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COVID-19 Update 9/15: All About Pfizer Boosters

September 15th, 2021 | 9 min. read

By Steve E. Bishop, M.D.

COVID-19 Update 9/15: All About Pfizer Boosters

This week's COVID-19 update was almost all about Pfizer boosters. Pfizer and the FDA released data on safety and efficacy numbers for a third dose of the Pfizer vaccine this week, and the FDA will discuss the data in a meeting on Friday, Sept. 17.

The CDC's ACIP committee is scheduled to meet next week — Sept. 22 and 23 — and is expected to discuss the data then as well.

Dr. Steven Bishop analyzed some of the things the FDA and CDC will be considering, such as:

  • Are Pfizer booster shots effective? 
  • Are Pfizer booster shots safe? What are the expected side effects? 
  • Does the general population need boosters at this time? 
  • And what about Moderna? 

Watch the video below or read on for the full recap. 

COVID Numbers

First, looking at numbers —both across the country and in Virginia in particular as well — it looks like we probably are on the back half of this Delta surge. Again, we've talked about this a little bit in prior weeks that both in the UK and India, it seemed to follow this 120-day cycle. And I think we're going to follow something pretty similar here.

And I think just looking at the fact that the numbers are plateauing out, I think we're starting the back half of this Delta surge, and it'll start to come down here over the next couple of weeks and go back to a much lower baseline, which is great news.

Why do these surges and waves happen? And then go down. This is the natural history of respiratory viral infections. They're going to continue to come in waves. The hope is that as we get more and more people either vaccinated or immune from infection, that these waves will become smaller and smaller in amplitude, even if we develop new variants over time.

Hopefully, these big waves will continue to get smaller. My guess is we'll have another wave in December/January. That's just my guess based on kind of how things happened last year, but who knows.

This virus seems to kind of do whatever it wants, however it wants. So we're continuing to learn more every day and every week as we watch and see what happens. But again, hopefully, as we get more people vaccinated, more people immune, these waves will become smaller and smaller so that the big humps and surges become less and less of a strain both on the healthcare system and on people's health in general.

Pfizer Boosters: Effective?

Now let's talk about booster shots. This is what everybody wants to talk about. This is what's in the news right now.

I'm going to link to a couple of big documents that I have been able to read through, about half of each. Some of them just came out today. One is from Pfizer for what they submitted to the FDA for their data to approve booster doses for their vaccine, their mRNA vaccine, and one is from the FDA. 

What we've got here in these two big data dumps is Pfizer detailing out the small-scale studies they've done over the past few months to show both the safety and efficacy of a booster dose— a third dose of their Comirnaty vaccine, the mRNA vaccine.

And what they've shown is that when you give the vaccine to people ages 18 and up that you get a good, robust improvement in the antibody response, and you do have an increase in that antibody level after you get the third dose of the vaccine.

Now, these are relatively small studies. We're talking about a few hundred people total across all of the studies that they have done. Now, they showed again, we've got a robust antibody response.

Pfizer Boosters: Side Effects?

When you look at the side effect profile of getting a third dose — there's been a lot of concerns about if we keep giving doses of these things, are we going to get escalating side-effects — and it appears that probably is not going to be the case.

The folks in the studies who got the third dose had side effects at about the same rate as the second dose. Based on that, my guess is that anyone who had side effects for dose two, you're probably going to have similar side effects for dose three.

Side effects didn't appear to be worse or more intense or different in any way with a couple of minor exceptions, perhaps being that a fair number of people had some lymph node swelling that was temporary, particularly in the axilla. And that was a known side effect from both prior shots of Pfizer and Moderna vaccines as well.

We have been following that related to getting your mammogram done for women, because if your lymph nodes are swollen when you get a mammogram, it may throw off the results of the mammogram and create a false positive, and make people think there's something abnormal there, but it was just a reaction to the COVID vaccine.

