Research and analysis

Influenza A (H1N1v and H1N2v): incubation and infectious period

A rapid evidence summary identified and summarised evidence related to the incubation and infectious periods of influenza A (H1N1v and H1N2v).

• From: UK Health Security Agency
• Published: 17 October 2024
• Last updated: 3 December 2025 — See all updates

Documents

Incubation and infectious period of influenza A (H1N1v and H1N2v): a rapid evidence summary

Ref: Published October 2024 GOV-17336

PDF, 332 KB, 25 pages

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Details

This rapid evidence summary identified and summarised evidence related to the incubation and infectious periods of influenza A (search up to 27 November 2023).

Studies with laboratory-confirmed influenza A (H1 Swine; H1N1 or H1N2) that included any measure of the incubation or infectious periods of influenza A were eligible for inclusion.

Four retrospective and one prospective cohort study were included reporting the incubation period and infectious period of influenza A H1N1 variant (H1N1v). No studies were identified for the H1N2 variant (H1N2v).

Published 17 October 2024

Last updated 3 December 2025 + show all updates

1. 3 December 2025

   Updated the title to be more specific, and made a few minor updates to the wording of the details (for example, 'review' changes to 'summary').

2. 17 October 2024

   First published.