Optimization of Heat-Resistance Technology for a Duck Hepatitis Lyophilized Live Vaccine

Abstract

In this study, to improve the quality of a live attenuated vaccine for duck viral hepatitis (DHV), the lyophilization of a heat-resistant duck hepatitis virus vaccine was optimized. The optimized heat protectors were made of 10% sucrose, 1.2% pullulan, 0.5% PVP, and 1% arginine, etc., with a titer freeze-drying loss of ≤0.50 Lg. The vaccine product’s valence measurements demonstrated the following: the vaccine could be stored at 2–8 °C for 18 months with a virus titer loss ≤0.91 Lg; at 37 °C for 10 days with a virus valence loss ≤0.89 Lg; and at 45 °C for 3 days with a virus titer loss ≤0.90 Lg. Regarding safety, no deaths occurred in two-day-old ducklings immunized with a 10 times dose vaccine; their energy, diet, and weight gain were all normal, demonstrating that the DHV heat-resistant vaccines were safe for ducklings and did not cause any immune side effects. Duck viral hepatitis freeze-dried vaccine began to produce antibodies at 7 d after immunization, reached above 5.0 on 14 d, and reached above 7.0 on 21 d, showing a continuous upward trend. This indicates that duck viral hepatitis vaccine has a good immunogen level. The optimization of the freeze-drying process saves costs and also improves the quality of the freeze-drying products, which provides important theoretical and technical support for the further study of vaccine products.

Freeze-drying for the preservation of immunoengineering products

“…The optimized heat protectors were made of a mixture of 10% sucrose, 1.2% pullulan, 0.5% PVP, and 1% arginine to develop safe and cost-effective vaccine formulation with short time lyophilization cycle. The lyophilized cake formulation with SEM image has shown similar porous honey comb like structure which is similar to commercial formulation ( Figure 7 ) ( Zhao et al., 2022 ).

Figure 7 SEM image for hepatitis lyophilized live vaccine A Commercial formulation B. in house formulation both are with porous honeycomb like morphology ( Zhao et al., 2022 ), this image was obtained from open access journal Vaccines MDPI: https://doi.org/10.3390/vaccines10020269 .

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“… Commercial formulation B. in house formulation both are with porous honeycomb like morphology ( Zhao et al., 2022 ), this image was obtained from open access journal Vaccines MDPI: https://doi.org/10.3390/vaccines10020269 . …”

Screening and Stability Evaluation of Freeze-Dried Protective Agents for a Live Recombinant Pseudorabies Virus Vaccine

“…In addition to virus titration, SEM, XRD and FTIR have been widely used to evaluate heat-resistant freeze-dried formulations [ 24 , 37 ]. SEM results reveal that the A4-formulation vaccine exhibits a honeycomb-like porous structure, with trehalose and gelatin aiding the formation of a skeleton during freeze-drying.…”

“…Additionally, the porous structure aids in the swift recovery of biological activity upon vaccine reconstitution. The protectant freeze-drying process serves a dual purpose of preserving the vaccine’s biological activity and acting as an excipient [ 24 ]. X-ray diffraction (XRD) investigations showed that the freeze-dried vaccine was an amorphous material.…”

“…In this study, heat-resistant freeze-dried formulations of the recombinant PRV rHN1201 TK−/gE−/gI−/11k−/28k− strain was studied. Ten different lyophilization protectants were designed, including trehalose, gelatin, thiourea, sorbitol, and polyvinylpyrrolidone (PVP), all of which have been shown to ensure the stability of live vaccines during lyophilization and storage [ 22 , 23 , 24 ]. Optimal combinations were screened using lyophilization and heat loss.…”