The earliest vaccines were made from liquid from the pocks of cattle.
最早的疫苗是用牛的痘浆制成的。
vaccine lymph:痘浆
vaccine inoculation ==> 菌苗注射,菌苗注射,疫苗接种 | vaccine lymph ==> 痘浆 | vaccine poisoning ==> 疫苗中毒