无害： I assume that this vaccine will be made the same way as the one we get every flu season. It is a mature technology. Except the slight discomfort you experience from the the injection and your minimum response, there is little risk involved.

有益：The vaccine will be highly effective against the swine flu virus because it will be made specifically using this virus. Again, it is a mature technology and the success is essentially guaranteed if the target flu virus is known.

The basic biology of these flu viruses is the same regardless of its origin. The reason our seasonal flu vaccine is not 100% effective is because the particular virus for a particular season is hard to predict and the seasonal flu vaccine is made based on this imperfect prediction which has been said to be more like an art rather science. In fact, the vaccine we receive each winder is made against multiple viruses. If the prediction is wrong, the vaccine will be less effective.

It will not be the case here as the target is known. So if the swine virus becomes the major strain in the coming season, you are better off receiving it. Even if it doesn't become a problem, the vaccine might still provide some protection against other flu viruses.

From the viewpoint of your working environment, it is probably better to get it. If not, you might get alienated when the flu season comes because people may think that the ones without the vaccine are potential source or carriers of the virus.