DTaP vaccine

DTaP vaccines are combination vaccines vaccines against diptheria, tetanus, and pertussis. These vaccines contain diptheria, tetanus, and pertussis toxoids (inactivated toxins) adsorbed onto aluminum-based adjuvants, as well as other pertussis antigens.

Effectiveness
According to the CDC, the administration of diphtheria and tetanus vaccines following the recommended schedule makes 95-97% of people immune to diphtheria and nearly 100% of people immune to tetanus. The CDC says that after completing the recommended 5 dose series of DTaP, 98% of children are completely immune to pertussis, and 71% are still completely immune 5 years later,  while a Cochrane review found that the pertussis vaccines used in the US are 84-85% effective at preventing typical pertussis, and 71-78% effective at preventing mild pertussis. Some vaccinated people are not completely immune to pertussis but have milder or asymptomatic infections.

Usage
The CDC recommends that children receive 5 doses of DTaP, with 1 dose at each of the following ages: 2 months, 4 months, 6 months, 15-18 months, and 4-6 years. Additional vaccines against diptheria, tetanus, and pertussis (Tdap and Td) are recommended for older children and adults, but DTaP is only used for younger children.

Safety
The following rates of serious adverse effects have been documented or estimated to occur after DTaP vaccines

In a 2011 vaccine safety review, the Institute of medicine found no reliable studies on whether DTaP vaccines cause autism, and said that the mechanistic evidence for such a causal relationship is "lacking", ultimately concluding that there is insufficient evidence to accept or reject a causal relationship between DTaP and autism.