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Frequently Asked COVID-19 Vaccine Questions

Effective vaccines against COVID-19 have been available since December 2020. With the Delta variant circulating around the world, do the vaccines still work? Is one vaccine better than another? Will I need a booster shot? Infectious disease and global health expert Carlos del Rio, MD, of Emory University and Chief Health Officer at University of Michigan Preeti Malani, MD, MSJ, answer your questions.

• Vaccines have only been available in the US since December 2020, so how do I know they're safe long-term?

• What is the Delta variant? And should I be worried?

• I'm vaccinated. Am I protected against the Delta variant?

• What is a breakthrough infection, and should I be worried?

• Are all breakthrough infections due to the Delta variant or is something else going on?

• Will I need a booster dose later this year or next?

• Should I avoid the Johnson & Johnson/Janssen vaccine, or the AstraZeneca vaccine? Are some vaccines better than others?

• I had COVID and have long-haul symptoms. Will vaccination help or make them worse?

• How long am I protected?

• What can I do after I'm fully vaccinated?

• Should I be vaccinated if I still need to wear a mask and physically distance afterwards?

• If over half of people are vaccinated, why do I still need to take it?

• I've had a severe reaction to a vaccine before. Is the vaccine safe for me?

• I've heard a lot about bad vaccine reactions, including deaths. What are those? And should I be concerned?

• Can I use over-the-counter painkillers to treat the side effects of vaccination?

• I'm pregnant. Do we know if the vaccine is safe for those who are pregnant or breastfeeding?

• I'm immunosuppressed. Will the vaccine still protect me?

• My child is over age 12; is the vaccine safe for them?

• Should I worry about my unvaccinated young children returning to school?

• Will children under the age of 12 be eligible for the COVID vaccine?

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Transcript

EG: Vaccines have only been available in the US since December 2020, how do I know they're safe long-term?

PM: At this point, hundreds of millions of doses have been given all over the world with just a small number of serious safety concerns on the order of one or two per million, and historically side effects to vaccines, they occur early.

CD: Side effects of vaccines don't happen years later, they happen in the first couple of weeks after receiving a vaccine.

PM: Ultimately even with some unknowns, getting a COVID-19 vaccine is still safer than getting COVID.

EG: What is the Delta variant? And should I be worried?

CD: The SARS-CoV-2 virus is an RNA virus, and RNA viruses, especially respiratory RNA viruses, continuously are mutating and they need to be replicating in order to mutate. And right now we have uncontrolled transmission globally. What is unique about this variant is that it is very transmissible. The amount of virus that an infected person has in their secretion is a thousand times higher then with the previous variants, and what that leads to is that in the original virus, one infected person transmitted to about two and a half to three other people. We call that the R-naught, or the reproductive number. With the Delta variant the R-naught is probably around six, maybe eight. And that means it's so much higher.

So, if it's six, one person infects six, and six then infect, each one of them infects another six. So now after two cycles, you've got 36 and you can go on, and on, and on, and do the math. And pretty soon you realize exponential growth is bad. So that ability to transmit to others makes it very concerning.

EG: I'm vaccinated. Am I protected against the Delta variant?

CD: The vaccines, the mRNA vaccines, the adenovirus vector vaccines are excellent against the Alpha variant. I would say they're pretty good against the Delta variant. They're very good protecting you against severe disease and death. Not as good at protecting you from infection.

And, in fact, they're not good if you just got one dose. With the RNA vaccines, you need to be fully vaccinated. You need to have received two doses. Now, if you've gotten two doses, you have a pretty good level of protection against severe disease and death. And you have a reasonable level of protection against infection.

In our country, the other vaccine we have is the Johnson and Johnson, which is adenovirus vector vaccine. And there's conflicting information. Some studies suggest that it's not as good as other studies that is just as good as the mRNA vaccines, but all those studies come from laboratory studies. We have very little patient outcome data.

Now, not as many people have gotten vaccinated in the US with the Johnson and Johnson vaccine. But the one thing I can tell you is, we're not hearing about enormous amounts of breakthrough cases with people in the Johnson and Johnson vaccine. So, I think the protection is also very good.

EG: What is a breakthrough infection, and should I be worried?

