The reason why dogs have Lyme disease vaccines but not humans is because Lyme disease vaccines are often safer and even more effective in dogs and there's also not as much public concern about them for dogs.
A human Lyme vaccine for humans was once available which was called LYMERix although it was withdrawn as a result of safety concerns and a strong anti vaccination movement.
Although current research is still now exploring some new Lyme vaccines for humans, although as of now they are still in their early stages of development.
Vaccines for dogs including the Lyme vaccine for dogs is often well tolerated in dogs, with less reported side effects when compared to the human LYMERix vaccine.
Also dog vaccines for Lyme disease have shown to have good efficacy in prevention of Lyme disease.
And veterinary medicine has also generally embraced Lyme vaccines for dogs, which makes Lyme vaccines more readily available and widely used for dogs.
Vaccines for dogs like Lyme disease vaccines are mostly focused on prevention of Lyme disease and to minimize the risk of Lyme disease in dogs.
For humans the human LYMERix vaccine was also associated with some concerns about some potential side effects that were later found to be unfounded, although it also led to the withdrawal from the market.
The human Lyme disease vaccine also had some issues with it's effectiveness and most particularly in prevention of Lyme disease in people and the need for multiple doses of the Lyme vaccine and yearly boosters also lead to low sales and ultimately the withdrawal of the Lyme disease human vaccine.