Do Vegans Who Get a COVID-19 Vaccine Abandon Their Moral Principles? Yes — and No.
Although the vaccines for COVID-19 that are presently available are being represented as having no animal ingredients, the blood of many thousands of horseshoe crabs is being used to make sure that the vaccines are free of contamination. Although the crab blood is technically not an ingredient of the vaccine, it might as well be. Horseshoe crabs are not really crabs; they are more closely related to spiders and other arachnids than they are to crabs or lobsters. But horseshoe crabs have a complex nervous system and it is very likely that they are sentient, or subjectively aware and able to experience pain. The crabs are captured, placed in racks, and have the tissue around their hearts pierced. Up to 30% of their blood (which is blue) is drained. The process is certainly distressing to the crabs.
Although they are returned to the ocean, between 10% and 30% of the crabs die in the bleeding process and after they are returned. Many are re-caught and bled again. Although there is a non-animal alternative to using crab’s blood, that alternative has not been accepted and will not be employed with respect to the COVID-19 vaccines.
So Putting aside any issues of animal testing of the finished vaccine, this raises the question about whether it is morally acceptable for vegans to get the vaccine. I have been a vegan since 1982. I take my veganism very seriously. I believe that we cannot justify using sentient nonhumans exclusively as resources for humans for any reason (food, clothing, entertainment, research, and so forth), and that we have an obligation to abolish all animal use. Therefore, I do not think that we can morally justify getting the vaccine.
But I don’t think that that ends consideration of the matter.
I want to make a distinction between actions that are morally justifiable and those that are morally excusable. The former are acts that are morally good acts, or are at least not morally objectionable. The latter are acts that are morally objectionable but where circumstances mitigate the culpability of engaging in the act.