How To Reconstitute Rsv Vaccine Arexvy Abrysvo?

Reconstituting the RSV vaccines Arexvy and Abrysvo is a specific, step-by-step process that must be followed exactly to ensure the vaccine is safe and effective. For Arexvy, you must inject the entire contents of the accompanying diluent vial into the powder vial, gently swirl, and use it within 60 minutes. For Abrysvo, the vaccine comes as a ready-to-use liquid that does not require mixing, though it must be gently swirled before drawing the dose. The precise instructions for both vaccines are printed in the package insert, and only a trained healthcare professional should perform the reconstitution.

What Is the Exact Reconstitution Process for Arexvy?

Arexvy is supplied as two separate vials: one containing a white powder (the antigen) and one containing a liquid diluent. The powder must be mixed with the diluent before injection. This is a two-step process that requires care and attention to detail.

First, remove the plastic flip-off caps from both vials and clean the rubber stoppers with a sterile alcohol swab. Using a sterile syringe and needle, withdraw the entire contents of the diluent vial. Slowly inject all of the diluent into the vial containing the powder. Do not discard any of the diluent — the full volume is required for a proper concentration.

Second, gently swirl the vial until the powder is completely dissolved. Do not shake it vigorously. Shaking can create foam or bubbles, which can affect the dose you draw up. The final solution should appear clear and colorless to slightly yellow. If you see any particles or discoloration, do not use the vaccine. Once mixed, Arexvy must be administered within 60 minutes. Do not store the reconstituted vaccine for later use.

Does Abrysvo Require Reconstitution?

No. Abrysvo is manufactured as a sterile liquid that is ready to use. It does not come with a powder or a diluent vial. This is a key difference between the two RSV vaccines and a common source of confusion.

Before drawing the dose, gently swirl the Abrysvo vial. Do not shake it. The liquid should appear clear and colorless. If you notice any particulate matter or a change in color, discard the vial. Once the dose is drawn into a syringe, it should be administered promptly. The vaccine does not need to be diluted or mixed with anything else.

What Equipment Do You Need for Arexvy Reconstitution?

You will need the two vials included in the Arexvy carton, a sterile syringe with a needle, and alcohol swabs. The syringe must be large enough to hold the full volume of the diluent, which is 0.5 mL. Use a separate sterile needle to withdraw the diluent and to administer the vaccine if needed.

Check the expiration dates on both vials before you begin. If either vial is expired, do not use it. Also inspect both vials for damage. A cracked vial or a loose stopper means the product is compromised and must be discarded. All vaccine preparation should be done in a clean, designated area with proper hand hygiene.

How Should the Reconstituted Arexvy Be Stored?

Reconstituted Arexvy must not be frozen or refrigerated. It should be kept at room temperature and used within 60 minutes of mixing. If 60 minutes pass and the vaccine has not been used, it must be discarded. Do not return it to the refrigerator.

The unreconstituted vials — the powder and the diluent separately — should be stored in the refrigerator between 2°C and 8°C (36°F to 46°F). Protect them from light. Keep them in the original carton until you are ready to use them. Never freeze the powder or the diluent. Freezing can damage the vaccine components and make it ineffective.

What Are the Key Differences Between Arexvy and Abrysvo?

Beyond the reconstitution step, the two vaccines have some important differences in formulation and administration. Arexvy contains an adjuvant, which is an ingredient that helps create a stronger immune response. Abrysvo does not contain an adjuvant. This is why Arexvy requires the two-vial system with a powder and liquid, while Abrysvo is a single liquid vial.

Both vaccines are given as a single intramuscular injection, typically in the deltoid muscle of the upper arm. The dose volume for both is 0.5 mL. The most common side effects for both include injection site pain, fatigue, muscle aches, and headache. These are generally mild and resolve within a few days.

Neither vaccine is approved for primary immunization of infants. Both are approved for use in older adults. Arexvy is also approved for use in pregnant people to protect infants from birth through six months of age, though the specific recommendations and availability can vary. Always confirm the current approved indications and recommendations at the time of administration.

What Mistakes Should You Avoid During Reconstitution?

The most common errors involve incorrect mixing technique and timing. Using less than the full volume of diluent will result in an incorrect concentration and an ineffective dose. Shaking the vial vigorously instead of swirling can create air bubbles, which make it difficult to draw the correct volume into the syringe.

Another frequent mistake is using the wrong diluent. Arexvy must only be mixed with the diluent supplied in the same carton. Do not substitute saline or sterile water. Using the wrong liquid can damage the vaccine or change its potency. Never combine the contents of two different vaccine vials. Each vial is a single dose.

Finally, do not attempt to split a reconstituted vial between two patients. Each vial contains exactly one 0.5 mL dose. Attempting to split doses can lead to underdosing and is a serious medication error.