Why the Delay in H1N1 Shots?

By Julie Stachowiak, PhD
Multiple Sclerosis Guide; Guest blogger

Sure, you might be angry about the delay in vaccines, or the long lines, or what people are calling "empty promises" about the millions of H1N1 (swine flu) vaccine doses that have not yet materialized in expected numbers.

However, if you really want to place the blame on anyone, point your finger at the H1N1 virus itself. It seems like the little guys just do not want to multiply as quickly as seasonal flu in eggs, which is where the virus that is used for vaccine is grown.

To make virus for vaccine, live virus is injected into the tops of eggs, which are then cared for lovingly and kept at just the right temperature for a period of time. It is then harvested and rigorously tested for purity and safety (the entire process from injection of virus into eggs to a vaccine ready to put into a person takes 3 months). To the surprise (and dismay) of companies making the vaccine, they found that the eggs yielded much less virus than was expected, causing a big bottleneck in the vaccine pipeline. Early on, I heard that each egg was providing enough virus for only 1.5 vaccines, whereas the process usually yields enough virus for 4 vaccines per egg.

Company spokespeople and government officials are now assuring people that the problem has been fixed somehow and the virus (and vaccine) production are back on track, so that we should be seeing the millions of doses that we have been expecting very soon.