Here's a summary of the actual research on aluminium in vaccines. From real, peer reviewed science, not the bollocks you read on some blog by a homeopathy practitioner from Alabama.
Taken from vk.ovg.ox.ac.uk/vaccine-ingredients
Aluminium, an adjuvant
Many vaccines contain aluminium salts such as aluminium hydroxide, aluminium phosphate or potassium aluminium sulphate. They act as adjuvants, strengthening and lengthening the immune response to the vaccine. Aluminium salts appear to slow down the release of the active ingredient from the vaccine once it is injected, and stimulate the immune system to respond to the vaccine. They also absorb protein well, and stop the proteins in the vaccine sticking to the walls of a container during storage.
Aluminium is the most common metal in the earth’s crust and we are exposed to it all the time. It reacts with other elements to form aluminium salts, and small amounts of these are found naturally in almost all foods and drinking water, as well as in breast milk and in formula milk for babies. Aluminium salts are used as food additives (for example in bread and cakes) and in drugs such as antacids, and aluminium is widely used in food packaging.
Aluminium is not used by the body. Any aluminium absorbed from food or other sources is gradually eliminated through the kidneys. Babies are born with aluminium already present in their bodies, probably from the mother’s blood. Over time, small amounts of the aluminium from food, drink and other sources do accumulate in the body, but this is not believed to pose a significant risk to health (see for example this UK research from 2004 ). The view of most experts is that there is currently no convincing evidence that exposure to everyday levels of aluminium in any form increases the risks of Alzheimer’s disease, genetic damage or cancer.
The amount of aluminium present in vaccines is small - less than 2 milligrams of the salts, and less than a milligram of actual aluminium. In the UK, the highest dose of aluminium that babies receive in one go from vaccines is just under 1.5 milligrams (from the 6-in-1, PCV and MenB vaccines at 8 weeks and 16 weeks). A study from 2011 modelled the impact of aluminium from diet and vaccines in infants, and concluded that the total amount of aluminium absorbed from both sources was likely to be less than the weekly safe intake level. A study from 2002 drew similar conclusions. A study published in March 2018 took samples of blood and hair from 85 babies and measured their levels of aluminium. These levels varied considerably, but researchers did not find any correlation between aluminium levels in blood or hair and the estimated amount of aluminium that the babies had received from vaccines.
Vaccines that contain aluminium are associated with more redness and hardness at the injection site than other vaccines. Rarely, aluminium adjuvants may cause small itchy lumps (granulomas) to form at the injection site. A 2014 Swedish study found that this happened in a small number of children (fewer than 1 in 100) after vaccination with the 5-in-1 vaccine (Infanrix) and pneumococcal vaccine (Prevenar). Granulomas are not dangerous but can be irritating and last for months or even years. The study found that children with granulomas often developed an aluminium contact allergy. However, most children recovered from their symptoms.