Everything you need to know about COVID-19 vaccines

Rachel Grumman Bender
·5 min read

As the newly approved Pfizer COVID-19 vaccine is rolled out to high-risk groups across the country — soon to be followed by Moderna’s — Yahoo Life spoke with Dr. Dara Kass, an associate clinical professor of emergency medicine at Columbia University and a Yahoo Life medical contributor, to clear up any confusion and talk about everything people need to know about the COVID-19 vaccines.

“It’s really important that we don’t let intentional misinformation and disinformation distract people from what we know,” Kass tells Yahoo Life. “This is both a safe and effective vaccine.”

How effective are the vaccines?

Pfizer’s vaccine is 95 percent effective against the coronavirus and is approved for people 16 and older. Moderna reports a 94.5 percent efficacy rate for its vaccine and is approved for adults 18 and older.

In clinical trials, “thousands and thousands of patients got each of these vaccines to prove that they are both safe and effective and ready for primetime to be given to people like me and you,” says Kass.

Both the Pfizer and Moderna vaccines require two shots: For Pfizer, the shots are spaced three weeks apart, while Moderna’s are four weeks apart.

Kass explains that “the best data we have” show that 10 days after the second vaccine is when you can consider yourself “truly protected” — which means that every patient who gets their first vaccine “should have a very clear plan for when they’re going back to get their second dose.”

The vaccines have not yet been approved for use in young children. Moderna announced on Dec. 10 that its COVID-19 vaccine trials would include adolescents 12 to 17 years old. Pfizer announced in a statement that it will continue its COVID-19 vaccine research on adolescents 12 to 17 years old, and plans for additional studies to evaluate its COVID-19 vaccine in “pregnant women, children younger than 12 years, and those in special risk groups, such as the immunocompromised.”

Here are the answers to all your questions about the two coronavirus vaccines. (Photo: Getty Images)
Here are the answers to all your questions about the two coronavirus vaccines. (Photo: Getty Images)

How does the vaccine work?

Both the Pfizer and Moderna vaccines use messenger RNA technology to trigger an immune response.

“What that means is that you get injected with a blueprint of what a protein that’s on the outside of the coronavirus would look like,” explains Kass, “and your body takes that blueprint and immediately translates it to make a protein. That blueprint then goes away. Your immune system sees this foreign protein and says, ‘Hey, it's not supposed to be here.’ It mounts an immune response to that protein, and that immune response is what happens after you’re vaccinated.”

Kass explains that both the Pfizer and Moderna vaccines have a booster, “meaning that you have to have a second shot after the first shot,” she says. “The idea is that, after your body sees this foreign protein and makes this antibody response, now the next time you get the vaccine, you have a good, sustained immune response to the coronavirus.”

Are there side effects?

“We know the vaccine has side effects similar to any time your immune system kicks up,” says Kass. Side effects include pain at the injection site, fatigue, headache, muscle pain, fever, chills or joint pain, particularly after the second shot. But most of the side effects were categorized as mild or moderate. Side effects typically occur one or two days after injection and last for one to two days, according to Moderna. The Centers for Disease Control and Prevention recommends that anyone with a history of anaphylaxis — an acute and potentially life-threatening serious allergic reaction — should be monitored for 30 minutes after receiving a COVID-19 vaccine.

Kass clarifies that the side effects from the vaccine are not a “micro-infection” of COVID-19 “because the vaccine itself doesn’t give you the coronavirus.” If you’re feeling side effects after receiving the vaccine, such as soreness or a headache, Kass says, “that’s to be expected,” adding: “That is your immune response taking care of your body.”

To help reduce side effects, Kass recommends taking an over-the-counter pain medicine after getting the vaccine, along with taking the next day off from work, if possible, “just in case they have side effects.”

How will the vaccines get distributed?

COVID-19 vaccines are currently being distributed to frontline health care workers, as well as residents and staff at long-term care facilities. “Right now, the recommendation is that everybody in a risk group should get vaccinated regardless of previous infections of COVID-19,” says Kass.

After those high-risk groups are vaccinated, it will be a “state-by-state decision,” says Kass, as far as which groups will go next. But the next groups most likely to follow are essential workers, people 65 and older, and those with health conditions, such as diabetes and obesity, that make them more vulnerable to severe COVID-19 illness.

Do you still have to wear a mask and practice physical distancing after getting the vaccine?

For the time being, yes. “There is no evidence that this vaccine should serve as a ‘Get out of jail free’ card for anybody right now,” says Kass. “We know it protects the person that was vaccinated from getting sick and dying, but it does not yet prove whether or not you can give the virus to somebody else.”

For now, Kass tells people to “be smart, wear a mask and stay home as best you can until enough people are vaccinated that we can consider ourselves to have herd immunity.”

She adds: “Together we can do this.”

For the latest coronavirus news and updates, follow along at https://news.yahoo.com/coronavirus. According to experts, people over 60 and those who are immunocompromised continue to be the most at risk. If you have questions, please reference the CDC’s and WHO’s resource guides.

Read more from Yahoo Life

Want lifestyle and wellness news delivered to your inbox? Sign up here for Yahoo Life’s newsletter.