We've been telling people all along and the radiologists have been saying and tracking, "Hey, when did you get your COVID vaccine?" to make sure that we don't get confused about those lymph nodes being swollen as it relates to breast cancer versus just a normal side effect from the COVID vaccine.

So that's not a new side effect either, just happened to show up at about a 5% rate in these follow-up studies. I don't think that's serious in any way. Having some minor lymph node swelling is usually no big deal. It's a little uncomfortable, but it goes away and doesn't cause any problems.

It's just a sign that your body is reacting to the vaccine and creating an immune response, which is what it's supposed to do. Nothing really concerning there.

Pfizer Boosters: 16 and 17-year olds

Now, what does bother me a little bit about the Pfizer data that they have put out is that they did not study it in anyone under the age of 18 for the booster.

They did not include 16 or 17-year-olds in their studies and this kind of bleeds over into what the FDA is talking about in their documents. 

The big concern with that — that I have and I think a lot of people have including the FDA based on what they wrote in their documentation — is that for younger people, and particularly males under the age of 40 and definitely the 16- and 17-year-old males, there is a significantly increased risk of having myocarditis and pericarditis from these vaccines.

It's on the FDA labeling at this point. It's not something that's really up for dispute. We all pretty much recognize that there is an increased risk of having one of these side effects, particularly for younger men from these mRNA vaccines, the Moderna and the Pfizer, and the FDA makes a point of pointing this out in their initial documentation.

I think they're doing this because they want to make the point that, hey, Pfizer, if you want a booster approved for 16- and 17-year-olds, we really need to see some data regarding how the 16- and 17-year-old men, in particular, reacted to a third dose. And I think that that's why they put that up there in Section 3 of their documentation.

They said, hey, remember, we didn't forget. There is an increased risk here just from the first two doses. We really would like to see what's going on here in this age group, in this population, with a third dose.

I suspect that the FDA is going to be pretty hesitant to approve a third dose for anyone under 18, given that Pfizer hasn't included data from those age groups.

Now, Pfizer basically was trying to say, well, we just extrapolated the data down to 16- and 17-year-olds for the efficacy. And I think that's legitimate and probably fine. And there's no reason to suspect a 16- versus an 18-year-old would necessarily have a lesser immune response to the vaccine.

But I think FDA's going to want to see more safety data on this from Pfizer before they recommend boosters for healthy 16- and 17-year-olds. That's just my take on it.

Pfizer Boosters: Do we need them? 

The big thing that we're going to figure out is on Friday. Do we need the boosters at all?

I think that's the big question that the FDA and the CDC and the ACIP committee are grappling with is, yes, okay, the booster worked in terms of we've got a stronger immune response, but the real question is: do we need them?

The Pfizer data and what they have put out here is fine. It is good data in terms of the third dose is clearly relatively safe and it does increase the antibodies, but these are what are called surrogate markers, right?

Many studies of drugs and treatments over the years have been rightly criticized for putting out data based on surrogate markers. What we need is endpoints, right? When Pfizer and Moderna first put out all their data back in December, the data was all about the endpoints, right?

Infections, hospitalizations, death. The booster doses only followed these people for a month. We really don't have this data for this booster dose yet.

I'm sure more will come and Pfizer, for their outcome data, they're relying on sort of a natural experiment that's gone on in Israel, where Israel started giving booster doses earlier on. And they showed that the population rate for hospitalization and death started to drop again, once the Pfizer third dose was being given out as a booster to folks.

And that's fine, that's corroborative data, but what we need is another trial. We need more trial data to prove that that is truly an effect of the booster dose and not just some other random factor.

Pfizer Boosters: Will the FDA/CDC recommend them? 

I think that based on my read of the FDA's data packet that they put out and based on my read of the Pfizer data packet, I'm not extremely confident that FDA is going to move forward with recommending or approving booster doses.

I think they're going to perhaps say we need more data because the real question is: what is our goal with the boosters?

Are we trying to prevent as many infections as we can realizing that we may continue to have waning infection protection every six months?

Or is our goal to keep people out of the hospital and keep people from dying?