CD: Once you have been fully vaccinated, you can still get infected. And we call that a breakthrough infraction. It's a breakthrough because the virus broke through that barrier that you have from the vaccine, that protection, then you have, that's why it's called breakthrough infection. And the great majority of breakthrough infections are mildly symptomatic, or symptomatic to the point that you have, you feel like you have a bad cold or the flu for two or three days. Occasionally, somebody with a break from infection will be sick, and will end up in the hospital, and may even die. But those numbers are very, very small. I mean, the chances of a fully vaccinated person dying from a breakthrough infection covered it's about 0.0003%. I mean, it is very low.

EG: Are all breakthrough infections due to the Delta variant or is something else going on?

CD: At this point in time, 90% of the strains circulating in this country are Delta. So, right now they are all mostly due to Delta, but when we have more Alpha we saw some breakthrough infections from Alpha.

Again, it really depends on what's circulating and what's in the environment what's circulating is what you're going to have breakthrough infections with.

EG: Will I need a booster dose later this year or next?

CD: You know, it's a very good question. I think at this point in time, I'm not sure you're going to need a booster, but there's clearly evidence that over time, the protection that you have against the virus wanes.

Now, part of it may be just because we have a different virus. Now, the virus changes. So, the degree of protection you need changes. So, would you need a booster? I think you may need a booster, but it may not be a booster with the vaccine you originally got. It may be a booster with a vaccine that is more geared to protecting you against Delta or protecting you against some other variant.

EG: Should I avoid the Janssen/Johnson and Johnson vaccine, or the AstraZeneca vaccine? Are some vaccines better than others?

PM: So, all of the available vaccines are protective against serious infections. So, hospitalizations and deaths. Overall, people should feel confident in any of the available vaccines, including the J and J vaccine and, around the world, the AstraZeneca vaccine.

There have been reports of very rare, but serious, potentially life-threatening, side effects from these two vaccines. And I want to emphasize, these are very rare effects, probably on the order of a few per million. So in most cases, the benefits of the vaccine outweigh the risks because these actions do protect against severe COVID infection, which is a much higher risk.

There are benefits to these two vaccines. The Johnson and Johnson, for example, is a single dose. Neither of those vaccines have the kind of storage requirements in terms of temperature that the mRNA vaccines have. So, it's easier to take the vaccine to people's homes or to get to people who can't access healthcare regularly.

And in the United States, there aren't issues with vaccine supply. So, for anyone who's concerned, I'd recommend the mRNA vaccines. And as we learn more, the recommendations might shift.

EG: I had COVID and have long-haul symptoms. Will vaccination help or make them worse?

CD: There's anecdotal reports. So, people said, I'd have I had COVID and have long COVID, and after I got vaccinated, I'd feel better, but we still need to see data. I think, the anecdotal reports, it's interesting. I don't think long COVID is a contraindication to vaccination. It may help you, but it may not. We really don't have the data.

EG: How long am I protected?

PM: COVID-19 is caused by a novel virus. And the vaccines are of course also new. So, we don't know for sure how long protection will last. But what we know so far is really encouraging. At six months, the level of protection that can be measured, remains high, and the actual protection could be much longer. And we'll find out over time.

EG: What can I do after I'm fully vaccinated?

CD: Recently, the CDC changed its guidelines and CDC said, because of the Delta variant, and because we're seeing an increase in cases, and some of those cases vaccinated people maybe the ones causing the infection, we recommend that people, even if you're fully vaccinated, you still should wear a mask in public places.

And if you've been exposed to somebody with COVID, you should be tested three-to-five days after exposure to be sure that you didn't get infected. I still believe that if you're fully vaccinated you're much more protected and if you're not. So, you can resume life and at this point in time being fully vaccinated, all you can do, I think, is feel pretty good that even if you get infected, you're not going to end up in the hospital and you are not going to get very sick with it. EG: Why should I be vaccinated if I still need to wear a mask and physically distance afterwards?

CD: Before the Delta variant, when you were vaccinated, you were unlikely to get infected. And even if you got infected, you were unlikely to transmit to others because the amount of virus that you had in your secretions was very low.

One of the things that has been disturbing with a Delta variant is that you're still unlikely to get infected, but if you get infected, the amount of virus in your secretions may be as high as if you were not vaccinated. And therefore, what CDC is telling us is, look, even vaccinated people need to wear a mask because you'll may get infected and transmit to others.

EG: If over half of people are vaccinated, why do I still need to take it?

CD: Well, because that's not enough to get to herd immunity. I've seen some recent data suggesting that while cases are coming down in the US they're not coming down as fast in people who have not been vaccinated. In fact, increasingly the cases I'm seeing in the hospital and clinics are people who have not been vaccinated.

