[Effects of subunit influenza vaccines in a mouse model of asthma]

To explore the effects of subunit influenza vaccines on mouse model of asthma.

Six-week-old female BALB/c mice were randomly divided into PBS control group, asthma control group and subunit influenza vaccine group. Mice in the asthma control group and the subunit influenza vaccine group were sensitized on the 0, 7th, 14th day by intraperitoneal injection of 50 μg ovalbumin (OVA) emulsified in 2 mg aluminum hydroxide. The PBS control animals were given an equal volume of PBS. The mice in the subunit influenza vaccine group were immunized intramuscularly with 0.1 mL subunit influenza vaccines on the 21st day, and were boosted intranasally with 40 μL vaccines on the 28th day. Subsequently, the mice in the asthma control group and the subunit influenza vaccine group were exposed to OVA aerosol challenge for 3 consecutive days (the 42nd, 43rd, 44th day). Within 48 hours after the last challenge, all mice were sacrificed after the blood was obtained, and the bronchoalveolar lavage fluid (BALF) samples were collected for cell counting and classification. Lung tissues were prepared and HE staining and PAS staining were used to evaluate pulmonary inflammation and mucus production. IgE levels in sera and interleukine 4 (IL-4), IL-5, IL-13, interferon γ (IFN-γ) levels in BALF were measured by ELISA.

Compared with the PBS control group, the pulmonary inflammation and mucus production significantly increased in the asthma control group and the subunit influenza vaccine group, and the levels of IL-4, IL-5, IL-13, IFN-γ in BALF and serum IgE were also significantly elevated. However, no significant difference was found between the subunit influenza vaccine group and the asthma control group.

In mouse model of asthma, the use of subunit influenza vaccine does not exacerbate asthma symptoms, and is relatively safe.