Swine flu reoccurrence? can someone get swine flu twice?

The : The influenza virus is a respiratory virus that affects humans, pigs, birds and poultry. It is a constantly changing virus by virtue of the fact that it makes continuous small changes (mutations) to its genetic make-up. Sometimes, mutations result in a much more dramatic recombination of genes, leading to a "new" strain. This phenomenon is called "antigenic shift". The pandemic that began in march 2009, commonly referred to as "swine flu", was caused by a h1n1 influenza a virus. This arose from the quadruple re-assortment of two swine strains, one human strain, and one avian strain of influenza; the largest proportion of genes comes from swine influenza viruses hence its name. The reason that this is important is that once you are infected with a specific strain, your immune system will develop antibodies towards that strain and prevent re-infection from that same strain. Unfortunately, the "swine flu" or h1n1 strain, just like other previous influenza strains, are always slowly changing their genetic makeup and therefore are able to infect a previously infected-person. This is why an influenza vaccination is recommended every year as the circulating strain almost always differs slightly from year to year. The 2010 influenza vaccine contains strains from the previous "seasonal" influenza viruses (h5n1) as well as the swine flu (h1n1) virus.

Short answer - yes: Swine flu is really only one form of several strains of influenza. Sometimes the doctor or nurse practitioner calls your illness "flu-like"(like swine flu) and treats you for it empirically, even without specifically testing for flu (nose swab test). Later, if you have a repeat of similar symptoms, then this could be labelled a recurrence of "swine flu". My office tests for flu--not swine flu.