FDA drops a hepatitis B blood test where two others are run

The Food and Drug Administration has finalised guidance telling blood collectors they no longer need to run one of the long-standing hepatitis B tests on most blood donations, provided two other tests are performed. The guidance, "Recommendations for Reducing the Risk of Transfusion-Transmitted Hepatitis B Virus," was announced in the Federal Register on 3 November 2026 under docket number FDA-2024-D-5942 [s1].

The change in testing

Blood establishments have historically screened donations for hepatitis B surface antigen, or HBsAg, a marker of active infection. The FDA now says that step is not always necessary. Where donations are tested for hepatitis B virus DNA by nucleic acid tests, known as NAT, and for antibody to hepatitis B core antigen, known as anti-HBc, using screening tests the FDA has licensed, approved or cleared and used according to the manufacturer's instructions, "testing for HBsAg is not necessary to reduce adequately and appropriately the risk of transmission of HBV" [s1].

That recommendation applies to the collection of whole blood and blood components. The agency draws a clear exception for Source Plasma — plasma collected for further manufacturing into medicines. For Source Plasma donations, the FDA writes, "we continue to recommend that testing for HBsAg and HBV DNA by NAT is necessary" to reduce the risk of transmission adequately and appropriately [s1]. The guidance covers donation testing, donor deferral and the requalification of deferred donors, as well as product management, retrieval and quarantine [s1].

The two tests the FDA is leaning on detect the virus in different ways. Nucleic acid testing looks for hepatitis B viral DNA directly, while the anti-HBc test detects the body's antibody to the virus's core antigen, a marker that can persist after an infection. The surface-antigen test the agency is setting aside for whole-blood donations detects a protein on the surface of the virus. In the FDA's assessment, where both the DNA and antibody tests are already performed with authorised assays, adding the surface-antigen test does not meaningfully further reduce the risk of transmission for those donations [s1]. Alongside the testing change, the guidance makes conforming changes for donor requalification and for the labelling of units [s1].

Consolidating decades of memoranda

A large part of what this document does is housekeeping. The FDA says it consolidates recommendations on testing blood for hepatitis B that had been issued across numerous separate memoranda and guidance documents over several decades [s1]. The final guidance supersedes prior documents dating back to a December 1987 memorandum, along with documents from 1991, 2007, 2010, 2011 and 2012, and the HBV-specific parts of a July 1996 memorandum [s1]. In pulling them together, the agency says it made minor changes to reflect advances in the tests used to screen donations and to align with current practices [s1].

From draft to final

The guidance finalises a draft the FDA issued on 16 July 2025, which had been titled "Recommendations for Testing Blood Donations for Hepatitis B Surface Antigen" [s1]. The agency says it received several comments on that draft and considered them, and that the editorial changes between draft and final were made to improve clarity [s1]. The retitling reflects the broader scope of the final document, which now addresses reducing transmission risk overall rather than one antigen test.

The legal weight

As with other FDA guidance, this document is not a binding rule. The agency states it is being issued consistent with its good guidance practices regulation and "represents the current thinking of FDA" on the subject [s1]. It "does not establish any rights for any person and is not binding on FDA or the public," and a blood establishment "can use an alternative approach if it satisfies the requirements of the applicable statutes and regulations" [s1]. Comments may be submitted at any time [s1].

What is settled

What is fixed by this action is that a single, dated final guidance now replaces a scattered set of older instructions, and that it sets out when HBsAg testing can be dropped for whole blood and components and when it must continue for Source Plasma [s1]. The practical effect for blood establishments is a simpler testing algorithm that leans on the more sensitive nucleic-acid and anti-core tests, while the stricter regime is retained for the plasma that becomes injectable medicines [s1]. The guidance is available through the FDA's biologics guidance pages and on the federal rulemaking portal [s1].