Sheikh `Abd al-Wahhâb al-Turayrî, former professor at al-Imâm University in Riyadh
Vaccinations, anesthetic injections, and other non-nutritive injections do not break your fast because they do not constitute eating or drinking. Such injections do not resemble eating or drinking in any way.
Nutritional injections, on the other hand, do break your fast because their effects resemble those of eating or drinking.
Though it is alright to take non-nutritive vaccinations while fasting in the month of Ramadan, it would be better to take them at night, if possible.
And Allah knows best.
Source: Islam Today