News Briefs – October 2022 — Is Aluminum in Vaccines Associated with Asthma?

Dr. Paul Offit discusses a recent study that questioned whether aluminum in vaccines is associated with asthma.


Is Aluminum in Vaccines Associated with Asthma?

Paul Offit, MD: Hi, my name is Paul Offit. I'm talking to you today from the Vaccine Education Center at the Children's Hospital of Philadelphia. It's Friday, September 30th, 2022. What I want to talk to you about today is a study that recently has come out questioning whether or not aluminum in vaccines is associated with asthma, or said another way, the more vaccines that you get that contain aluminum that that increases your risk of asthma.

So, is that true? Does that make sense? Should parents be worried about this? So, let's take a step back. First of all, why is aluminum in vaccines? So, aluminum is in vaccines as an adjuvant, and what an adjuvant is, is that it increases, or enhances, your immune response. By putting aluminum salts in vaccines, what that allows vaccine makers to do is to create fewer doses and also have lesser quantities of the active ingredient in there. It makes for better vaccines, and we've been using aluminum adjuvants in vaccines since the 1930s.

So, should we be worried that this aluminum is in vaccines? Well, so let’s take a look at aluminum. Aluminum is a light metal. It's the most abundant light metal on the earth's surface. So, anybody who lives on the planet earth will have been exposed to aluminum in air, and they'll also be exposed to aluminum in anything that they drink and in a number of foods that they eat.

So, if you look, for example, in the blood of people who have gotten vaccines or you look in the bloodstream of people who haven't gotten vaccines, you can't tell whether there's any difference in the aluminum levels because the amount of aluminum that's in vaccines is trivial compared to what you are exposed to and manage every day.

Because we're always exposed to aluminum and because we excrete aluminum in our urine within 24 hours of being exposed to it, we're always having fairly detectable levels of aluminum in our bloodstream. Vaccines don't add to that. Therefore, it would be surprising then that these researchers found that there might be an association then between aluminum adjuvants in vaccines and asthma.

I think the paper was critically flawed for a number of reasons, but the biggest reason is that they didn't do adequate controls to make sure that the group that received aluminum in vaccines was the same as the group that received less vaccines that, therefore, were exposed to less aluminum in vaccines.

So, for example, there are risk factors for asthma. One of the risk factors is a family history. So, you have to make sure that those two groups, the group that received more or less aluminum in vaccines, was the same in terms of the family history for asthma. That wasn't done.

You also have to make sure that, for example, being exposed to pollutants in the air, air pollution, is the same in those two groups. People who live in areas where air pollution is high may have a greater risk of asthma than people who live in areas where air pollution is low. You have to make sure that those two groups are the same then in terms of their exposure to air pollution.

Then, in addition, you have to make sure that the two groups are the same in terms of breastfeeding because breastfeeding tends to protect against asthma. That wasn't done for any of those three things. And, therefore, because it wasn't a well-controlled study, I think we learned nothing about the association between aluminum in vaccines and the development of asthma.

So, I want to reassure parents that I think that this is a paper, frankly, that should have never been published because it adds nothing to our understanding of vaccines.

Thank you.

Related Centers and Programs: Vaccine Education Center