Why can't babies and young kids get shots at pharmacies? The answer is complicated.

Finding time to take children to the doctor's office to get a flu or COVID-19 vaccine can be tough, especially if it's not part of a routine visit. If you don't have access to a pediatrician, don't have a regular doctor or see a pediatrician whose vaccine appointments book up early, this can be even more difficult.

Given how tricky it can be to get people of any age to get a vaccine, many pharmacies conveniently offer shots in their stores — but these usually exclude young children. CVS, for example, says online that COVID-19 vaccines are limited in its stores to patients ages 5 or older. For flu shots, most CVS pharmacy locations can vaccinate kids ages 3 and up, but the chain notes online that "some states have different minimum ages." To make things even more confusing, the brand's MinuteClinic providers can usually vaccinate kids as young as 18 months.

At Walgreens, children need to be at least 3 to get their flu and COVID-19 shots. And other pharmacies have their own policies.

Why can't young kids get shots at pharmacies, and what's with the differing age requirements? Pharmacists and an infectious disease doctor explain.

Why it depends on where you live

State law has traditionally dictated the minimum ages for kids to get vaccinated at pharmacies, Dr. William Schaffner, an infectious disease specialist and professor at the Vanderbilt University School of Medicine, tells Yahoo Life. "These minimum ages depend upon the state, and each state decides whom pharmacists can immunize," he says. "Some states have not permitted pharmacists to vaccinate young children."

But that's how it's historically been, Christina Inteso, a clinical pharmacist at Corewell Health, tells Yahoo Life. "About half of the states allowed pharmacists to vaccinate those over the age of 7 and the other half allowed pharmacists to start vaccinating at birth," she says.

That all changed with the COVID-19 pandemic. During its height, the Public Readiness and Emergency Preparation (PREP) Act was passed, granting pharmacies in all 50 states the ability to give vaccines to kids as young as 3 without liability concerns. But some states have expanded on that — 27 states allow pharmacists to vaccinate children under the age of 3, according to the American Pharmacists Association and the National Alliance of State Pharmacy Associations.

The PREP Act "is still in effect until December 2024, but could be extended or renewed," Inteso says. "States also have the ability to update their laws based on this current policy and many have done so," she adds.

Things get a little complicated with the law, though. In April, the Department of Health and Human Services (HHS) announced that once there is no COVID emergency declaration in effect, PREP Act coverage will no longer extend to routine childhood vaccinations by pharmacists, pharmacy interns and pharmacy technicians. The COVID emergency declaration has ended and, as a result, pharmacies don't need to offer these vaccines anymore. However, states and pharmacies may choose to continue to offer this service. If you're unsure of what your local pharmacy offers, call it for details.

Why have a minimum age in the first place? "Children have a little bit different anatomy than adults — the 'target' is a bit harder to hit," Jamie Alan, an associate professor of pharmacology and toxicology at Michigan State University, tells Yahoo Life. "[Those who administer vaccines] also should be trained in CPR, and CPR training is different for small children."

But the policies also often have more to do with factors outside of vaccines, Inteso says. "In the past, various medical groups such as the American Academy of Pediatrics (AAP) and the American Medical Association (AMA) have strongly opposed children being vaccinated at the pharmacy," she says. "There is concern that children may skip their well-child checkups with a pediatrician if they are getting vaccinated at the pharmacy."

Another barrier is that the pharmacy would need to stock child-specific vaccines, she says, noting that "most differ from adult vaccines." With that, "extra care would need to be taken to make sure the right vaccine went to the right age group," Inteso says.

What's with the differing age requirements between pharmacies?

That's often due to company policy, Schaffner says. "The question is: Are the pharmacists prepared for this and are they trained to vaccinate young children?" he says. Kids can be a little trickier to vaccinate than adults — they tend to squirm more and may scream or cry when they're vaccinated, Alan points out. As a result, some companies just may decide they don't want to deal with it.

Pediatricians often have a second nurse or medical assistant who can help distract or soothe a child while the vaccine is given, Inteso says, and a busy pharmacy may not have an extra person to help with that.

Is it safe to have children vaccinated at a pharmacy?

For what it's worth, the PREP Act laid down stringent and very specific requirements for pharmacists and pharmacy interns to meet in order to offer pharmacy-based vaccination programs. Anyone who gives vaccines at a pharmacy must meet the following specifications:

• They must complete a minimum 20-hour practical training program from the Accreditation Council for Pharmacy Education (ACPE). That includes hands-on injection techniques, evaluation of who can and can't get the vaccines and the training in the ability to recognize reactions to vaccines and respond appropriately.

• They can give vaccines that are approved only by the Food and Drug Administration and that are on the immunization schedules of the Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices.

• They must be currently certified in CPR.

• They must complete a minimum of two hours of ACPE-approved continuing pharmacy education related to vaccinations.

• They need to follow documentation and record-keeping requirements. That includes entering vaccination records into state and local vaccination registries.

• They need to be able to educate parents on the importance of well-child visits with a pediatrician.

Alan says that it's safe to have children vaccinated at your local pharmacy, provided they meet the mandated age requirements. "But if you have a child you would consider a 'difficult stick,' I would call ahead to make sure the vaccine administrator is comfortable and good with children," she says. If not, Alan recommends visiting your pediatrician (if you have one) to make the process easier on your child.