COVID-19 vaccines for infants, toddlers and preschoolers are ready to go into their tiny arms as soon as today in Santa Clara County.

The county on Monday received shipments of both the Pfizer and Moderna versions of the vaccines for children 6 months through 4 years old, and in the afternoon began offering up appointments online at www.sccfreevax.org to administer the shots starting Tuesday.

“We know how long families have been waiting for this moment,” Santa Clara County Health Officer Dr. Sara Cody said Friday in anticipation of the vaccines’ authorization. “This will be our final step in being able to vaccinate everyone in our community, of every age.”

Contra Costa County health officials said they will start giving the vaccines at their clinics on Wednesday, and have begun posting updates online on a new Vaccination for Kids web page.

Kaiser Permanente expects to begin receiving vaccine shipments over the next week, and said Monday that members should check kp.org for availability of appointments in their area.

Sutter Health said Monday that appointments can be scheduled by phone at 1-844-987-6115 from 7:00 a.m. to 6:00 p.m. Monday through Friday, and will be available soon through its My Health Online patient portal. Sutter said to check its vaccine resources page online for updates.

National pharmacies are also offering the vaccines for kids under age 5, though many are only able to give them to kids who are at least 3 years old due to immunization training requirements and laws in many states.

Walgreens will offer vaccines to children 3 years and up. Appointments will be available beginning Saturday, June 25, and can be scheduled online at Walgreens.com/ScheduleVaccine, through the Walgreens app, or by calling 1-800-Walgreens.

CVS said it will begin administering the Pfizer-BioNTech COVID-19 vaccine for eligible children as young as 18 months through 4 years old at its 1,100 MinuteClinic locations in 35 states starting on Tuesday. Appointments will be made available at MinuteClinic.com on a rolling basis as locations receive supply.

CVS offers a clinic locator online as well.

Alameda and San Mateo counties are urging families to seek vaccination through pediatric offices or pharmacies.

“The county’s vaccination strategy for 6 months to 4-year-old children is focused on increasing the number of pediatric practices able to vaccinate their patients,” Alameda County said in a statement, adding that those offices are receiving vaccines this week.

“Believing that the best place for young children to receive the vaccines is in the care of a pediatric provider, San Mateo County Health will not offer large-scale vaccine clinics to children under 5 or at its community clinics,” the county said in a statement. San Mateo County will instead provide small-scale clinics at Early Head Start sites, and staffing and administrative support to interested pediatric providers that serve publicly insured families. The county will continue offering vaccination to children age 5 and older.

The Food and Drug Administration authorized the vaccines for emergency use in children under age 5 last week and the Centers for Disease Control and Prevention on Saturday recommended that children receive them.

The Moderna vaccine is given in two shots a month apart. The Pfizer vaccine is given in three shots, with a second three weeks after the first and a third eight weeks after the second.