The following products were used: Allergovit 006 (grasses, 100%; article no. immunogenicity studies, we have used a dose (ie, 20 g of each of the 4BM fusion proteins) that has Azithromycin (Zithromax) been safely administered to allergic patients (ClinicalTrials.gov identifiers “type”:”clinical-trial”,”attrs”:”text”:”NCT01445002″,”term_id”:”NCT01445002″NCT01445002, “type”:”clinical-trial”,”attrs”:”text”:”NCT01538979″,”term_id”:”NCT01538979″NCT01538979, and “type”:”clinical-trial”,”attrs”:”text”:”NCT02643641″,”term_id”:”NCT02643641″NCT02643641).4 The main finding of our current study was that 3 month to month subcutaneous injections of PTGER2 aluminium hydroxideCadsorbed BM32 induced IgG antibody levels to the major grass pollen allergens Phl p 1, Phl p 5, and Phl p 6 in rabbits, which were comparable with natural allergen extractCbased registered grass pollen allergy vaccines requiring more than 8 injections (Allergovit grass; Allergopharma, Reinbek, Germany; Alutard SQ grass mix; ALK-Abell, H?rsholm, Denmark; and Phostal grasses + rye; Stallergenes, Antony, France; see the Methods section in this articles Online Repository at www.jacionline.org; Azithromycin (Zithromax) Fig 1), whereas almost no response was observed with Pollinex (Pollinex Quattro Plus grasses + rye; Bencard Allergie GmbH, Munich, Germany), a vaccine based on 4 injections. Importantly, BM32 induced higher levels of Phl p 2Cspecific IgG antibodies than any of the registered allergen extractCbased vaccines Azithromycin (Zithromax) (Fig 1). We consider this an important obtaining because it has been shown that group 2 allergens are major grass pollen allergens recognized by more than 60% of patients with grass pollen allergy and, when compared with the other grass pollen allergens by using skin testing, were found to show high allergenic potency.5 Thus our results indicate that it should be possible to build up sufficient levels of grass pollen allergenCspecific IgG responses with only few injections (ie, 3-5) of BM32, whereas traditional allergy vaccines require more than double the number of updosing injections. Sublingual treatment even requires daily administration. Therefore we think that the treatment schedules based on BM32 will Azithromycin (Zithromax) be more convenient for patients and should increase their compliance. Open in a separate windows Fig 1 Induction of grass pollen allergenCspecific IgG responses in rabbits by means of immunization with BM32, recombinant grass pollen allergens, and natural grass pollen AIT extracts. Azithromycin (Zithromax) A, Plan of rabbit immunizations. Rabbits were immunized with 3 monthly injections of BM32 or a mix of recombinant grass pollen allergens. In parallel, rabbits were immunized with registered grass pollen extractCbased AIT vaccines (Allergovit, Alutard, Phostal, and Pollinex), as recommended by the manufacturer. Serum samples were collected from all rabbits shortly before the first immunization and in monthly intervals (at different time points = .0008, Fig 2). Anti-Pollinex antibodies produced less than 10% inhibition of IgE binding to the allergens and timothy grass pollen extract and thus inhibited IgE binding to timothy grass pollen extract and the individual grass pollen allergens significantly less (= .0008) than those induced by all the other vaccines. The induction of grass pollen allergenCspecific IgG by 4 injections of Pollinex was also modest in allergic patients and only significant after the second treatment 12 months.8,9 Open in a separate window Fig 2 Inhibition of IgE binding in allergic patients to grass pollen allergens with rabbit antibodies induced by vaccination. Shown are the percentages of inhibition of IgE binding to timothy grass pollen extract, Phl p 1, Phl p 2, Phl p 5, and Phl p 6 by anti-Allergovit, anti-Alutard, anti-Phostal, anti-Pollinex, or anti-BM32 rabbit antibodies .05, ** .01, and *** .001. = .0008, Fig 2). Therefore one might presume that BM32 could be superior to the extract-based vaccines regarding protection of group 2 allergenCinduced symptoms. Finally, we also could demonstrate that BM32-induced antibodies inhibited specifically grass pollen.