immunology - Allergic rhinitis vaccine

Note : Any answer to this question will not be (and should not be) taken as medical advice.

One of my friends has allergic rhinitis and has been prescribed an oral vaccine. He is allergic to 3 different classes of substances and so, has been given 3 different types of vaccines. He has to place them below his tongue.

I am curious about some of the procedures he has to follow.

1.How does a vaccine of this type work ?

2 He has been given 2 vials for each type of vaccine. First one is labeled SRS and other one as I understand is - it's allergen. So, What is SRS ? What's the requirement of it ?

3 It is written in the instructions that he should not eat anything one hour before and one hour after taking the vaccine. Why ?

Answer

Rhinitis is irritation and inflammation of the mucous membrane inside the nose. Common symptoms of rhinitis are a stuffy nose, runny nose, and post-nasal drip. The most common kind of rhinitis is allergic rhinitis, which is usually triggered by airborne allergens such as pollen and dander ^[1].

Many questions regarding sublingual immunization still remain to be addressed, including the use of proper adjuvant and the optimization of vaccine formulation to further enhance the vaccine efficacy ^[2].

Sublingual immunization can induce both systemic and mucosal immune responses against a variety of antigens, including soluble proteins, inter particulate antigens, and live-attenuated viruses ^[2].

Sublingual immunization has been shown to be safe and highly effective in generating robust immune responses against the administered antigen. Moreover, it has been shown to confer protective immunity by simultaneously eliciting systemic IgG and mucosal IgA antibodies as well as cytotoxic T lymphocyte responses in the peripheral lymphoid organs and mucosal tissues. Studies also suggest that sublingual immunization could be a better alternative to the traditional parental route of vaccine delivery against both genital and respiratory pathogens ^[2].

Although the s.l. mucosa does not allow passage of macromolecules into blood, s.l. immunization with ovalbumin, a model soluble protein antigen, administered alone or together with cholera toxin adjuvant, induces mucosal antibody responses as well as systemic immune responses in mice. The magnitude of serum antibody responses induced by s.l. immunization was in fact comparable to that seen after intranasal (i.n.) immunization and far superior to that after o.g. (oro-gastric) immunization ^[3].

Upon stimulation of mucosal surfaces by foreign antigens, dendritic cells among the antigen presenting cells are immediately processed and transport antigen via afferent lymph to draining lymph node for presentation to T cells. Subsequently they induce secretory IgA antibodies. This suggestive link between trafic pattern of dendritic cells and their functions led to the investigation of the chemokine responsiveness of dendritic cells during their development and maturation. It has been observed that type II mucosa tissues (e.g., skin, vaginal, and buccal), which are covered with stratified epithelia and devoid of mucosa-associated lymphoid tissues, mainly express CCL20, CCL19/CCL21, or CCL27/CCL28 individually ^[4].

CCR7 (chemokine receptor) expressed CD8α^-CD11c⁺ cells ferry antigens in the sublingual mucosa, migrate into the cervical lymph nodes, and share the antigen with resident CD8α⁺CD11c⁺ cells for the initiation of antigen-specific T and B cell responses following sublingual challenge. The sublingual mucosa is one of the effective mucosal inductive sites regulated by the CCR7-CCL19/CCL21 pathway ^[4].

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References:

1. Wikipedia, Rhinitis


2. Byoung-Shik Shim, Youngjoo Choi, In Su Cheon, and Man Ki Song. Sublingual Delivery of Vaccines for the Induction of Mucosal Immunity.


3. Cecil Czerkinsky, Nicolas Çuburu, Mi-Na Kweon, Fabienne Anjuere and Jan Holmgren. Sublingual vaccination.


4. Joo-Hye Song, Jung-Im Kim, Hyung-Joon Kwon, Doo-Hee Shim, Nirmala Parajuli, Nicolas Cuburu, Cecil Czerkinsky and Mi-Na Kweon. CCR7-CCL19/CCL21-Regulated Dendritic Cells Are Responsible for Effectiveness of Sublingual Vaccination.