PM: There's not a magic threshold. Rather, it's an incremental thing. Every single person who gets vaccinated makes it better for all of us. And the risk of COVID is not going to get to zero anytime soon. There are going to be new cases, and some will be severe, and those are mostly going to be in people who are not vaccinated.

EG: I've had a severe reaction to a vaccine before. Is the vaccine safe for me?

PM: For anyone who has had a serious allergic reaction to vaccines in the past, they do need to be extra careful. And if you've had an allergic reaction to any of the mRNA vaccines, you shouldn't get the second dose. My recommendation as always is to talk to your own doctor about how you can safely get vaccinated.

EG: I've heard a lot about bad vaccine reactions, including deaths. What are those? And should I be concerned? CD: These vaccines are exceedingly, exceedingly safe. What people call bad vaccine reactions tends to be a fever, malaise that tends to last 24-to-48 hours. CDC has received, so far, reports of some deaths, not many, but again, when they've investigated those deaths, almost none have anything to do with the vaccine.

EG: Can I use over-the-counter painkillers to treat the side effects of vaccination?

PM: If you have side effects after vaccination, my advice is to go ahead and take low doses of over-the-counter pain relievers. If you don't need them, don't take them. There's a theoretical concern that you might dampen the immune response, but I would say go ahead and take a small dose because the side effects can be pretty severe in some people.

EG: I'm pregnant. Do we know if the vaccine is safe for those who are pregnant or breastfeeding?

PM: So, when you're studying a new drug or vaccine, you don't usually test it on anyone who's pregnant. So, this was a gap in the early vaccine trials, but since the emergency use authorization, there've been tens of thousands of individuals who were pregnant or become pregnant shortly after vaccination, and the good news is vaccination is safe and protective. Specifically the rates of pregnancy loss, premature births, and other complications are comparable to what you would normally see. Vaccination did not increase these complications. Vaccination is also safe with breastfeeding.

CD: And, on breastfeeding, what we've learned from recent studies is that there's also passage of maternal antibodies to the baby through breast milk.

PM: My recommendation, if you are pregnant, or thinking about getting pregnant, get vaccinated.

EG: I'm immunosuppressed. Will the vaccines still protect me?

CD: Immunosuppressed people, I tell them for them, the vaccines are just as safe as for anybody else, but they may not be as effective. Immunosuppressed people, depends on the kind of immune suppression, may not be as protected as people who have normal immune systems.

So, what I tell immunosuppressed people is don't assume that just because you're vaccinated, you're protected; and continue using your mask, socially distancing, and doing the kinds of things that will help you not get infected.

PM: I encourage anyone in your household who is eligible to be vaccinated to do so as a way to make it safer for you. And there are studies ongoing to see if a different dose, or even more doses, might help boost that response to vaccines.

EG: My child is over age 12. Is the vaccine safe for them?

CD: 100% safe, and, not only safe, but incredibly effective. We learned recently from the results of studies by Pfizer and Moderna in teenagers, in kids between the ages of 12 and 18, showing that the vaccine was incredibly safe, but also incredibly effective. Efficacy, close to a 100%. In fact, more effective than in adults.

PM: And just like any vaccine, children can have some mild side effects like a sore arm or fatigue. And in general, the symptoms are gone within a couple of days, and there's no evidence that there are serious side effects children.

EG: Should I worry about my unvaccinated young children returning to school?

PM: So, my approach throughout the pandemic has been to focus on what we can do instead of what we can't do.

And I hear concerns from parents of children under 12 who are not yet eligible for vaccination. And I always tell them the following. COVID is not the only risk to your health. Getting kids back to the classroom is essential both academically and socially. And the way to keep them safe is by keeping community spread of COVID in check. Everyone else in the child's unit should be vaccinated.

Remember, vaccination is not just about protecting you. It's about protecting everyone around you and masks and good ventilation are really important too. CD: In the CDC recommendations regarding schools, they recommend that everybody in the school, whether it's teachers or students, should be masked. But I want to emphasize, again, CDC, didn't say this, but I want to say it over and over, anybody over the age of 12, but also teachers, should also be vaccinated.

The more vaccinated people you have, the less likely you are to having infections.

EG: Will children under the age of 12 be eligible for the COVID vaccine?

CD: The clinical trials are taking place right now, and we will probably have the results maybe somewhere around October, November, and then when they present it to the FDA.

That's why I said my estimate is that by late December, early January, the kids under the age of 12 will be eligible for vaccination.

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