• Students from the University of Arizona College of Medicine will be holding free Tot Shot clinics this summer at the Community Food Bank, 3003 S. Country Club Road. The clinics are scheduled for 9 a.m. to noon on July 28 and Aug. 18.

• The Pima County Health Department holds regular immunization clinics throughout the year. The department also holds back-to-school clinics in July and August. For a complete schedule of clinics, go to www.pimahealth.org/ The Health Department's administration fee is $15 for a single shot, $25 for two to five vaccines, and $35 for more than five vaccines. Fees can be waived for an inability to pay. Adults are charged the price of the vaccine plus an administration fee.

• Regular county clinics plus hours. The clinics are walk-in except where appointments are specified: • Ajo Office, by appointment, 1-520-387-7206. • Catalina Community Clinic, 3535 E. Hawser, by appointment, 825-9299 or 243-2850. • East Office, 6920 E. Broadway, 1-4 p.m. Mondays and 9 a.m.-noon on the third Saturday of month, 298-3888. • Green Valley Office, 601 N. La Cañada Drive, 1-4 p.m. Wednesdays by appointment, 648-1626. • North Office, 3550 N. First Ave., 1-7 p.m. Thursdays, 243-2850. • South Office, 175 W. Irvington Road, 1-4 p.m. Tuesdays and 1-6 p.m. on the fourth Tuesday of the month, 889-9543.

What about adults?

Before 2005, the only booster available contained protection against tetanus and diphtheria (called TD), and was recommended for teens and adults every 10 years. Today there is a booster for preteens, teens and adults that contains protection against tetanus, diphtheria and pertussis (Tdap). Adults should get vaccinated with Tdap at least two weeks before coming into close contact with an infant. This is especially important for families and caregivers of new infants.

The current recommendation is one DTaP, then back to the 10-year TD schedule. It remains to be seen whether there is a need to reboost the pertussis immunity with DTaP 10 years after the first dose.