Chadox1 ncov 19 vaccine

Ten- to twelve-week-old BALB/c mice (Charles River) were maintained in pathogen-free, individually ventilated cages, and fed with sterilized diet for laboratory rodents. All experiments were in accordance with policies and procedures of institutional guidelines and approved by the Animal Care Commission of the Government Baden-Württemberg. Animals were briefly anesthetized with sevoflurane and injected intramuscularly with phosphate-buffered saline (PBS) or 1 × 10⁹ vector particles of AstraZeneca ChAdOx1 nCoV-19 vaccine ABV9317 or UUlm ChAdOx1 dissolved in sterile PBS in final volumes of 100 µl (50 µl/M. gastrocnemii). To exclude effects induced by AstraZeneca ChAdOx1 nCoV-19 vaccine buffer components, UUlm ChAdOx1 samples were supplemented with equal amounts of the buffer. Fourteen days after injection, animals were sacrificed by overdosed sevoflurane anesthesia and subsequent mechanical rupture of the diaphragm, blood samples were collected and anticoagulated with 1 U/ml heparin. Plasma was prepared by centrifugation of blood samples for 45 min at 800 × g and stored at −20°C. Additionally, spleens were isolated and directly used for the determination of Spike-specific T-cell responses. n = 6/group (4× female, 2× male).

Vaccination status was divided into three categories: nonvaccinated, partially vaccinated, and fully vaccinated. Patients with a positive COVID-19 RT-PCR test result and onset of symptoms at least 14 days after receipt of the second vaccine dose (ChAdOx1 nCoV-19 vaccine-AstraZeneca, BNT162b2vaccine-Pfizer-BioNTech, mRNA-1273 vaccine–Moderna) were defined as fully vaccinated. Patients who had received Ad26.COV2.S vaccine-Johnson & Johnson-Janssen as the first vaccine required a second vaccine dose with a mRNA vaccine at least 14 days before a positive COVID-19 RT-PCR test result and onset of symptoms to be considered as fully vaccinated, as recommended in Germany by the Federal ministry of health [24 ]. The date of vaccination was not consistently recorded and could not be included.

Mice were monitored twice per day to evaluate early signs of pain and distress, such as respiration rate, posture, and loss of weight (more than 20%) according to humane endpoints. Animals showing such conditions were anesthetized and subsequently sacrificed in accordance with experimental protocols, which were reviewed and approved by the Animal Ethical Committee of The University of Trento and the Italian Ministry of Health. Five-week old CD1 female mice were immunized intraperitoneally (i.p.) on day 0, 14 and 28 with 10 μg of OMVs together with 2mg/ml Aluminium hydroxide in a final volume of 200 μl. Sera were collected 10 days after the last immunization. Alternatively, mice received intramuscularly (i.m.) 50 μl of AstraZeneca ChAdOx1 nCoV-19 vaccine, consisting in roughly 2.5x10⁷ infectious units.

Vaccination status was divided into three categories: non-vaccinated, partially vaccinated, and fully vaccinated. Patients with explicitly recorded missing vaccination against COVID-19 and a positive COVID-19 RT-PCR test result were defined as “non-vaccinated.” Patients with a record of only one vaccine dose or diagnosed with COVID-19 infection less than 14 days after receipt of the second vaccine dose were categorized as partially vaccinated. Patients with a positive COVID-19 RT-PCR test result/onset of symptoms at least 14 days after receipt of the second vaccine dose were defined as fully vaccinated. Patients with no record of missing or receiving vaccination, and patients with missing information on the last vaccination date were categorized as having “unknown vaccination status” and excluded from the study cohort. Regarding categorization, no difference was made between the varying vaccines (ChAdOx1 nCoV-19 vaccine-AstraZeneca, BNT162b2vaccine-Pfizer-BioNTech, mRNA-1273 vaccine-Moderna), with one exception. Patients who had received the Ad26.COV2.S vaccine-Johnson& Johnson-Janssen as the first vaccine, required a second dose with an mRNA vaccine at least 14 days before a positive COVID-19 RT-PCR test result/onset of symptoms.