covid-19 vaccine

Everything Parents Need to Know About the COVID-19 Vaccine

A roundup of answers to all of parents’ pressing questions!

by Steve Silvestro, MD  @zendocsteve

You can also listen to this article as a podcast on your favorite podcast app or click on the player below:


We’re finally here.

After nearly a year living through a global pandemic, with fear and uncertainty hanging over us with every decision, we’re on the cusp of what we’ve all been hoping for: a vaccine.

As I write this, select healthcare workers are receiving their first dose right now. And while it may be several months before everyone has an opportunity to get their own first dose—and perhaps several more before it’s available to their kids—parents have begun asking me plenty of questions about whether or not the vaccine is right for their families.

I can’t blame them. We’re all excited about the prospect of protecting ourselves and our loved ones from this virus. But any time a new vaccine comes to market, parents have concerns—and with this particular vaccine using a new technology, and with limited data on kids, teens, and pregnant or breastfeeding moms, there’s a lot to weed through.

So I’m going to attempt to make this as complete as possible—your one stop for everything you’ll need to know about the vaccine and your family based on what we currently know.

A few housekeeping notes before we dive in:

  • SARS-CoV-2 is the name of the virus; COVID-19 is the name of the disease it causes in humans. For simplicity, I’m going to use the term COVID throughout this article.
  • All of the information below pertains to the Pfizer- BioNTech vaccine because that is what was currently approved for emergency use in the United States at the time of writing (December 14, 2020). All data regarding effectiveness, safety, and study participants can be found here. The Moderna vaccine is expected to be approved on December 17 and has been determined to have similar data, which can be found here.


The really cool thing about this vaccine (science nerd hat on!) is that it uses a new approach that hasn’t traditionally been used in vaccines before.

Most vaccines contain pieces of a virus or bacteria, while a few contain live viruses. Once these pieces or viruses are injected, your body recognizes that they don’t belong inside of you & the immune system responds. Antibodies are made to recognize those viral or bacterial pieces, and other immune cells learn to attack them, too.

But the first COVID vaccines that will be available use a whole different approach. Instead of whole viruses, bacteria, or pieces of them, these vaccines use mRNA wrapped in a “lipid nanoparticle.”

What’s the Deal with mRNA?

If you think “mRNA” sounds a lot like “DNA,” you’re right. Think of DNA as the master blueprint of a genetic code—it contains the plans to make every single protein an organism or virus needs. Messenger RNA (mRNA) is essentially the courier that contains a small piece of code for a specific protein sequence and brings it to the part of a cell that, like a factory, reads the messenger’s code and manufactures a protein.

The COVID vaccine contains a very special mRNA—the mRNA that codes for the virus’s “spike protein.” The COVID virus uses this spike protein to latch onto and break into our cells, leading the way for rampant infection. After the vaccine is injected into your muscle, the spike protein mRNA code is read by your muscle cells’ protein factories and they start making the COVID spike protein inside your cells.

Of course, the COVID spike protein doesn’t belong in our bodies! Soon after your muscle cells start producing it, your immune system recognizes that the spike protein doesn’t look like a normal thing to float around in your bloodstream and begins to make antibodies against it. Antibodies are essentially puzzle pieces that stick onto the spike protein you’ve made and then call over other immune cells to gang up and start attacking it. By teaching your immune cells to make antibodies and recognize the spike protein, your immune system gets geared up to attack and neutralize the COVID virus if it ever tries to infect your body—giving you immunity.

Why mRNA?

A few paragraphs back, I said that the most common vaccines contain pieces of a virus or bacteria to elicit the body’s immune response. So why doesn’t the COVID vaccine use the spike protein itself rather than the mRNA for the spike protein?

Well, there are indeed companies working on a COVID version of this more traditional approach. But it’s much faster and much easier to mass produce mRNA than actual viral proteins—and since speed is of the essence to stop this pandemic, a handful of companies and countries put their eggs in the mRNA vaccine basket. Lucky for us, it seems like it was a gamble that’s now paying off with a highly effective, easy to make vaccine.

It’s important to point out that this COVID mRNA particle in the vaccine breaks down within minutes inside our bodies. It also doesn’t do a thing to your actual human DNA. So while some people are trying to raise a bit of fear about this vaccine by saying that “you’re injecting genetic material into your body,” the reality isn’t quite so scary. In fact, the chicken you ate for dinner last night was chock-full of genetic material and is sure to hang out inside your body many hours after this mRNA would have already broken down.

One More Difference—the “Lipid Nanoparticle”

There is another thing that sets this vaccine apart from traditional vaccines—the lipid nanoparticle (LNP).

Our cells are pretty good at keeping most things out. That’s why viruses have to get sneaky—for example, the COVID virus spike protein basically uses a keyhole that our cells usually use for compounds our bodies naturally make. But there is no keyhole for mRNA—so if we want the spike protein mRNA to get inside our cells and use our protein factories, we have to get sneaky, too.

The LPN does exactly that. Essentially a sphere of fatty particles, the LPN can slip inside our cells pretty easily. Put the mRNA inside that sphere and we now have easy entry for the vaccine’s mRNA before it would have otherwise gotten broken down. Think of the LPN as the “cookie” part of a fortune cookie—sure, the fortune inside is the important part, but it’s the cookie that makes the fortune appealing!

It’s essentially new technology to use the combination of a lipid envelope with mRNA for a vaccine. It was written about in 2016, first approved for use in medications in 2018, and now used for the first time in prophylactic vaccines here in 2020. Like mRNA, LPNs are very promising tools for vaccines because of how easy it is to mass produce them and their apparently good safety profile.


Alright, so here’s the important part: Does the vaccine actually work?

Yes—and even better than expected.

