无针皮内注射免疫甲型H7N9流感裂解疫苗的免疫效果评价

Immunoprotection induced by recombinant H7N9 split vaccine operated by a needle-free intradermal injection

目的开展无针皮内注射免疫甲型H7N9裂解流感疫苗的安全性及有效性评价,为无针注射免疫疫苗提供实验依据。方法采用无针皮内注射H7N9裂解流感疫苗免疫小鼠和大鼠,并用有针肌肉注射免疫做对照,通过活体成像技术观察疫苗的分布情况,并采用血疑抑制试验测定疫苗免疫后的血清中和抗体效价、滴鼻攻毒评价免疫保护及DRAIZE评分与病理检测注射损伤情况。结果无针皮内注射免疫疫苗在真皮内呈池状分布,且疫苗驻留时间明显长于在肌肉层的驻留时间。无针皮内免疫3μg抗原的甲型H7N9流感裂解疫苗可起到肌肉免疫15μg抗原的同样血清学保护水平及免疫保护效果。结论无针皮内注射免疫甲型H7N9裂解流感疫苗安全、有效,且抗原用量是有针肌肉注射免疫抗原用量的1/5量,将为流感疫苗免疫防控提供新的技术策略。

This study designed to evaluate the safety and the immune efficacy of the recombinant H7N9 split vaccine operated by a needle-free intradermal injection, providing the experimental evidence for needle free injection vaccines. The 7-day-term in vivo images were acquired by the Kodak In vivo Imaging System FX PRO, in order to track the antigen distribution processes after i.d. and i.m. vaccination. To compare immunogenicity and efficacy of different immunization methods, the hemagglutination-inhibition （HI） antibody titers in serum were measured. The cutaneous damages caused by intramuscular and intradermal injection were examined for evaluating skin irritation and pathology. The intradermal injection caused a pool-like diffusion spread of the antigen and stimulated longer serum protection. A needle-free intradermal immunization dose of 3 p,g HTN9 influenza vaccine could induce effective protection, compared to an intramuscular immunization. The results reveal that an intradermal immunization with the H7N9 influenza vaccine is safe and effective, and even 20% dose of the antigen could protect mice from a lethal challenge.