Swine Flu
Swine flu refers to the H1N1 influenza strain that emerged as a pandemic in 2009. The name comes from the virus’s origins in pigs, though it spread between humans through the same routes as seasonal influenza: respiratory droplets from coughing, sneezing, and talking.
H1N1 and seasonal flu vaccination
Since the 2009 pandemic, the H1N1 strain has become part of the regular seasonal influenza landscape. Modern flu vaccines include protection against H1N1 strains as part of their formulation. This means that people who receive the annual flu vaccine are getting coverage for H1N1 along with the other circulating strains selected for that year.
The Australian Immunisation Handbook provides authoritative information on the composition of current flu vaccines and the strains they target.
Symptoms
H1N1 produces symptoms similar to other forms of influenza. As with seasonal flu, symptoms manifest within one to three days of exposure, and recovery can stretch over two weeks. The illness is generally indistinguishable from other influenza strains without laboratory testing.
Workplace vaccination
Because H1N1 is included in the annual flu vaccine, a standard workplace flu vaccination program provides protection against it alongside other influenza strains. There’s no need for a separate vaccine.
Australia’s flu season runs from April to October, with peak activity between June and September. Getting vaccinated early in the season provides the best protection across all included strains, including H1N1.
For more on influenza generally, see what is influenza. For information on potential complications, visit our flu complications page. To organise flu vaccination at your workplace, request a quote.
Last updated: 18 May 2026