And the FDA states this plainly in the documentation that they put out and they, in fact said, overall, the vaccines appear to continue to perform well at preventing severe disease and mortality.

So there, I think they are trying to signal to folks that they're not overly eager to approve boosters at this time. And now this is their exact quote from page eight of the FDA document.

"Overall data indicate that currently licensed or authorized vaccines still afford protection against severe disease and death in the United States."

There are many potentially relevant studies. FDA has not independently reviewed or verified all the underlying data or their conclusions. Some of this data will be discussed on September 17th. So I think that's really the bottom line on this is: let's wait until Friday. We'll see what the discussion yields amongst the FDA group that's meeting. And we'll see where we go from there.

But these are sort of my takes on the data. Boosters may be helpful. It's not really clear what the goal is with them just yet, and not everyone may need them.

Now, if you go back to the CDC's ACIP data from a few weeks ago, ACIP may take this data and say, okay, great. They appear to be safe for all those people in these very high-risk groups where we did see a decline in their protection from hospitalization and severe disease.

We may go ahead with boosters for those people, the 75 and up crowd, and maybe certain healthcare workers in certain settings, but they don't seem eager to recommend a broad-scale booster dose for the general population.

I wouldn't be surprised if you see that answer come out on Friday and next week, which is no boosters right now. So more to come. We'll see where things land, but that's kind of my take on things as of today.

Mammograms after vaccination

"Just for information, I was told to wait at least six weeks for my second vaccine before getting a mammogram because of the lymph node issue."

Yep, that is exactly correct. And that has been our stable recommendation for about a year now since we discovered that issue.

So anyone who does get a booster of COVID for any reason, if you're in those immunocompromised categories right now, and you're getting a booster, the same recommendation applies. Wait six weeks before a mammogram.

J&J Boosters for Immunocompromised

"Has there been any guidance for boosters or additional shots for immunocompromised people who got the J&J vaccine?"

Great question. I'm glad you brought that up. Yeah, this continues to be an area that is under-discussed, and it's a little bit disappointing.

I think you're going to see the same answer ultimately come out, which is no boosters right now. Based on ACIP's data from a couple of weeks ago, where they were showing that J&J still had robust protection from hospitalization and death, even six or eight months out.\

The protection wasn't quite as good as Pfizer and Moderna, but it was very high and didn't really decline over time in most people. So I think that's great news. That's a good thing for the folks that got J&J.

I think for now I would just say, maybe wait a few more weeks. Hopefully Johnson and Johnson is going to put out some data around this. I know many people were and continue to be more comfortable taking the J&J vaccine because the mechanism by which it works is a little bit different and it's a single shot versus two. I know a lot of people took the J&J vaccine for that reason.

Moderna Boosters

"What about Moderna?"

Yeah, we are waiting on their booster data. They have not released it yet. I think they're running a little bit behind Pfizer on getting their data done.

That's kind of been the case all along. They're a few weeks behind Pfizer on most things. Probably next month sometime we'll see data about Moderna would be my guess.

Immunocompromised Health Issues

"What are some examples of immunocompromised health issues that might need a booster?"

There's a specific list that CDC put out, but it basically is folks who are either being treated for cancer or just recently finished treatment for cancer.

People who have had an organ transplant and are taking immune suppression medicines. People who have untreated HIV disease or other primary immune system problems. Or if they're on steroids or other medicines to suppress the immune system.

There are a few specific categories there that those people should get a booster dose at this time. And that's recommended based on the fact that they probably didn't have a great response to the first two doses.

Next Update? 

Our next update will be Wednesday, September 22, at 1:00 p.m. live on the PartnerMD Facebook page. As always, we will post the full video and complete blog recap on Thursday morning.

Steve E. Bishop, M.D.

As a board-certified internist and concierge doctor in Richmond, VA, Dr. Steven Bishop is passionate about helping his patients improve their lives through better health. He helps healthy adults adjust their lifestyles as they age and helps patients with complex medical diseases manage and improve their health.