Question: Should we go for COVID-19 vaccines, from the Buddhist point of view, after they are certified safe for the masses, also after taking note of individual health considerations?
Answer: Here are various considerations, bearing in mind that the Buddha encourages not harming any sentient beings.  The first two vaccines (used in Singapore) have no animal ingredients in their end products.  But as in all vaccines, unfortunately, there was animal-testing done, which means the processing is not considered vegan.  Yet, the animal-testing was already done, and not taking the vaccines now does not mean animal-testing for future vaccines will stop.  However, we can sign petitions to urge this.  For the present and future well-being of animals, whether the current ready vaccines are taken or not has no apparent effects.  Taking the vaccines can prevent becoming sick and causing others to be sick, with the potential of dying.
As taught by the Pure Land Tradition’s 13th Patriarch Great Master Yìnguāng (净土宗十三祖印光大师) in his ‘Second Reply Letter To Layperson Mù Zōngjìng’《复穆宗净居士书二》, ‘Everyone should, with each person at each person’s home within, along the way when doing things, along the way be mindful [of Amitā(bha) Buddha’s name (i.e. Āmítuófó: 阿弥陀佛)]. When walking, standing, sitting and lying down, being constantly mindful, one definitely will not encounter epidemics (or pandemics)… At all places where there is mindfulness of the Buddha’s name, epidemics (or pandemics) will not enter the area… It is most excellent to eat as pure veg[etari]ans. If they are not able, they also must eat less meat. If yet to eat as veg[etari]ans, they also must be mindful of the Buddha.’ (一路做事一路念【阿弥陀佛】。于行住坐卧中常念，决定可以不遭瘟疫。… 凡念【阿弥陀】佛处，疫不入境。… 顶好吃净素，如其不能，亦须少吃。即未吃素，亦要念。)
Although the Great Master taught that those who practise mindfulness of Buddha and ideally also go (more) veg[etari]an will not be affected by epidemics (and pandemics), the question to ask oneself is —  ‘Am I practising both sincerely enough already, to already be “vaccinated”?’ As can be seen above, all seven points should be considered.
Can Vegans Get A COVID-19 Vaccine?
How To Not Encounter Epidemics And Pandemics?