The vaccine is given as a two-dose series, with the second dose given 3 weeks after the first. Expectations were that the vaccine might be 60-70% effective (which is what has been seen with the AstraZeneca version).

Amazingly, by 7 days after the second dose, the Pfizer vaccine is 95% effective (the Moderna vaccine is 93% effective, but measured at 14 days after the second dose). That’s a game-changer. Some questions remain as to how long immunity will last—we have some guesses, but really only have a few months’ worth of data—but if a significant portion of the population receives a 95% effective vaccine, that’s going to blow a giant hole in the pandemic.


With any vaccine, there is always the chance of side effects. In fact, most side effects that adults and kids experience with vaccines are simply a result of the immune system turning on. When people claim they “got the flu from the flu shot,” it’s impossible—no flu shot contains live flu virus.

So what causes someone to feel under the weather after a vaccine? Much of the same immune response you get to help you fight a cold is what turns on to help respond to—and build immunity from—a vaccine. But unlike a cold in which your body is fighting an active infection that is trying to replicate inside of you, a vaccine like this one contains only a small amount of material for you to respond to. The result is that most side effects last for roughly 24 hours or less.

Side effects listed in the FDA report for the Pfizer vaccine include:

“…pain at the injection site (84.1%), fatigue (62.9%), headache (55.1%), muscle pain (38.3%), chills (31.9%), joint pain (23.6%), fever (14.2%), injection site swelling (10.5%), injection site redness (9.5%), nausea (1.1%), malaise (0.5%), and lymphadenopathy (0.3%).”

This study included nearly 44,000 people—half getting the vaccine and half getting placebo. When the vaccine rolled out after the study, there were two individuals (at time of writing) who developed severe allergic reaction. The CDC initially warned that people with a history of severe allergies may wish to speak with their providers before getting the vaccine, but has since changed that stance to state that only people who’ve had an allergic reaction to the first dose or ingredients in it should avoid getting it.


This is the biggest question I’ve had from parents lately—and, unfortunately, the answer is: “Not much.”

Out of the 44,000 people in the Pfizer vaccine study, the only people younger than 18 years of age were 283 teens who were 16-17 years old. As of time of writing, there are currently 86 teens aged 12-15 in the study, as well—but because they were only enrolled in the study after October 15th, there wasn’t much data on them at the time of the FDA emergency approval.

Unfortunately, more widespread testing in kids isn’t likely to happen until early 2021. And while there is a possibility that governing bodies around the world will allow emergency approval before then without the testing data—this does happen with many medications, they’re tested in adults and approved for kids—the best thing most families can do for now is to protect their kids by vaccinating the adults and older teens around them.


For a whole host of reasons, pregnant and breastfeeding moms are often kept out of clinical trials. This has been true of the COVID vaccine trials, as well, and it’s been a point of great contention with many women’s health groups strongly advocating that pregnant and nursing moms be included.

The CDC Advisory Committee on Immunization Practices (ACIP) met in October, and while they didn’t come to a consensus, a majority of members agreed that a vaccine meeting the criteria of the Pfizer and Moderna vaccines should be okay to give to breastfeeding mothers. In fact, nearly all other vaccines are allowed to be given to breastfeeding moms, save for the smallpox vaccine.

With regard to pregnancy, we still don’t have any real data to use. Moderna reported that 13 women became pregnant during the trial, one of whom had a miscarriage—and she had received the placebo, not the vaccine.

At that same October meeting of the CDC’s ACIP, a majority of the members agreed that being pregnant shouldn’t be a reason not to get the vaccine. Instead, they felt it should be considered a “precaution”—meaning that a pregnant woman should speak with her physician about whether or not it makes sense for her particular situation. As for women who get pregnant after they get the first dose but before they get the second, a majority of Committee members agreed that it should be considered safe to give the second dose—though there were some members who proposed postponing the second dose until the second trimester or after pregnancy altogether.

There is some variability in these opinions around the globe. Canada’s health body is taking a stance similar to the CDC—advising that pregnant women should be able to get the vaccine. The UK is taking a more cautious approach, with their version of the FDA releasing a statement on December 6th advising pregnant women not to get the vaccine until there is more data available.

Ultimately, the wisest thing to do is to talk with your healthcare provider about what makes sense for you.


In a way, some of these questions are a bit moot right now because a majority of parents won’t have access to the vaccine for another few months.

Distribution of the vaccine is going to broken down into “phases” based on different groups’ risks of contracting COVID infection. Phase One—which has already begun—includes first responders, high-risk healthcare workers, seniors living in assisted care facilities, and some people with medical conditions that put them at high risk for severe illness if they contract COVID.

Phase One is likely to continue through at least January, and at the moment there are proposals but not definitive guidelines on who should be in Phases Two, Three, and Four and when these Phases will begin.

So, for parents who work in healthcare and other essential fields, the question of whether to get the vaccine is a bit more pressing. Fortunately, they can look to the fact that this early data on both safety and efficacy is really promising. Personally, I also appreciate the fact that there are multiple companies working on essentially the same vaccine—meaning that we’re basically getting far more clinical trial data than we usually would when a single vaccine comes to market.

But for parents who aren’t in the early distribution phases—as well as everyone’s kids and teens—the opportunity to get the vaccine is still likely a few months away. And while that might be somewhat frustrating, the benefit is that there will then be data on hundreds of thousands of vaccine recipients by then, ideally quashing any worries about how safe or effective the vaccine really is.


This pandemic has been a grueling time filled with heartache for many, and anxiety for all. We aren’t out of the woods yet—even with the vaccine beginning to roll out, we’re likely to see infection numbers and deaths climb through February of 2021, so keep wearing your mask and avoiding indoor gatherings.

But there is a light at the end of this long tunnel—and it finally feels like that light is within our grasp…

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