user: Question: Name the least age for the 1st dose for 3 doses of 2-3 drops
Columns: ['Vaccine', 'Minimum Age at 1st Dose', 'Number of Doses', 'Dose', 'Minimum Interval Between Doses', 'Route']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Bacillus Calmette-Guérin', 'Birth or anytime after birth', '1 dose', '0.05 mL', 'none', 'Intradermal']
SQL:

assistant: SELECT MIN("Minimum Age at 1st Dose") FROM "Table" WHERE "Number of Doses" = '3 doses' AND "Dose" = '2-3 drops';