Universal Mass Vaccination Against Rotavirus: Indirect Effects on Rotavirus Infections in Neonates and Unvaccinated Young Infants Not Eligible for Vaccination.

BACKGROUND: Rotavirus (RV)-associated infections account for high numbers of hospitalizations in neonates and young infants. Universal mass vaccination (UMV) has been shown to prevent the burden of disease in vaccinated children. METHODS: The present study investigated the long-term effects of UMV on RV-associated hospitalizations in children with particular focus on neonates and young infants (≤42 days old) not eligible for vaccination. Ten years of Austrian surveillance data were compared, including 10 960 laboratory-confirmed RV cases before (prevaccination period [PreVP]) and after (postvaccination period [PostVP]) introduction of UMV. RESULTS: A postvaccination decrease in hospitalized community-acquired RV infections by 89.3% was seen in all age groups, including unvaccinated neonates and young infants. Of the latter, 27.6% had a nosocomial RV infection in PreVP, and 19.3% in PostVP. Overall, the proportion of nosocomial RV infections increased from 5.5% in PreVP to 13.0% in PostVP. Breakthrough infections, usually after incomplete RV vaccination, could be identified in 6.2% of patients. CONCLUSIONS: Unvaccinated neonates and infants ≤42 days old may indirectly benefit from UMV by reduction of RV infections. Breakthrough infections underline the importance of early and complete protection by the vaccine. In older patients, heightened awareness of nosocomial RV infections is warranted. Identification of RV reservoirs is also needed.

Characteristics of invasive pneumococcal disease in hospitalized children in Austria.

UNLABELLED: In a prospective surveillance study covering all pediatric wards in Austria, 308 cases of invasive pneumococcal disease (IPD) were reported in hospitalized children <5 years of age between 2002 and 2012. Incidence was 7.1 per 100,000 per year for IPD with a case fatality rate of 3 %, and 1.9 per 100,000 per year for pneumococcal meningitis with a case fatality rate of 9 %. At hospital discharge, 17 % of the children were not fully recovered and suffered from problems such as hearing or motor deficits. Persistent sequelae 6 months after hospital discharge were present in 13 % of the children, a finding that emphasizes the seriousness of IPD. From 2007 onwards, we observed a shift of pneumococcal serotypes from those covered by the heptavalent vaccine to serotypes consequently added to 10- and 13-valent vaccines, particularly regarding serotype 19A. Among antimicrobial resistances detected, macrolide resistance was predominant; however, between 2002 and 2012, we saw an overall decrease of resistance rates. CONCLUSION: Considering this change of serotypes and the high rate of permanent sequelae after IPD, our data show the importance of pediatric pneumococcal vaccination and the relevance of continuous monitoring of circulating serotypes. By the end of 2012, which was the first year of universal mass vaccination against pneumococcal disease in Austria, no change in the incidence of invasive pneumococcal disease was observed yet.

Breakthrough Infections in SARS-CoV-2-Vaccinated Multiple Myeloma Patients Improve Cross-Protection against Omicron Variants.

Patients with multiple myeloma (MM) are a heterogenous, immunocompromised group with increased risk for COVID-19 morbidity and mortality but impaired responses to primary mRNA SARS-CoV-2 vaccination. The effects of booster vaccinations and breakthrough infections (BTIs) on antibody (Ab) levels and cross-protection to variants of concern (VOCs) are, however, not sufficiently evaluated. Therefore, we analysed humoral and cellular vaccine responses in MM patients stratified according to disease stage/treatment into group (1) monoclonal gammopathy of undetermined significance, (2) after stem cell transplant (SCT) without immunotherapy (IT), (3) after SCT with IT, and (4) progressed MM, and in healthy subjects (prospective cohort study). In contrast to SARS-CoV-2 hu-1-specific Ab levels, Omicron-specific Abs and their cross-neutralisation capacity remained low even after three booster doses in a majority of MM patients. In particular, progressed MM patients receiving anti-CD38 mAb and those after SCT with IT were Ab low responders and showed delayed formation of spike-specific B memory cells. However, MM patients with hybrid immunity (i.e., vaccination and breakthrough infection) had improved cross-neutralisation capacity against VOCs, yet in the absence of severe COVID-19 disease. Our results indicate that MM patients require frequent variant-adapted booster vaccinations and/or changes to other vaccine formulations/platforms, which might have similar immunological effects as BTIs.

