Often, they say things that clearly highlight their ignorance and lack of quality information. Whether it's pointing out long lists of preservatives or components as proof of their harm, saying things like - Hep B only infects drug users and prostitutes, babies can't even make antibodies so this doesn't even work, illnesses like chicken pox carry lower risk than the vaccine, pharmaceutical companies face no liability, and on and on. For once, I would just like to enjoy having a sensible discussion with these people.

Here, let me show you how it's done.

Hepatitis B is rarely contracted in the infant and pediatric age range.  Since it's a communicable disease, we can actually track the incidence pre and post-vaccine.  Prior to widespread usage of the vaccine in the early 90s, the rate of acute hepatitis B infection in kids age 1-9 was about 8 in 1 million.  

By 2000, we saw that rate drop to about 1 in 1 million.  Certainly it's possible and likely that our own hygeine practices, identification methods, and treatement of these conditions contributed to reducing the rate of Hep B.  But let's pretend that the drop was 100% attributable to the vaccine.  In that case, 7 in 1 million benefited from the vaccine.  Of kids in this age range who contract Hep B, 25-50% will develop chronic Hep B, which is fairly severe and can lead to chronic liver failure and death.  Let's just use the high number (50%) for our data.  This would mean that there is roughly a 3.5 in 1 million chance of preventing Hep B infection in any given child.  

You could certainly argue that your own child will have far less exposure to Hep B than the kids who were infected and included in this data.  You could say that your child is not being born to a mother who is a carrier, is not receiving any blood products, and isn't traveling to any high risk areas or being exposed to people with chronic infection.  You could also point out that the incidence of Hepatitis B is so much lower these days than it was in 1990 and therefore current incidence would be much lower than 8 in 1 million.  Taking those factors into consideration, you could argue that your child's chance of benefiting from the vaccine is less than 1 in millions or even lower.  

In summary, you could say that you are willing to take the 1 in 5 million (very very rough estimation) or less chance of your child developing chronic hepatitis B in order to avoid any chance of vaccine adverse reaction.

Now, it would also probably be smart to acknowledge that the more people who follow this practice, the more prevalent Hep B will become so some of these numbers could change.

This would be an argument that is at least more interesting than all the crap that people push that is filled with mommy-blogger data. And I am sure that my data and information is full of flaws and inaccuracies, but at least it's a starting point for a more interesting discussion. It's certainly better than saying "My daughter isn't a drug user or prostitute so she is safe".