In the defense line for safeguarding human health, human vaccines play an irreplaceable and crucial role. Behind the production of every safe and effective vaccine, the environmental quality of the purification workshop is of vital importance. Especially the two core elements, namely cleanliness and airflow ventilation in the workshop, are just like the "calibration parameters" of precision instruments and allow no slightest negligence.

Human vaccines are related to lives. Tiny impurities and microorganisms can become "destructive elements", reducing the efficacy of vaccines or even causing serious side effects. Therefore, extremely high cleanliness is the primary standard for purification workshops.

Internationally, the mainstream standards divide cleanroom levels according to ISO 14644. The core areas of human vaccine production mostly require reaching ISO 5 level or even the higher ISO 4 level of cleanliness. In an ISO 5 level environment, the number of dust particles with a size equal to or greater than 0.5 micrometers in each cubic meter of air is limited to no more than 3,520. Such strict control is only to "intercept" dust, prevent bacteria and viruses from attaching as "hitchhikers", and reduce the risk of contamination. From the receipt of raw materials, formulation, to the processing of semi-finished products and the filling of finished products, each link has "increasingly strict protection" for cleanliness. For example, in the formulation area, when the solution is precisely prepared, an almost "spotless" space ensures the purity of raw materials and prevents foreign substances from mixing in to change the vaccine formula and affect its immunogenicity. In the filling area, the cleanliness is directly related to the sterility guarantee of finished products. Before the products are sealed and packaged, the pure environment safeguards the vaccines to be "ready for delivery".

Reasonable airflow organization and an efficient ventilation system are the "vitality" of the vaccine purification workshop, maintaining the indoor air to be always "fresh and compliant".

The airflow in the workshop mostly adopts a combination design of unidirectional flow and non-unidirectional flow. The unidirectional flow is like an "air waterfall". At key operation points (such as the aseptic filling line), it has a vertical or horizontal laminar flow, "flushing" the working area at a stable and uniform flow rate, continuously taking away the particles and microorganisms emitted by personnel and equipment, just like an "aseptic cover" enveloping the operation process. The non-unidirectional flow is suitable for auxiliary areas such as storage and passages. After being filtered by high-efficiency filters, the air is circulated according to specific ventilation frequencies to dilute the concentration of pollutants.

The ventilation frequency is "tailored" according to the cleanliness level of the workshop. In an ISO 5 level workshop, the ventilation usually reaches 20 to 30 times per hour. The high-frequency ventilation is like "metabolism", quickly discharging aerosols, dust, etc. that may mix in, replenishing purified fresh air, balancing the temperature and humidity, and stably controlling the growth of microorganisms. In special process links, such as the live virus treatment area, the ventilation frequency will be further "increased", and combined with a negative pressure design to ensure that the air only enters but does not exit and prevent diffusion, thus ensuring the safe isolation of the internal and external environments.

Cleanliness and airflow ventilation are not something that can be left alone after being set up. Daily operation and maintenance are the "key to continuous operation". Regular replacement of filters (high-efficiency filters are usually replaced once every 1 to 2 years depending on the usage intensity and resistance changes), cleaning and disinfection of equipment (thorough cleaning after each shift and fumigation sterilization every week), and real-time monitoring of air quality (with particle counters and airborne microorganism samplers on duty) are all carried out simultaneously. The standardized management of personnel is also indispensable. Personnel can enter the workshop only after going through a strict purification process for dressing and training, and their movements and action ranges are restricted to reduce human interference. From hardware to software, everything is "seamlessly connected", making the vaccine purification workshop a stable and reliable "cradle of life", nurturing high-quality vaccines that safeguard the health of the public.

In the frontier of biopharmaceutical manufacturing, the cleanliness and airflow ventilation in human vaccine purification workshops, with precision down to the slightest detail and persistent operation and maintenance, lay a solid foundation for the global immunization defense line. They are "meticulously crafted" in the microscopic world to safeguard the purity and efficacy of each dose of vaccine and give life the "confidence" to resist diseases.