How Do Vaccines Work?

Vaccines are vital for your wellbeing and the health of our communities. They’re also safe. In fact, Stephen Rinderknecht, DO, UnityPoint Health says they’re safer than most of the foods we eat! Dr. Rinderknecht explains how vaccines work and three reasons to stick with your doctor’s recommended vaccine schedule.

How Do Vaccines Work?

“When you get a vaccine, the body is exposed to a harmless material that mimics a disease-causing microbe,” Dr. Rinderknecht says. “Our body recognizes it as a danger and produces antibodies and white blood cells to protect us in the future, if we ever get exposed to the real thing.”

Only a few vaccines include a live virus. Those include the MMR (measles-mumps-rubella), varicella, rotavirus and the nasal flu vaccine.

“The virus in these vaccines has been treated in a way that makes it not cause disease, but still elicits an immune system response that recognizes and protects us against the real or wild virus,” Dr. Rinderknecht says.

How quickly the body can build up immunity depends on a lot of factors, including age, the type of vaccine being given, maternal antibodies, genetics, nutritional factors and coexisting diseases.

“The annual flu vaccine takes about two weeks to become effective. However, the initial DTaP (Diphtheria, Tetanus, and Pertussis) vaccine for infants takes a series of three doses, two months apart before it’s effective. The mRNA COVID-19 vaccines take two doses before maximum protection is reached,” Dr. Rinderknecht says.

It’s important to follow the advice of your doctor and get the recommended doses of all vaccines in order to have the highest immunity to the disease. If you have questions or concerns about any vaccine, talk to your doctor.

Why are Vaccines Important?

“If a high level of the population is vaccinated, a contagious individual introduced to the community will not result in the spread of the disease. However, if there is a low vaccine rate, the disease will spread among those in which the vaccine wasn’t effective (and those too young or too compromised to be vaccinated),” Dr. Rinderknecht says.

He identifies three main reasons why vaccines are important.

• Decreases the transmission of disease
• Prevents suffering and death to ourselves or loved ones from an avoidable cause
• Reduces the chances of having the financial burden of medical cost associated with disease conditions

“The only disease totally eliminated from vaccination is smallpox. The next closest to elimination is polio. It has been eliminated from the Western Hemisphere since 1991, but still lives on in a few countries in Asia. International travel allows many diseases to be just a stroll away at the local market,” Dr. Rinderknecht says.

However, it is still possible for you to get the disease after being vaccinated.

“No vaccine is 100 percent effective—for example, the MMR (measles-mumps-rubella) is 95-97 percent effective against measles. Our annual flu vaccine varies from 25-70 percent effective. Often, a vaccine may not totally prevent a disease, but will alter and reduce the severity so you don’t get really sick,” Dr. Rinderknecht says.

How is Vaccine Safety Testing Completed?

To make sure a vaccine is both safe and effective, it must first go through a series of tests before it can be licensed for public use. The U.S. Food and Drug Administration oversees these tests, which are called clinical trials. The trial must involve more than 10,000 people. In this testing, some people receive the new vaccine and others get a placebo, or an inactive treatment. Then, the researchers track what happens.

“Once a vaccine is licensed and recommended, it can safely be distributed to people. But the monitoring doesn’t stop there – it becomes even more robust. For example, extremely rare side effects may not be discovered in a study of 10,000 to 50,000 people. But, when used in the general population with millions being monitored, those rare side effects will be discovered. This is expected and a normal part of scientific discovery,” Dr. Rinderknecht says.

The CDC and the FDA work together to closely monitor vaccines after they are distributed to the public. If new risks or side effects are discovered over time, vaccine recommendations could change.

“After enough of the public is immune, either through infection or vaccination, we’ll reach what’s called herd immunity. The percentage of people who need to have protection in order to achieve herd immunity varies by disease. For COVID-19, there is no magic number for when we’ll reach this status,” Dr. Rinderknecht says.

Why is it Important to Immunize Your Child?

Some caregivers worry about the vaccination schedule for very young children. If you’re worried about autism, Dr. Rinderknecht says don’t be.

“No vaccine is associated with causing autism. Now with about 100 studies, this is becoming a dead issue,” Dr. Rinderknecht says.

Here are three reasons it is important to stick to the vaccine schedule provided by your care team:

• Backed by science. There is data to support the safety and efficacy of vaccines when they are administered together. There is a lack of data on alternative schedules.
• Better protection. When a schedule is spread out, immunity is delayed and that infant won’t be protected if he/she encounters the disease. Following the vaccination schedule supports the health of your child.
• Right vaccinations, right time. By sticking to the recommended schedule, there’s no guessing by you or your care team if your child is receiving the right vaccinations at the right time

Dr. Rinderknecht says some parents or caregivers are concerned with the HPV (Human Papillomavirus) vaccine. While inaccurate information has led some to believe the HPV vaccine isn’t safe, he says it is. The truth is it can prevent cervical cancer in girls and protect both boys and girls from several other common cancers including both throat and neck cancers, anal cancer and genital warts.

“HPV is the most highly tested of all vaccines. It’s been used for over a decade and over 100 million doses given with no long-term side effects,” Dr. Rinderknecht says.

Another vaccine parents are asking doctors about is the COVID-19 vaccine. 

“It’s very important for children to be immunized for COVID-19. We know it’s a vital step in minimizing the spread of the virus, keeping our communities healthy and ending this pandemic,” Dr. Rinderknecht says.

If you aren’t sure what vaccines your child needs and when, call your UnityPoint Clinic doctor—they can help.