Contrary to what was expected earlier, the vaccine may not be multi-dose. Result of a pilot study of Novartis, H1N1 candidate vaccine revealed a strong immune response after just one shot. Novartis said that more than 30 governments have requested vaccine supplies including the US. Scientist from the University of Leicester, who tested the vaccine on 100 health volunteers aged between 18 and 50, found that more than 80% of the volunteers showed a strong, potentially protective immune response after one dose. According to them, the trial findings showed that it is possible to induce protective antibody against H1N1 infection within two weeks of administration of a single low-dose adjuvanted vaccine.

There have been many concerns expressed over the potential safety of the H1N1 vaccine which has been fast-tracked and will not go through the same testing process most vaccines do. It will be tested only for one to three weeks on a few hundred children and adults before being released. Further, most doses of this experimental vaccine will contain Thimerosal, the mercury-based preservative that has been associated with brain and immune system dysfunction, including autism.

Experts are of the opinion that a group of people comprising of:

• pregnant women,
• household contacts and caregivers for children younger than 6 months of age,
• health care and emergency medical service personnel,
• all children and young adults from 6 months through 24 years of age and persons aged 25 through 64 years,

Suffering from  who have health conditions associated with higher risk of medical complications from influenza.

Although five companies are making H1N1 swine flu shots, including Sanofi Pasteur, Novartis, GSK, Medimmune and CSL, doctors won’t be able to directly order swine flu vaccine from them.

Swine Influenza (also known as swine flu, hog flu and pig flu) is an infection by any one of several types of swine influenza virus. Although uncomplicated influenza-like illness has been reported in many cases, mild respiratory illness without fever and occasional severe disease also has been reported.