SARS-CoV-2-mRNA Booster Vaccination Reverses Non-Responsiveness and Early Antibody Waning in Immunocompromised Patients - A Phase Four Study Comparing Immune Responses in Patients With Solid Cancers, Multiple Myeloma and Inflammatory Bowel Disease.

Background: Individuals with secondary immunodeficiencies belong to the most vulnerable groups to succumb to COVID-19 and thus are prioritized for SARS-CoV-2 vaccination. However, knowledge about the persistence and anamnestic responses following SARS-CoV-2-mRNA vaccinations is limited in these patients. Methods: In a prospective, open-label, phase four trial we analyzed S1-specific IgG, neutralizing antibodies and cytokine responses in previously non-infected patients with cancer or autoimmune disease during primary mRNA vaccination and up to one month after booster. Results: 263 patients with solid tumors (SOT, n=63), multiple myeloma (MM, n=70), inflammatory bowel diseases (IBD, n=130) and 66 controls were analyzed. One month after the two-dose primary vaccination the highest non-responder rate was associated with lower CD19+ B-cell counts and was found in MM patients (17%). S1-specific IgG levels correlated with IL-2 and IFN-γ responses in controls and IBD patients, but not in cancer patients. Six months after the second dose, 18% of patients with MM, 10% with SOT and 4% with IBD became seronegative; no one from the control group became negative. However, in IBD patients treated with TNF-α inhibitors, antibody levels declined more rapidly than in controls. Overall, vaccination with mRNA-1273 led to higher antibody levels than with BNT162b2. Importantly, booster vaccination increased antibody levels >8-fold in seroresponders and induced anamnestic responses even in those with undetectable pre-booster antibody levels. Nevertheless, in IBD patients with TNF-α inhibitors even after booster vaccination, antibody levels were lower than in untreated IBD patients and controls. Conclusion: Immunomonitoring of vaccine-specific antibody and cellular responses seems advisable to identify vaccination failures and consequently establishing personalized vaccination schedules, including shorter booster intervals, and helps to improve vaccine effectiveness in all patients with secondary immunodeficiencies. Trial registration: EudraCT Number: 2021-000291-11.

Neutralising SARS-CoV-2 RBD-specific antibodies persist for at least six months independently of symptoms in adults.

Background: In spring 2020, at the beginning of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic in Europe, we set up an assay system for large-scale testing of virus-specific and neutralising antibodies including their longevity. Methods: We analysed the sera of 1655 adult employees for SARS-CoV-2-specific antibodies using the S1 subunit of the spike protein of SARS-CoV-2. Sera containing S1-reactive antibodies were further evaluated for receptor-binding domain (RBD)- and nucleocapsid protein (NCP)-specific antibodies in relation to the neutralisation test (NT) results at three time points over six months. Results: We detect immunoglobulin G (IgG) and/or IgA antibodies reactive to the S1 protein in 10.15% (n = 168) of the participants. In total, 0.97% (n = 16) are positive for S1-IgG, 0.91% (n = 15) were S1-IgG- borderline and 8.28% (n = 137) exhibit only S1-IgA antibodies. Of the 168 S1-reactive sera, 8.33% (n = 14) have detectable RBD-specific antibodies and 6.55% (n = 11) NCP-specific antibodies. The latter correlates with NTs (kappa coefficient = 0.8660) but start to decline after 3 months. RBD-specific antibodies correlate most closely with the NT (kappa = 0.9448) and only these antibodies are stable for up to six months. All participants with virus-neutralising antibodies report symptoms, of which anosmia and/or dysgeusia correlate most closely with the detection of virus-neutralising antibodies. Conclusions: RBD-specific antibodies are most reliably detected post-infection, independent of the number/severity of symptoms, and correlate with neutralising antibodies at least for six months. They thus qualify best for large-scale seroepidemiological evaluation of both antibody reactivity and virus neutralisation.

Obesity and Sex Affect the Immune Responses to Tick-Borne Encephalitis Booster Vaccination.

