Answer from Danavir Goswami
Generally we learn from the scriptures that any contact with non-devotees is contaminating since their habits, mind, and consciousness are unclean. It is recommended in the description of Ambarisa Maharaja that he engaged his sense of touch in touching the bodies of devotees. That means he regulated his intimate friendly dealings. For preaching purposes we sometimes touch the non-devotees but we should be strong enough not to be affected by such contact.
A baby is not really preaching yet so I would recommend as much association with devotees as possible. If some contact with materialistic persons is absolutely required then the best remedy is to chant the maha mantra and other protective mantras for the baby’s protection as did Mother Yasoda for baby Krsna.
After rising early in the morning, mother Yaçodä first of all offered her breast milk to Kåñëa, and then she began to chant various mantras for His protection. Then she would decorate His forehead very nicely and bind His arms with protective talismans.
“My dear Kåñëa, may the Lord who is known as Aja protect Your legs; may Lord Maëimän protect Your knees; may Lord Yajïa protect Your thighs; may Lord Acyuta protect Your upper waist; may Lord Hayagréva protect Your abdomen; may Lord Keçava protect Your heart; may Lord Éça protect Your chest; may Lord Sürya protect Your neck; may Lord Viñëu protect Your arms; may Lord Urukrama protect Your face; may Lord Éçvara protect Your head; may Lord Cakradhara protect Your front; may Lord Gadädhara protect Your back; may Lord Madhusüdana, who carries a bow in His hand, protect Your right side; may Lord Ajana protect Your left side; may Lord Urugäya with His conchshell protect You on all sides; may the Personality of Godhead Upendra protect You from above; may Lord Tärkñya protect You on the ground; may Lord Haladhara protect You from all sides; may the Personality of Godhead known as Håñékeça protect all Your senses; may Lord Näräyaëa protect Your life airs; may the Lord of Çvetadvépa, Näräyaëa, protect the core of Your heart; may Lord Yogeçvara protect Your mind; may Lord Påçnigarbha protect Your intelligence; and may the Supreme Personality of Godhead protect Your soul. While You are playing, may Lord Govinda protect You from all sides, and when You are sleeping, may Lord Mädhava protect You from all danger; when You are walking, may the Lord of Vaikuëöha protect You from falling down; when You are sitting, may Lord Näräyaëa give You all protection; and while You are eating, may the Lord of all sacrifices give You all protection.”
