Masked hand holding a vial of COVID-19 vaccine masked hand holding a vial of COVID-19 vaccine

Ask a doctor: COVID-19 vaccines

Posted: MAR 3, 2021

it’s official: After nearly a year of staying home, perfecting hand hygiene, and pushing through quarantine fatigue, the highly anticipated COVID-19 vaccines are here. Whether you want to understand the basics of how vaccines save lives or learn more about general immunization safety, we’re here to help.

Matthew F. Daley, MD, a pediatrician and vaccine researcher at Kaiser Permanente Colorado’s Institute for Health Research, answers some common questions about the COVID-19 vaccine. Daley serves as a technical consultant on vaccine safety to the Centers for Disease Control and Prevention’s (CDC) Advisory Committee on Immunization Practices. Since he’s part of a team of doctors and scientists advising on vaccines to fight COVID-19, he has the inside scoop on all your biggest questions.

Q: How do the COVID-19 vaccines work? Are they safe?

A: Like most vaccines, the COVID-19 vaccines were created to prevent a virus from attacking the body. They’re designed to make your immune system respond and develop immunity. The vaccines were tested in big populations, so there’s significant data that the vaccines are effective and safe.

What’s new and different about the COVID-19 vaccines is they both use mRNA technology. Instead of putting a weakened virus or smaller parts of a virus into our body, they teach our cells how to make a protein that triggers the same immune response to fight COVID-19.

The data shows that these vaccines are highly effective, and they’re held to the same rigorous safety and effectiveness standards as all other vaccines.

Q: Is it important to get a COVID-19 vaccine when it’s widely available? Why?

A: When the vaccine becomes available to the general public, there will be recommendations at the national level and from the CDC as to who should get it and when. Kaiser Permanente will also have a recommendation about when you should get the COVID-19 vaccine. And doctors will advise their patients and lead by example.

I believe it will depend on an individual’s personal concerns and comfort level if they decide to get it. I’ve studied vaccine safety for the last 10 years, and I personally will get the vaccine. As individuals, we’ll each need to weigh the benefits and risks. I believe the benefits of protecting yourself and your loved ones from COVID-19 outweigh any risk.

Q: What does herd immunity mean, and how does it work?

A: I prefer the term “community immunity” over “herd immunity” because it supports the idea that we have a social responsibility to not spread the virus in our communities. Both terms mean that when enough people in the population are immune, the virus won’t spread even if a few people get sick. It stops at those few people. With community immunity through vaccines and people recovering from COVID-19, the virus will spread less and less. So, when deciding whether to get the COVID-19 vaccine, it’s important to remember that what we do affects our community, not just our household.

Q: What will the COVID-19 vaccine mean for households with children, since no vaccines have been approved for children yet?

A: Because adults have generally been shown to get sicker from COVID-19 than children, these first vaccines were developed for adults. COVID-19 vaccine trials for children have begun. But until those vaccines are ready, the adult vaccines will help slow the spread in households and in the community. With safe and effective vaccines, we’ll get closer to the point where our kids can go back to school, and we can get back to everyday activities like seeing friends and family.

Editor’s note: Information on the types of vaccines and which ones are available changes periodically. For more information on the vaccine, visit

Get the latest updates on the COVID-19 vaccine

We understand how stressful it can be as you wait for a vaccine for yourself and your loved ones. Please know that Kaiser Permanente is moving as quickly and efficiently as possible to vaccinate all our members.