Pneumococcal immunity and PCV13 vaccine response in SOT-candidates and recipients.

BACKGROUND: Solid organ transplantation (SOT) candidates and recipients are highly vulnerable to invasive pneumococcal diseases (IPD). Data on which to base optimal immunization recommendations for this population is scant. The national distribution of IPD serotypes led the Swiss Health Authorities to recommend in 2014 one dose of pneumococcal-13-valent-conjugate-vaccine (PCV13), without any subsequent dose of the 23-valent-polysaccharide-pneumococcal-vaccine (PPV23). METHODS: This is a retrospective analysis of pneumococcal immunity using a multiplex binding assay, to assess seroprotection rates against a selection of seven PCV13- and seven PPV23-serotypes in SOT-candidates and recipients evaluated and/or transplanted in 2014/2015 in the University Hospitals of Geneva. Seroprotection was defined as serotype-specific antibody concentration greater than 0.5 mg/l and overall seroprotection when this was achieved for ≥ 6/7 serotypes. RESULTS: Pre-vaccination and at time of transplant sera were available for 35/43 (81%), and 43/43 (100%) SOT-candidates respectively. At listing, 17/35 (49%) SOT-candidates were seroprotected against PCV13 and 21/35 (60%) against PPV23 serotypes. Following one systematic dose of PCV13 at listing, 35/43 (81%) SOT-recipients were seroprotected at day of transplant against PCV13-serotypes and 34/43 (79%) against PPV23 serotypes, compared to 21/41 (51%) and 28/41 (68%) respectively in the controls transplanted in 2013, before the systematic PCV13-vaccination. CONCLUSIONS: The systematic vaccination with PCV13 of all SOT candidates without additional PPV23 is a good strategy as it confers seroprotection against a wide range of pneumococcal serotypes. Indeed, one of five PCV13-vaccinated SOT-candidates was nevertheless not seroprotected at time of transplant, reflecting their partial immune competence, and indicating the need for additional dose of pneumococcal vaccines before transplant.

Safety and immunogenicity of the epicutaneous reactivation of pertussis toxin immunity in healthy adults: a phase I, randomized, double-blind, placebo-controlled trial.

OBJECTIVES: Protection induced by acellular vaccines can be short, requiring novel immunization strategies. Objectives of this study were to evaluate safety and capacity of a recombinant pertussis toxin (PTgen) -coated Viaskin® epicutaneous patch to recall memory responses in healthy adults. METHODS: This double-blind, placebo-controlled randomized trial (Phase I) assessed the safety and immunogenicity of PTgen administered on days 0 and 14 to healthy adults using Viaskin® patches applied directly or after epidermal laser-based skin preparation. Patch administration was followed by Boostrix®dTpa on day 42. Antibodies were assessed at days 0, 14, 28, 42 and 70. RESULTS: Among 102 volunteers enrolled, 80 received Viaskin-PT (Viaskin-PT 25 µg (n = 25), Viaskin-PT 50 µg (n = 25), laser + Viaskin-PT 25 µg (n = 5), laser + Viaskin-PT 50 µg (n = 25)), Viaskin-placebo (n = 10) or laser + Viaskin-placebo (n = 2). Incidence of adverse events was similar across groups (any local event: 21/25 (84.0%), 24/25 (96.0%), 4/5 (80.0%), 24/25 (96.0%), 8/10 (80.0%), 10/12 (83.0%), respectively). Direct application induced no detectable response. On day 42, PT-IgG geometric mean concentrations were significantly higher following laser + Viaskin-PT 25 µg and 50 µg (139.87 (95% CI 87.30-224.10) and 121.76 (95% CI 95.04-156.00), respectively), than laser + Viaskin-placebo (59.49, 95% CI 39.37-89.90). Seroresponse rates were higher following laser + Viaskin-PT 25 µg (4/5 (80.0%), 95% CI 28.4-99.5) and 50 µg (22/25 (88.0%), 95% CI 68.8-97.5) than laser + Viaskin-placebo (0/12 (0.0%), 95% CI 0.0-26.5). CONCLUSIONS: Viaskin-PT applied after laser-based epidermal skin preparation showed encouraging safety and immunogenicity results: anti-PT booster responses were not inferior to those elicited by Boostrix®dTpa. This study is registered at ClinicalTrials.gov (NCT03035370) and was funded by DBV Technologies.

Vaccination against seasonal flu in Switzerland: The indecision of pregnant women encouraged by healthcare professionals.

BACKGROUND: The recommendation for seasonal flu immunization from the second trimester of pregnancy, adopted in summer 2010 in Switzerland, is situated within a social context characterized by reluctance toward some vaccinations, a relatively low vaccination coverage against flu in the general population, and still heated debates fuelled by vaccination campaigns organized around the A(H1N1)pdm09 flu pandemic in winter 2009 to 2010. This study examines Swiss pregnant women's representations of the risks associated with seasonal flu and its vaccination. METHODS: Semi-structured interviews were conducted with 29 women, while in the maternity unit in March 2011, 3 to 5 days after giving birth. The interviews addressed the risks associated with flu, modes of protection, motivations for, and obstacles to vaccination. RESULTS: The interviewees did not show major preoccupations regarding seasonal flu and they tended to distance themselves from the at-risk status. They did not directly challenge seasonal flu immunization; however, they were reluctant to do it. Their attitudes were supported by their personal experience and the experience of their social networks. Healthcare professionals, particularly medical doctors, gave very little direction, or even did not raise the issue with them. CONCLUSIONS: Between the rather moderate positions of those who are against vaccination and those who support it, an intermediate grey zone, characterized by hesitation, was observed. Furthermore, the indecision of pregnant women is reinforced by doubts among the persons they are close to and also among the professionals they met during their pregnancy.