From a child’s first days, immunizations are a major — and complex — part of their health care. As such, questions including “Why does my child need all of these vaccines?” and “Are these safe?” to “Am I doing enough to protect my child?” and “Am I timing all of this right?” can cause worry, stress or confusion for many parents.

Vaccines are indeed very important, and a point of emphasis in most medical settings. However, they shouldn’t be a source of strife for families. To help address some of the most common vaccine questions, Mark Sawyer, M.D., attending physician in the Division of Infectious Diseases at Rady Children’s Hospital-San Diego and professor for the Department of Pediatrics at University of California San Diego School of Medicine, provides some straightforward information in a new Kite Insights Q&A.

Let’s start with the basics: Why are immunizations so important, both for individual protection and protecting whole populations?

An ounce of prevention is worth a pound of cure. Immunizations are our most effective tool to prevent illness and death from infectious diseases. Even diseases that we can treat with antibiotics or antiviral medication still cause lots of suffering by the time we get them under control. It is much better to prevent them altogether. Compared to a time when we didn’t have vaccines, we have reduced the rates of diseases such as polio, measles, mumps and tetanus by more that 98 percent. Other diseases, for which vaccines aren’t quite as effective, have still been reduced by more than 90 percent. In fact, vaccines have saved hundreds of millions of lives around the world in the last 20 years.

Vaccines work in two ways: they protect the person who gets them, but they also can indirectly protect people who are not immunized. If enough people get vaccinated, then the diseases stop circulating, and even unvaccinated people end up being protected because they simply aren’t exposed to the disease. However, this only works if a very high percentage of the community gets vaccinated. So, we have to keep our guard up.

What are alternative immunization schedules? Are these advisable? If so, how can parents find the right schedule for their child?

There really aren’t any alternative schedules. People have made up different ways to give vaccines, but they have never been tested, so we don’t know if they work. Since the recommended schedule from the Centers for Disease Control and Prevention (CDC) and the American Academy of Pediatrics (AAP) is designed to give vaccines as soon as they can be given, all of the so-called alternative schedules end up delaying vaccines. Parents get convinced that this is somehow safer, but the opposite is actually the case. When you delay a vaccine, you leave your child at risk for the disease the vaccine is designed to prevent. You are taking your chances that they won’t get exposed before they eventually get vaccinated. It is an approach that doesn’t really make sense — it would be like waiting to put your infant into a car seat until they are a year old. Almost all parents choose to get their children immunized on time based on the recommended schedule.

Most schools and child care facilities require children to have certain vaccines before enrolling in essentially all cases. In California, for example, personal belief exemptions haven’t been accepted since Jan. 2016; however, medical exemptions still are. In what situations might a child truly need a medical exemption from a vaccine? Would this apply to particular vaccines, or all?

There are very few reasons a child would need a medical exemption, and most medical exemptions apply to only one vaccine. The main reason children might need a medical exemption is if they have had an allergic or other serious reaction to a previous dose of a vaccine. In that case, we don’t repeat the vaccine. The only other reason medical exemptions are given is for children whose immune systems don’t work well — for example, children with cancer. These children can’t respond to certain vaccines, or may have more side effects. It’s these children we need to protect by making sure everyone around them is vaccinated.

There have been a number of studies, including one very recent one, debunking the idea that immunizations lead to conditions including autism spectrum disorder. In spite of findings, hesitancy to vaccinate children has gained traction. From your professional perspective, why do you think that is? How can parents learn more and mitigate their concerns?

The autism story is a sad one. Even though it has been proven beyond a shadow of doubt that vaccines don’t cause autism, you can still read on the internet that they do. It is very hard to judge the accuracy of things on the internet. My advice is for parents to ask their child’s pediatrician to guide them to accurate sources of information so that they can read for themselves why we know vaccines are safe.

Why are some vaccines mandatory and some recommended?

The primary reason some vaccines are not required for day care or school is that they are for conditions not commonly transmitted while at these facilities, such as human papillomavirus. From my point of view as an infectious disease specialist, all the vaccines are important.

There is a lot of content out there about immunizations that is simply inaccurate. What resources can parents trust to get factual, up-to-date information and make informed decisions about their children’s health?

Among the best sources of information about vaccines and their safety are the CDC, the AAP and the Immunization Action Coalition. All three have excellent information for parents. If parents want more information, they should talk to their child’s doctors, and also ask them about other reliable sources of accurate information.