Which 2025 influenza vaccine formulations are offered in single-dose vials or prefilled syringes?

1. Policy pivot: single‑dose, thimerosal‑free now the official preference

The Advisory Committee on Immunization Practices (ACIP) adopted a new recommendation in 2025 that children ≤18 years, pregnant women and all adults receive seasonal influenza vaccines only in single‑dose formulations that are free of thimerosal as a preservative; CDC reiterates that recommendation for the 2025–2026 season ^{[2] [1]}. HHS subsequently adopted the ACIP recommendation in a public announcement ^[8].

2. What “single‑dose” covers: prefilled syringes and single‑use vials

Public guidance uses the term “single‑dose formulations” to mean both prefilled syringes (PFS) and single‑use vials; dosing guidance and package inserts routinely list prefilled syringes and single‑dose vials as preservative‑free options ^{[9] [10] [1]}. CDC and FDA materials note that multi‑dose vials, when still produced, typically contain thimerosal, while the single‑dose formats do not ^{[9] [11]}.

3. Which brand products are explicitly offered as prefilled syringes or single‑dose vials

Manufacturer and distributor pages and product inserts for 2025 products list multiple single‑dose PFS presentations: GSK’s Fluarix and Flulaval are available as 0.5‑mL single‑dose prefilled syringes ^{[3] [4]}; Seqirus/Fluad is supplied in 0.5‑mL prefilled syringes without preservative for older adults ^[5]; Seqirus/Flucelvax TIV is sold in prefilled syringe packs ^[6]; Flublok is marketed in prefilled syringe presentations on supplier catalogs ^[7]. Product inserts confirm Flucelvax 0.5‑mL prefilled syringes contain no preservative ^[11].

4. Practical supply landscape: most doses expected preservative‑free but MDVs may persist

CDC and industry reporting project a predominantly single‑dose supply for U.S. providers in 2025–2026 and note most vaccines will be preservative‑free, though multi‑dose vials (MDVs) containing thimerosal might still be manufactured and could be available in limited amounts ^{[1] [12] [13]}. Some state guidance and clinical dosage charts warn MDV presentations might remain and that ACIP prefers single‑dose use ^[13].

5. Tradeoffs and controversies around the shift

Public health documents and commentary lay out competing views: ACIP’s move is framed as reducing theoretical cumulative exposure to thimerosal ^{[2] [1]}, while clinical resources point out that large studies have not shown harm from low thimerosal doses and that discouraging MDVs could increase costs or constrain access, especially in settings that rely on MDVs for logistical reasons ^{[14] [15]}. CIDRAP coverage and Pharmacist’s Letter emphasize that the recommendation is policy‑driven, not driven by new evidence of harm ^{[15] [14]}.

6. If you need a specific list for procurement or clinics

Available product pages and distributor listings in current reporting identify Fluarix, Flulaval, Flucelvax (cell‑based), Fluad (adjuvanted for ≥65), Flublok (recombinant) and Afluria among vaccines sold in prefilled syringe formats for 2025 presentations ^{[3] [4] [6] [5] [7]}. For single‑use vials, product inserts and CDC dosing guidance name single‑dose vials for several licensed IIVs ^{[10] [9]}. Providers should consult manufacturer product inserts and supplier catalogs for exact NDCs, age indications and pack sizes before ordering ^{[3] [10]}.

7. Limitations and next steps for readers and buyers

This analysis is based on CDC, ACIP and manufacturer materials and distributor product listings cited above; it does not assert the complete market inventory of every formulation by every manufacturer because availability can change as manufacturers ship and retailers list products—those changes are not exhaustively detailed in the cited sources ^{[1] [6] [5]}. For procurement decisions, cross‑check current FDA‑licensed product labeling and supplier stock lists and confirm whether any MDVs remain in your supply chain ^{[10] [3]}.

Bottom line: federal guidance and manufacturer product information confirm wide availability of single‑dose, thimerosal‑free influenza vaccines in prefilled syringes and single‑use vials for 2025–2026, with named brands (Fluarix, Flulaval, Flucelvax, Fluad, Flublok, Afluria) explicitly listed in supplier and product documentation ^{[1] [2] [3] [4] [6] [5]}.