It is stated in the Padma Purāṇa that there are four kinds of effects due to sinful activities, which are listed as follows: (1) the effect which is not yet fructified, (2) the effect which is lying as seed, (3) the effect which is already mature and (4) the effect which is almost mature. It is also stated that all these four effects become immediately vanquished for those who surrender unto the Supreme Personality of Godhead, Viṣṇu, and become engaged in His devotional service in full Kṛṣṇa consciousness.
Those effects described as "almost mature" refer to the distress from which one is suffering at present, and the effects "lying as seed" are in the core of the heart, where there is a certain stock of sinful desires which are like seeds. The Sanskrit word kūṭam means that they are almost ready to produce the seed, or the effect of the seed. "An immature effect" refers to the case where the seedling has not begun. From this statement of Padma Purāṇa it is understood that material contamination is very subtle. Its beginning, its fruition and results, and how one suffers such results in the form of distress, are part of a great chain. When one catches some disease, it is often very difficult to ascertain the cause of the disease, where it originated and how it is maturing. The suffering of a disease, however, does not appear all of a sudden. It actually takes time. And as in the medical field, for precaution's sake, the doctor injects a vaccination to prevent the growing of contamination, the practical injection to stop all the fructifications of the seeds of our sinful activities is simply engagement in Kṛṣṇa consciousness.