Dr Michael Shaw and his team at the CDC are making rapid progress in understanding the H7N9 influenza virus that is causing lethal cases of flu in China. There is great concern about this virus, and its potential to cause a serious pandemic. Currently the virus is not transmitting readily human-to-human, with most cases being bird-to-human. Unfortunately, the virus does not seem to greatly sicken birds, making it harder to detect and easier to spread. You can find some cool graphics and images of influenza at the CDC
The good news is that a new vaccine production method was approved by the FDA in 2012. In this method, the parts of the influenza virus that raise an immune response in our bodies (called hemagglutinin) are cloned into a different type of virus and grown in cell culture. Large quantities of the vaccine can be produced rapidly. This is much better than the old method of growing virus in eggs because production of vaccine is not dependent on the egg supply, you don’t have to adapt the virus to grow in eggs, and it is not depended upon the growth of the wild H7N9 virus in the laboratory. The CDC is already preparing a vaccine just in case the virus begins to spread human-to-human.
If you would like to learn more about influenza, Chapter 18 has a section on the virus and how it replicates.