As autumn arrives, influenza prevention is once again in focus. According to surveillance data from the Chinese Center for Disease Control and Prevention (China CDC), from August 31 to September 6, 2026, influenza-like illness accounted for 3.8% of outpatient and emergency visits at sentinel hospitals nationwide, with 4.6% in southern provinces and 2.9% in northern provinces, indicating a slight recent increase in influenza activity. During the same period, data from the National Influenza Center showed that influenza A accounted for 67.1% of positive influenza samples, while influenza B accounted for 32.9%.
Ahead of the influenza season, personal protection and vaccination remain important measures for reducing health risks. However, traditional intramuscular injections can make children feel nervous or reluctant to get vaccinated. With advances in vaccine technology and drug delivery, nasal spray flu vaccines offer an alternative vaccination method for eligible children—no needles, just nasal delivery. So, how does a nasal spray flu vaccine work? And how does this small nasal spray device deliver the vaccine accurately into the nasal cavity?
What is a nasal spray flu vaccine?
The nasal spray flu vaccine currently used in China is Ganwu®, developed by Changchun Bcht Biotechnology, officially known as the Live Attenuated Influenza Vaccine (LAIV).
Unlike traditional inactivated influenza vaccines, which are administered by intramuscular injection, nasal spray flu vaccines are delivered through the nasal mucosa.
Simply put:
· Injection: The vaccine is delivered into the muscle through a needle.
· Nasal spray: The vaccine is delivered through the nasal cavity to the respiratory mucosa.
Influenza viruses are primarily transmitted through the respiratory tract, making the nasal cavity an important “entry point” for the virus.
In live attenuated influenza vaccines, the virus is attenuated and designed with cold-adapted and temperature-sensitive characteristics. It undergoes limited replication mainly in the relatively cooler environment of the nasal cavity, where it interacts with the nasal mucosa and immune system to induce an immune response.
So, nasal vaccination is not simply about replacing a “needle” with a “spray.” It uses a different delivery route and immune pathway. And no needle does not mean reduced protection.
The protective effect of a nasal spray flu vaccine comes from its validated vaccine formulation and immune mechanisms—not from the act of injection itself. By targeting the nasal mucosa, it can induce multiple layers of immune responses, including mucosal, humoral, and cellular immunity.
You may wonder:
“After being sprayed into the nose, is the vaccine absorbed into the bloodstream?”
Not exactly.
A nasal spray device uses a precision spray mechanism to turn the pre-filled vaccine solution into fine droplets and deliver them to the nasal mucosa.
The process can be summarized in five steps:
① Vaccine storage
The vaccine is pre-filled and sealed inside the device.
② Actuation
Pressing the device pushes the vaccine solution toward the spray mechanism.
③ Atomization
The liquid is converted into fine droplets suitable for nasal delivery.
④ Nasal deposition
The droplets enter the nasal cavity and contact the nasal mucosa.
⑤ Immune response
For LAIV, the attenuated virus undergoes limited local replication and interacts with the nasal mucosal immune system, triggering an immune response.
So, a nasal spray device does more than simply “spray the vaccine.” It converts the vaccine from a stable stored formulation into a suitable spray and delivers it to the target site.
That is why spray performance, dose control, and sealing integrity are all important to the delivery process.
Innovation in nasal spray flu vaccines lies not only in the vaccine itself, but also in the delivery device.
For vaccine and drug delivery applications, NEST has developed a prefilled nasal spray device that combines drug storage and administration, providing device support for nasal delivery.
01 Prefilled Design | Convenient Storage and Use
The drug solution is pre-filled and sealed in advance, reducing handling steps. Reliable sealing helps support stable storage and transportation.
02 Precision Spray | Effective Drug Delivery
A precision spray mechanism converts the drug solution into droplets suitable for nasal delivery, while the device design helps control the delivered dose for consistent administration.
03 Single Use | Simplified Administration
The single-use design eliminates the need for cleaning or reuse after administration, simplifying the end-user process.
04 R&D Progress | CDE Registration Status Updated to “A”
For nasal spray vaccines, the process can be understood simply:
The vaccine generates the immune response.
The nasal spray device enables stable and accurate delivery.
Together, they form an integrated nasal drug delivery system.
From traditional injection to nasal delivery, the change is not just in how vaccines are administered, but also in how they enter the body.
For children, nasal delivery can help reduce the pain and anxiety associated with traditional injections.
For the administration process, a prefilled design can help reduce handling steps.
For both the vaccine and the delivery device, however, it requires careful design and control of materials, container closure, dose accuracy, and spray performance.
What looks like a simple “spray” actually connects:
Vaccine Formulation × Prefilled Storage × Precision Atomization × Nasal Delivery × Immune Response
NEST continues to focus on vaccine and drug delivery, leveraging its established capabilities in medical device R&D and manufacturing to support innovative drug delivery approaches.
As influenza activity enters its seasonal phase, influenza prevention in children is once again drawing attention.
From “injecting” to “spraying,” drug delivery options continue to evolve.
A small nasal spray device bridges the final step between the vaccine and the human body.
Stable storage.
Precise delivery.
Reliable administration of innovative vaccines.
NEST — Supporting Innovative Drug Delivery with Reliable Devices.