Obesity has dramatically increased over the last 30 years and reaches according to World Health Organization dimensions of a global epidemic. The obesity-associated chronic low-level inflammation contributes to severe comorbidities and directly affects many immune cells leading to immune dysfunction and increased susceptibility to infections. Thus, prophylaxis against vaccine-preventable diseases is crucial, yet the responsiveness to several vaccines is unclear under obesity. In order to assess the responsiveness to tick-borne encephalitis (TBE) vaccine, we revaccinated 37 obese individuals and 36 normal-weight controls with a licensed TBE vaccine. Metabolic, hormonal, and immunologic profiles along with vaccine-specific humoral and cellular immune responses were evaluated in sera and peripheral blood mononuclear cells (PBMCs) before, 1 week, 4 weeks, and 6 months after TBE booster. Obese adults had significantly increased metabolic (triglycerides, cholesterol ratios, leptin, insulin) and proinflammatory (C-reactive protein) parameters. They showed stronger initial increase of TBE-specific Ab titers (d7_d28) followed by a significantly faster decline after 6 months, which correlated with high body mass index and leptin and insulin levels. The fold increase of Ab-titer levels was significantly higher in obese compared to control males and linked to reduced testosterone levels. Obesity also affected cellular responses: PBMCs of the obese vaccinees had elevated interleukin 2 and interferon γ levels upon antigen stimulation, indicating a leptin-dependent proinflammatory TH1 polarization. The expansion of total and naive B cells in obese might explain the initial increase of Ab titers, whereas the reduced B-memory cell and plasma blast generation could be related to fast Ab decline with a limited maintenance of titers. Among T follicular helper cell (Tfh) cells, the Tfh17 subset was significantly expanded particularly in obese males, where we observed a strong initial Ab increase. Systemic but not local vaccine side effects were more frequent in obese subjects as a possible consequence of their low-grade proinflammatory state. In summary, TBE booster vaccination was effective in obese individuals, yet the faster Ab decline could result in a reduced long-term protection. The sex-based differences in vaccine responses indicate a complex interplay of the endocrine, metabolic, and immune system during obesity. Further studies on the long-term protection after vaccination are ongoing, and also evaluation of primary vaccination against TBE in obese individuals is planned. Clinical Trial Registration: NCT04017052; https://clinicaltrials.gov/ct2/show/NCT04017052.

Correction: Invasive pneumococcal diseases in children and adults before and after introduction of the 10-valent pneumococcal conjugate vaccine into the Austrian national immunization program.

[This corrects the article DOI: 10.1371/journal.pone.0210081.].

Invasive pneumococcal diseases in children and adults before and after introduction of the 10-valent pneumococcal conjugate vaccine into the Austrian national immunization program.

BACKGROUND: In February 2012 the ten-valent pneumococcal conjugate vaccine (PCV10) with a 2+1 doses schedule (3, 5, 12 or 14 months of age) without catch-up vaccination was introduced in Austria. We assessed direct and indirect vaccine effects on invasive pneumococcal disease (IPD) by a population-based intervention study. METHODS: The study period was divided into pre- (2009-2011) and post-period (2013-2017, February), regarding 2012 as transition year. Outcomes were defined as PCV10 ST-IPD, the PCV10-related ST 6A and 19A IPD and non-PCV10 excluding ST 6A-/19A-IPD (NVT-IPD). We used national surveillance data and compared average monthly incidence rate (IR) between pre- and post-period among <5, 5-49 and ≥50 years old. Additionally, for the 5-49 and ≥50 years old, and the 50-59 and ≥60 years old, we analyzed monthly incidence data of the pre-, post-period, and estimated trend and level changes by using a segmented time-series regression. RESULTS: The PCV-10 IPD was reduced by 58% (95% CI: 30%; 74%) and 67% (95% CI: 32%; 84%) among <5 and ≥50 years old; the reduction in ≥60 years was 71% (95% CI: 36%; 88%). There were no significant changes in the pre-post-rate or incidence trend of NVT-IPD in the <5 and ≥50 years old. ST-specific analyses revealed no ST 6A- and ST 19A IPD decline in any age-group, and a ST 8 IPD increase among ≥50 years old (IR ratio: 3.5; 95% CI: 1.7; 7.2). We found no vaccine effects among 5-49 years old. CONCLUSIONS: Our study adds to the evidence on direct and indirect protection of a childhood PCV10 vaccine program. Elderlies seem to benefit the most. Findings did not support PCV 10 cross-protection, but indicate replacement at least for ST 8 among the ≥50 years old. Follow-up analyses of IPD surveillance data are needed to fully characterize the magnitude of serotype replacement and further vaccine-attributable IPD reduction with time.

Allergic patients with and without allergen-specific immunotherapy mount protective immune responses to tick-borne encephalitis vaccination in absence of enhanced side effects or propagation of their Th2 bias.

