Allergy serum, or allergen immunotherapy, modifies the body’s immune response to specific allergens. Treatment involves administering gradually increasing doses of the substance (such as pollen, mold, or pet dander) to desensitize the immune system. The goal is to induce long-term tolerance, reducing or eliminating allergy symptoms. Proper storage is mandated to maintain the integrity of these active biological components, ensuring the treatment remains effective and safe.
Why Refrigeration is Required
The active ingredients in allergy serum are proteins and glycoproteins extracted from the source allergen. These biological molecules are highly susceptible to denaturation and degradation when exposed to elevated temperatures. Refrigeration significantly slows down the chemical reactions that break down these complex protein structures, preserving the serum’s therapeutic activity.
Heat exposure accelerates this deterioration, causing the active allergen components to lose their original structure and biological potency. Storing the extract at the recommended temperature, typically $2^{\circ}\text{C}$ to $8^{\circ}\text{C}$ ($36^{\circ}\text{F}$ to $46^{\circ}\text{F}$), reduces the rate of potency loss. This cold environment maintains the integrity of the allergen proteins, ensuring the administered dose contains the expected amount of active substance.
Maximum Time and Temperature Limits
Guidelines for unrefrigerated exposure vary considerably, requiring consultation with the specific product information or prescribing physician. The ideal storage condition is continuous refrigeration at $2^{\circ}\text{C}$ to $8^{\circ}\text{C}$, which reduces the rate of potency loss over the long term.
For brief excursions, such as during transport, many manufacturers provide generalized limits. Clinics often advise that a serum vial may be safe for one to two hours at normal room temperature ($20^{\circ}\text{C}$ to $25^{\circ}\text{C}$). Extracts stabilized with 50% glycerin have demonstrated greater tolerance, sometimes retaining potency for at least a week at room temperature. Any time outside of refrigeration is cumulative, and the specific allergen and concentration influence the precise stability window.
Consequences of Improper Storage
Exceeding the recommended time and temperature limits results primarily in the loss of the serum’s efficacy. As the allergen proteins degrade, the overall potency of the treatment decreases, leading to an ineffective dose. This loss of potency can slow or halt the process of desensitization.
Improper storage can also introduce potential safety risks. Degradation of the protein structure can alter the serum’s composition, potentially changing how the immune system reacts to the injection. This structural change could increase the risk of adverse reactions, such as localized swelling or a systemic response. Cold storage ensures the treatment is effective, predictable, and safe for administration.
What to Do If the Serum Was Left Out
If allergy serum has been left unrefrigerated, the immediate first step is documenting the details of the exposure. Record the exact duration the vial was out of the refrigerator and the best estimate of the ambient temperature. This information is necessary for your healthcare provider to make an informed decision about the vial’s usability.
Next, visually inspect the serum for any signs of physical change. The liquid should be clear and free of cloudiness, discoloration, or particulate matter. If the serum appears visibly altered, it must not be used, though potency may still be compromised even if it looks normal. Contact the prescribing physician or clinic immediately, reporting the duration and temperature of the exposure, as disposal should only happen under their direction.