Why is there no vacuum in the poultry freeze-dried vaccine bottle of Shihua Animal Health Company in France?

Doing so is conducive to preserving the quality of vaccines and further ensuring the interests of product users. As we all know, traditionally, the interior of freeze-dried vaccine bottles is generally in a "vacuum" state, which is why there is a slight sound of water being "sucked" into the bottles when the bottle stopper is opened under the water surface, or when the injection needle pierces the bottle stopper, it will feel attractive to the bottles. This "vacuum" state can be detected by a vacuum detector.

However, this "vacuum" state in the vaccine bottle has obvious disadvantages for maintaining the activity of the vaccine. The reason is that there is always a pressure difference of about one atmosphere inside and outside the vaccine bottle, which will lead to a small gap at the joint between the rubber stopper and the bottleneck, and in extreme cases, it may also lead to a small crack in the rubber stopper of the vaccine bottle itself. Once this happens, the outside air will be quickly sucked into the vaccine bottle, and the freeze-dried vaccine cake will accept harmful components in the air like a sponge, which will have a negative impact on the vaccine titer. For example, oxygen molecules in the air will "kill" vaccine viruses through oxidation; Water molecules in the air will increase the activity of hydrolytic protease in vaccine cake, degrade the protective agent in vaccine or directly "kill" vaccine virus; Mold spores in the air enter the vaccine bottle and pollute the vaccine.

In order to avoid the above situation, during the production of live poultry vaccine, CEVA SANTE ANIMALE Company of France filled a certain amount of nitrogen into the vaccine bottle in the later stage of freeze-drying process, that is, the bottle of its freeze-dried poultry vaccine was not in a "vacuum" state. The nitrogen filled in the vaccine bottle is sterile and dry inert gas, which is beneficial to keep the vaccine cake dry (the water residue of normal vaccine cake should not exceed 4%); Moreover, the vaccine protective agent and the virus itself will not be oxidized, which is conducive to maintaining the effective titer of the virus; Nitrogen will not destroy the "sterile" state in the vaccine bottle.