Editor's note: Information on the COVID-19 crisis is constantly changing. For the latest numbers and updates, keep checking the CDC's website. For the most up-to-date information from Michigan Medicine, visit the hospital's Coronavirus (COVID-19) webpage. 

Vaccines are one of the greatest achievements of modern medicine and have saved billions of people from suffering and death. Vaccines provide protection from serious childhood diseases, the flu, many tropical and bacterial diseases and even infections that can cause cancer. And the world is once again looking for a vaccine to help end the COVID-19 pandemic.

But vaccines are also often misunderstood, and some people wonder if they are really necessary or safe.

In a new livestream, Michigan Medicine's Pam Rockwell, M.D., a family medicine physician, answered commonly asked questions about vaccines.

Here are some highlights, edited for length and clarity, but watch the full video of our live Q&A on vaccines for additional information and to learn about herd immunity, egg allergies and vaccines, boosting your immune system and more.

How do vaccines work?

"By stimulating the immune system, tricking the immune system into thinking you've been exposed to a particular germ, whether it's a virus or bacteria. Your body mounts an immune system that stays in your body. The goal is for your body's immune system to get activated if you were exposed to that infection in the future."

How safe are vaccines?

"Vaccines are very safe and have never been safer. They are vetted very well before they ever go out to the public. There might be mild side effects with a vaccine as your immune system gets stimulated, like a sore arm, low-grade fever, a headache, things like that. But the chance of a serious adverse reaction is so, so small compared to the risk you take by getting exposed to a vaccine-preventable disease."

Aren't I risking my kids' health or my health by going to a clinic for vaccines during a pandemic?

"Of course this is on people's mind, especially as we went to total shut down, we saw national vaccine rates fall across the country. Now that different states are in different forms of opening, our primary goal is to catch children, adolescents and adults up on vaccines they're delayed or late on and get everybody vaccinated. We're all following CDC guidelines on how to do this in the safest manner possible. That means all of our offices, public health areas are practicing social distancing, we are screening everybody who comes in to our offices, and are holding separate immunization clinics. We know that an outbreak of influenza in a couple of months could be quite devastating."

Why do we need a new flu shot every year? Is it risky to go to get a flu vaccine this year?

"The flu virus mutates every year. All over the world scientists are studying the flu every year. When flu shots come out it's based on what scientists have been seeing for the last 6-9 months prior. They make their best scientific estimate on what should go into the flu vaccine that year. In children under 8, when they get the flu shot for the first time they need two shots, and then after that it is annual. In children and older adults, your immunity wanes, especially for the flu. It is very important to get a vaccine every year to maintain that immunity, even if it is the exact same flu virus and you got the shot the year before."

"It is ever so important to get a flu vaccine this year with the pandemic for COVID-19. I couldn't be more passionate about this. My fear is if we have even a regular flu this year, not to mention if it's a severe one, and we have COVID still going on, not only is there a risk individually of being sick with both at the same time, but our healthcare system cannot absorb that."

If someone doesn't have a high risk of dying from COVID, for instance children, why should they take the risk of getting the COVID vaccine once it's approved?

"That's assuming there's a risk to the vaccine, and I would argue there wouldn't be a risk. More and more data is coming out about children and we know some children have died from COVID. But it looks like the vast majority of very young children don't get very sick. However, depending on how old they are, they can be a vector to grandma, grandpa, mom, dad, aunt, uncle, everybody. So it stands we need to get our population immune to this virus to protect each other."

When do you think a vaccine for COVID-19 will be ready?

"Personally I think there's a good chance that Dr. Fauci is correct and it may be ready by the end of this year. But that doesn't mean it would be available to everyone then. I think it will be a good year from now before it will become more available."

Access more basic information about vaccines from the Centers for Disease Control and Prevention

Interested in a COVID-19 clinical trial? Health research is critical to ending the COVID-19 pandemic. Our researchers are hard at work to find vaccines and other ways to potentially prevent and treat the disease and need your help. Sign up to be considered for a clinical trial at Michigan Medicine.