Due to the blisters caused by the vaccination that were administered with each needle prick, the scars are clearly apparent. There is a temporary swelling at the injection site, but it goes down to normal after a while. However, a mosquito-bites-like lump develops into a tumor about 6 to 8 weeks after the first infection. once a while, it opens up, starts to flow fluid, and develops into an ulcer; once it heals, a permanent scar forms.