Babies typically come into contact with seven different people every day, according to the first study of its kind.
Interactions with mothers, fathers, siblings and youngsters at playgroups were among the daily contacts recorded for babies aged 12 months and under.
The research, from Public Health England (PHE), was carried out to provide information to help protect babies against infections, especially those who are too young to be vaccinated.
Overall, 115 mothers filled out a 24-hour diary on contact for their babies and the results were split into babies aged 10 weeks and under and those who were aged 10 weeks to 12 months
Of those aged 10 weeks and under, 37 per cent of contacts were with non-household members and were less than 15 minutes duration.