Bird flu continues to make news as its found that a vaccine does not work as well as it was hoped. It turns out that only 45 percent of the people who were given the series of two vaccination shots actually produced antibodies. This was a study done with 452 adults.

Normally a vaccine works by introducing a small amount of the disease causing virus to people in the form of an injection. This is usually dead or inactivated virus that provides just enough of a signature to cause the body to produce antibodies so that if there is a real threat the body knows what do and can fight the infection more readily.

In this case, over half of the people in the study did not produce the antibodies, so it’s likely the vaccine’s signature was not quite strong enough to trigger the body’s defences.

It’s a tricky thing to make something like this work. Since the virus can be deadly, you don’t want to risk overexposure and having the test subjects actually catch the disease. While the overall fatality rate is pretty low for the disease - 167 people worldwide have died from the disease in the last three years - the potential for a widespread outbreak is what makes people nervous.

Since it has proven to be quite virulent (spreads very easily) among poultry, the assumption is that if it makes the jump to humans and can be spread easily through human to human contact then there could be quite an epidemic to deal with.