BACKGROUND: Allergic diseases are caused by Th2-driven immune responses and their treatment with specific immunotherapy (SIT) leads to immunomodulation via IL10, TGF-ß and Th1/Tr1 shift. This phase IV, open-label clinical trial investigated whether allergies and SIT treatment influenced immune responses to routine vaccination. METHODS: We studied three groups: 49 allergic patients (allergic group), 21 allergic patients receiving maintenance doses of SIT (SIT group), and 49 non-allergic controls. All subjects received tick-borne encephalitis (TBE) booster vaccines and humoral and cellular immune responses were evaluated after one week, four weeks and six months. RESULTS: The levels and kinetics of neutralizing TBE-specific antibodies, reflecting protection against TBE, were not significantly different in the three groups. The allergic group showed Th2 polarization pre-booster as indicated by increased TBE-specific IgG1 and elevated mitogen-induced IL5 production. Alum-adjuvanted TBE vaccine led to Th2 biased immune responses in the controls, but to no further enhancement of Th2 polarization in the allergic and SIT group. Furthermore, in the SIT group cellular parameters reflected the induction of immunomodulation due to increased Tregs, elevated baseline IL10 and lack of TBE-specific IL5. Importantly, these cellular regulatory responses did not limit the ability to mount sufficient TBE-specific antibodies after the booster. All groups tolerated the vaccine well with no exacerbation of allergic symptoms. CONCLUSION: TBE booster vaccinations were immunogenic and safe in both the allergic and SIT group and contributed to balanced immune responses. Our data indicate that all allergic patients, even when undergoing SIT, should be vaccinated without hesitation and at regular intervals according to standard recommendations. ClinicalTrials.gov (NCT02511535).

Persistence of antibodies six years after booster vaccination with inactivated vaccine against Japanese encephalitis.

BACKGROUND: Japanese Encephalitis (JE) virus occurs in wide regions of Asia with over 3 billion people living in areas at risk for JE. An estimated 68,000 clinical cases of JE occur every year, and vaccination is the most effective prophylactic measure. One internationally licensed vaccine containing the inactivated JE virus strain SA14-14-2 is Ixiaro (Valneva, Austria). According to recommendations, basic immunization consists of vaccinations on day 0, day 28, and a booster dose 12-24 months later. Protection in terms of neutralizing antibody titers has been assessed up to 12 months after the third dose of the vaccine. The current investigation was designed to evaluate antibody decline over time and to predict long-term duration of seroprotection after a booster dose. METHOD: In a preceding trial, volunteers received basic immunization (day 0, day 28) and one booster dose against JE 15 months later. A follow up blood draw 6 years following their booster dose was carried out in 67 subjects. For antibody testing, a 50% plaque reduction neutralization test (PRNT50-test) was used. PRNT50 values of 10 and above are surrogate levels of protection according to WHO standards. RESULT: Seventy-six months following the booster dose, 96% of the tested subjects had PRNT50 titers of 10 or higher. Geometric mean titer (GMT) was 148 (95% CI confidence interval: 107-207). Antibody titers were lower in volunteers 50 years of age and older. Vaccination history against other flaviviruses (yellow fever or tick borne encephalitis) did not significantly influence PRNT50 titers. A two-step log-linear decline model predicted protection against JE of approximately 14 years after the booster dose. CONCLUSION: Six years after a booster dose against JE, long-term protection could be demonstrated. According to our results, further booster doses should be scheduled 10 years following the first booster dose.

Sustained low hospitalization rates after four years of rotavirus mass vaccination in Austria.

This hospital based surveillance study evaluates the effects of the rotavirus mass vaccination program, which was initiated in Austria in August 2007. Since then, incidence rates of rotavirus hospitalizations in children <15 years of age have decreased by 70% and 64% in 2010 and 2011 compared to the pre-vaccination era (2001-2005). Incidence rates were highest in children <90 days of age, highlighting the importance of the early start of active rotavirus immunization. In children between 2 and 3.5 years in 2011, who were in the second and third year after vaccination in the universal mass vaccination program, incidence rates remained low suggesting sustained protection after vaccination up to three years. In the years 2010 and 2011, field effectiveness of the vaccines was between 79% and 96%, depending on the assumptions made for children without information on vaccination history. From genotyping an increase of the prevalence of G2P[4] in children with breakthrough infection (disease despite vaccination) can be suspected. The rate of severe adverse events was 1.3-1.5 per 10(-5) administered doses of rotavirus vaccines and no death, intussusception or Kawasaki disease was reported in 2010 and 2011 following rotavirus vaccination.