The recent appearance of the H5N1 bird flu in pigs does raise viral reassortment concerns. Here's what we know about this highly pathogenic avian influenza virus so far.

The developing avian influenza panzootic and the growing possibility of a pandemic bring to the fore the existential questions for humanity of climate change and the destruction of public health, both of which must be stopped in order to control the growing threats.

Human cases in the US are on the rise and the virus is turning up in cows and dairy products. Luckily, we have some vaccines ready to go if needed.

In the 2009 swine flu pandemic, multiple reassortment events in pigs and birds led to the novel H1N1 virus strain, which led to 60 million cases and 12,000 deaths in the U.S. in its first year of circulating, per the CDC .

In June, CSL Seqirus received an order for 665,000 pre-pandemic bird flu vaccines from the European Commission that will be used across 15 EU member states. The four-year contract included an option for the purchase of up to an additional 40 million doses.

The UK has secured a contract for more than five million doses of a bird flu vaccine, to be used if the H5N1 strain spreads among humans, as part of preparations for any possible influenza pandemic. The UKHSA says at this stage there is no evidence of human-to-human transmission.

H5N1 bird flu is spreading among animals and humans, raising concerns about mutation risks. While human cases are mild, experts stress urgent preparedness for potential pandemics and vaccine readiness gaps.

Bird flu vaccine deal agreed to bolster pandemic preparedness - The UK Health Security Agency stressed there is no evidence at this stage to suggest the A(H5N1) virus will start spreading among humans.