“Swine flu” is an obsolete name. The official name for the virus that was briefly called “swine flu” is “H1N1pdm09”.
H1N1pdm09 has a mortality rate of around 0.01-0.1%. That’s roughly 10- to 20-fold lower than COVID-19. Its R0 was estimated at between 1 and 2, which is roughly half the estimates for SARS-CoV-2 (the virus responsible for COVID-19].
A vaccine for H1N1pdm09 was available in the fall of 2010. It was possible to make it that quickly because it’s just another influenza strain, and the normal techniques for for vaccines against influenza strains worked fine.
Most importantly, H1N1pdm09 never went away. It is still one of the main influenza strains circulating today, and if you were vaccinated for influenza since 2010 you received a vaccine against it.