrupted access to, adherence to, and perceptions of routine vaccinations. We developed the Shift in Vaccine Confidence (SVC) survey tool to assess the impact of the pandemic on routine vaccinations, with a focus on the HBV vaccine, in Kinshasa, Democratic Republic of Congo (DRC). This study describes the content validation steps we conducted to ensure the survey tool is meaningful to measure changes in vaccine confidence to regular immunization (HBV vaccine) due to the pandemic. Three rounds of stakeholder feedback from a DRC-based study team, content and measurement experts, and study participants allowed us to produce a measure with improved readability and clarity.     

Assessing the impact of the routine childhood hepatitis B immunization program and the need for hepatitis B vaccine birth dose in Sierra Leone, 2018

Sierra Leone is highly endemic for hepatitis B virus (HBV) infection and thus recommends three doses of hepatitis B vaccine (HepB3) from 6 weeks of age but does not recommend a birth dose (HepB-BD) to prevent mother-to-child transmission (MTCT). We evaluated impact of the existing HepB3 schedule and risk for MTCT of HBV. We conducted a community-based serosurvey among 4–30-month-olds, their mothers, and 5–9-year-olds in three districts in Sierra Leone. Participants had an HBV surface antigen (HBsAg) rapid test; all HBsAg-positive and one HBsAg-negative mother per cluster were tested for HBV markers. We collected children’s HepB3 vaccination history. Among 1889 children aged 4–30 months, HepB3 coverage was 85% and 20 (1·3% [95% CI 0·8–2·0]) were HBsAg-positive, of whom 70% had received HepB3. Among 2025 children aged 5–9 years, HepB3 coverage was 77% and 32 (1·6% [1·1–2·3]) were HBsAg-positive, of whom 56% had received HepB3. Of 1776 mothers, 169 (9·8% [8·1–11·7]) were HBsAg-positive. HBsAg prevalence was 5·9% among children of HBsAg-positive mothers compared to 0·7% among children of HBsAg-negative mothers (adjusted OR = 10·6 [2·8–40·8]). HBsAg positivity in children was associated with maternal HBsAg (p = 0·026), HBV e antigen (p < 0·001), and HBV DNA levels ≥ 200 000 IU/mL (p < 0·001). HBsAg prevalence was lower among children than mothers, for whom HepB was not available, suggesting routine infant HepB vaccination has lowered HBV burden. Since HBsAg positivity in children was strongly associated with maternal HBV infection and most of the HBsAg-positive children in the survey received HepB3, HepB-BD may prevent MTCT and chronic HBV infection.     

Incidence of herpes zoster among varicella-vaccinated children,by number of vaccine doses and simultaneous administration of measles,mumps, and rubella vaccine

IntroductionChildren may receive measles-mumps-rubella (MMR) and varicella (VAR) vaccines separately or as measles-mumps-rubella-varicella (MMRV). We examined whether pediatric herpes zoster (HZ) incidence varied by pattern of varicella vaccine administration.MethodsIn six integrated health systems, we examined HZ incidence among children turning 12 months old during 2003–2008. All received varicella and MMR vaccines on recommended schedules. Cases were identified through 2014 using ICD-9 codes. Incidence was examined by number of varicella vaccine doses and same-day MMR.ResultsAmong 199,797 children, overall HZ incidence was 18.6/100,000 person-years in the first-dose MMR + VAR group, 17.9/100,000 person-years in the MMRV group, and 7.5/100,000 person-years in the VAR-alone group. HZ incidence was lower following the second dose than before the second dose in all first-dose groups.ConclusionsHZ incidence was not meaningfully different between the MMRV and MMR + VAR first-dose groups. Overall and within first-dose groups, HZ incidence was lower among children receiving two varicella vaccine doses.     

Assessment of the efficacy of an attenuated live marker classical swine fever vaccine (Flc-LOM-BErns) in pregnant sows

Here, we constructed an attenuated live marker classical swine fever (CSF) vaccine (Flc-LOM-BE^rns) to eradicate CSF. This was done by taking infectious clone Flc-LOM, which is based on an attenuated live CSF vaccine virus (LOM strain), and removing the full-length classical swine fever virus (CSFV) E^rns sequences and the 3′ end (52 base pairs) of the CSFV capsid. These regions were substituted with the full-length bovine viral diarrhoea virus (BVDV) E^rns gene sequence and the 3′ end (52 base pairs) of the BVDV capsid gene. Sows were vaccinated with the Flc-LOM-BE^rns vaccine 3 weeks before insemination and then challenged with virulent CSFV at the early, mid- or late stages of pregnancy. We then examined transplacental transmission to the foetuses. Piglets born to sows vaccinated with Flc-LOM-BE^rns did not show vertical infection, regardless of challenge time. In addition, CSFV challenge did not affect the delivery date, weight or length of the foetus. Pregnant sows inoculated with the Flc-LOM-BE^rns vaccine were anti-CSF E^rns antibody-negative and anti-BVDV E^rns antibody-positive. Challenge of pregnant sows with virulent CSFV resulted in anti-CSF E^rns antibody positivity. These results strongly indicate that differential diagnosis can be conducted between the Flc-LOM-BE^rns vaccinated animal and virulent CSFV affected animal by detecting antibody against BVDV E^rns or CSF E^rns gene. Therefore, the Flc-LOM-BE^rns vaccine may fulfil the function of differential diagnosis which required for DIVA vaccine.