The term vaccination does not occur in the Bible. For this reason, it is not so easy to draw conclusions about this subject from the Bible. As with so many things that cannot be deduced from the letter of the Bible, here too it is necessary to try to act in spirit of God's Word.
Clearly, we should not deal carelessly with our body, or with our health. Our body is represented as being the temple of the Holy Ghost (1 Corinthians 6: 12-20). Moreover, we are God's creatures and it would show little respect to the Creator if we deal carelessly with His creation (including our body). Up to this point there is little confusion among Christians.
There is however a difference of insight concerning the relationship between human responsibility (taking measures) and God's providence. God's providence does not take away our responsibility. After all, our human responsibility would then be cancelled for the benefit of God's providence. It is not so; on the contrary: pray and work.
When Joseph hears from God in his dream (Genesis 41) that seven years of plenty would come, followed by seven years of famine, he decides that the surplus harvest from the first period should be used to prepare a store to prevent a famine in the second period. Today we would say: he takes precautionary measures. Another example can be found in Nehemiah's mission (Nehemiah 2:7 and further). He is given permission from the Persian king to help his people in rebuilding Jerusalem. The journey there was not without danger, and Nehemiah requests and is granted letters of recommendation to guarantee a safe passage. He is also accompanied by an army for protection. So he takes safety precautions because he felt the responsibility for his employees and the success of his assignment.
The measures that Nehemiah took alluded to above form an apparent conflict with the steps taken by Ezra, who a number of years earlier undertook a similar mission. Ezra took no safety precautions, but trusted on the evident protection of the Lord (Ezra 7 and 8, in particular 8:22 ).
Prudence should be observed when applying the passage recorded in Matthew 6: 25 and further too literally: ‘Therefore I say unto you, Take no thought for your life, what ye shall eat, or what ye shall drink; nor yet for your body, what ye shall put on. Is not the life more than meat, and the body than raiment?...’ Various reformed ethicists (among others Prof Dr W.H. Velema and Prof Dr J. Douma) see in this primarily a warning against on the one hand carelessness and on the other hand exaggerated attention for the inside and outside of the body. It is not the intention that we should not care at all about the necessities of daily life. It is about us not doing that in a stressful way, as though everything depended on it, but trusting in the Lord.
It is often said that medicines that make people ill, should not be used. These kinds of medicines are no longer used nowadays. So that argument no longer applies as a motive for rejecting vaccination. The question then is whether we may take precautionary measures against a possible illness, in such a way that we do not come into conflict with a faith in the sovereign God (Heidelberg Catechism Lord's Day 10).
Apparently, we here have two matters that are in conflict with each other: on the one extreme degeneration into human activism and attempts to cover one's self completely (risk avoidance), on the other extreme complete passiveness whereby every human activity is explained as being a lack of faith. Yet the history of both Ezra and Nehemiah show that two God-fearing men with the same mission had two different views with respect to responsibility and providence, while history shows that the work of both of them was blessed by the Lord. So one should be careful in judging one's neighbour too soon when his conscience takes a different view in the same situation.
A situation involving a threat of infection can be a reason for vaccinating after all. Here one goes from a general prevention situation to a situation in which there is a real chance of getting an infection from the condition or infection in question. Such a situation can occur for instance if someone is not vaccinated against polio, but does so as soon as the illness has broken out in the area. This measure can be seen in the light of the Heidelberg Catechism Lord's Day 40, in which among other things the sixth commandment (Thou shalt not kill) is explained such that I am not to harm or recklessly endanger myself because that would be tempting God. Here too the words of the apostle Paul are true: Let every man be fully persuaded in his own mind (Romans 14:5b). The human conscience is far from perfect, and making a claim on one's conscience does not release us from the obligation to take up a clearly substantiated standpoint. Doubts and fears (also of faith) are poor advisers, the conscience may also be influenced by false arguments.
God's providence and human precautionary measures
The Bible does not forbid us to take precautionary measures. On the contrary, if one built a home in ancient Israel, a fence had to be placed on the flat roof as a precautionary measure (Deut. 22:8). Apparently one was not supposed to hide behind God's providence.
However, at first sight the field of health and illness is quite different from that of the construction industry. Vaccination would seem to be something quite a lot different from a fence on the roof. Yet they are both precautionary measures. The old argument that vaccinating people makes people ill, no longer holds.
The problem here is to be consistent. Why do we reject vaccination with the argument that God sends illness and why do we not reject the sprinkling plant, for after all God also sends the drought? We pray for preserving mercies on the way, but we also have to put on our seat belts. Here we touch on a difficult point, because we are entering the field of human conscience. And that conscience is influenced by different factors. By our upbringing, by culture and in the case of Christians, by how we interpret the Bible.
The apostle Paul had to deal with people who for conscience's sake would not eat flesh that had been offered to idols. He pointed out that it was permitted to eat this, but that it is a good thing to take account of each other's sensitivities (2 Corinthians 8). It is certainly not for us to pass judgement.