COVID-19 vaccine boosters for people in breast cancer treatment, with Pallav Mehta, MD

The Centers for Disease Control and Prevention recently updated its guidance for COVID-19 vaccination, recommending that people with compromised immune systems — which includes people given certain treatments for breast cancer such as chemotherapy — get a third shot, also called a booster shot, of the Pfizer or Moderna vaccines.

To help us understand what that could mean for you, Living Beyond Breast Cancer CEO Jean A. Sachs, MSS, MLSP, speaks with medical oncologist Pallav Mehta, MD, about who is eligible for a booster shot, whom to ask if you think you should get a booster, and how medical centers are adapting to the new recommendations. Dr. Mehta also discusses how experts use new information about the spread of COVID-19 when changing recommendations and how the vaccine works in different populations.

Jean A. Sachs, MSS, MLSP:

Hi, everyone. It's Jean Sachs, the CEO of Living Beyond Breast Cancer. Today, we are here to talk about a topic that I know is on everybody's mind, which is the FDA's recent recommendations of a third dose of the COVID-19 vaccine for people who are immunocompromised. We know this is an important question for our community, so I'm really pleased that we have Dr. Mehta, a medical oncologist and member of our board of directors who practices at MD Anderson Cancer Center at Cooper in Camden, as well as Holy Redeemer, outside of Philadelphia. Dr. Mehta is going to help us understand the questions and how we continue to live with uncertainties. So, thank you for being with us today.

Pallav Mehta, MD:

Thanks for having me, Jean.

Jean A. Sachs, MSS, MLSP:

Of course! Under the FDA recommendations, who in our breast cancer community would qualify for a third shot or a booster shot?

Pallav Mehta, MD:

As you know, about a week ago, this directive came out from the CDC that patients who are immunocompromised should get a booster. And over the last week, we've had several of the oncology societies and other organizations coming out with specifics on what that actually means, because I think for our breast cancer patients, immunocompromised can mean patients on chemotherapy, patients who are getting radiation, patients who are getting a targeted therapy. Who exactly fits that criterion actually to some extent will depend on your institution because each institution does have specific guidelines.

The CDC right now is leaving it somewhat general, but each institution [has its own specifications]. So, for example, at MD Anderson, our recommendations are looking at patients who are getting chemotherapy or have gotten chemotherapy within the past year. We're also including patients who had radiation.

Now, I can tell you, other institutions, Memorial Sloan Kettering, for example, another big cancer institution is looking at a 6-month timeframe and is not including patients who receive radiation. So, I think to some extent there will be some variation on the specific guidelines. I would certainly make sure patients check with their oncologist and with their institution. I would also make sure that they keep their eyes and ears open, because what I'm telling you today may not be exactly what we're saying 5 days from now.

Jean A. Sachs, MSS, MLSP:

Right. We're getting used to that, but this is still for people who are 8 months out from their original second shot? Is that still the timing?

Pallav Mehta, MD:

No. For patients who are immunocompromised, the actual recommendation is you have to have had your second dose at least 4 weeks ago. The 8-month window appears to be for — potentially, again, no one knows for sure what the next few weeks hold — but for folks who may fall under other categories in the non-immunocompromised. So, so at this point, if you've had a second dose, and it's been at least 4 weeks and you're immunocompromised, then you're eligible for the booster.

Jean A. Sachs, MSS, MLSP:

OK. So, you talk to your oncologist about that, or who qualifies you?

Pallav Mehta, MD:

At this point, I think the best person to talk to [is your medical oncologist], particularly because patients on immunosuppressive therapy are seeing their oncologist pretty regularly. And, for the most part, they're seeing their medical oncologist. So, really, just have a conversation with your medical oncologist. Just this week alone, I think, our center has received hundreds of calls on this. We've had very specific conversations with our triage nurses, our nurse practitioners, our infusion room team that often sees our patients, when they don't see us as oncologists. The institution should have a pretty coherent, consistent message, for the most part. So yeah, I would check with that team.

Jean A. Sachs, MSS, MLSP:

OK. And I'm, I've read that panic and the challenge that we had earlier in getting a vaccine should not happen this time, and that you'll have lots of places to go to.

Pallav Mehta, MD:

Right. I think that's the one real difference this time is that folks won't have to drive 3 hours to the middle of nowhere to get a shot. It is available. I think each pharmacy is also still looking at exactly how they plan on administering these logistics. Some will require a note from your oncologist; others apparently won't. But I think checking with the pharmacy, checking with the team — most centers are already looking at just some documentation, a prescription perhaps to give to patients for the shot, and some centers are actually offering the shot.

Jean A. Sachs, MSS, MLSP:

Got it. And if you received Pfizer, do you have to get the Pfizer for your third shot or Moderna? Or can you get whatever's available?

Pallav Mehta, MD:

The recommendation by all the societies at this point is that whatever you received is what you should receive. To be clear, Pfizer and Moderna are the ones at this point today, on August 20th, that are eligible for the third shot. So, the Johnson & Johnson, if you received that, today we're still not recommending a booster. But again, stay tuned on that.

Jean A. Sachs, MSS, MLSP:

OK. So, why do we need this third shot?

Pallav Mehta, MD:

Yeah, that's a good question. [We now can look at] the past 8 months of vaccination and 8 months of data on breakthrough cases. Most of us have seen this on the news and, and unfortunately a lot of us have seen this on our social media feeds — but when you look at breakthrough cases and vaccinated individuals, first of all, the risk of breakthrough cases, which primarily we're seeing in hospitalized patients [is very small]. The CDC initially tried to follow everyone with COVID. And what they realized is that there was this vast amount of under-reporting that was going on, for some people just because they were asymptomatic, but for others their symptoms were so minor that it wasn't being reported. So, ultimately around the end of April or so, the CDC changed how it's tracking breakthrough cases, only looking at hospitalized cases and of course, deaths from COVID.

And, currently, for a patient who has been vaccinated, the likelihood of them being hospitalized with COVID is about 0.004 percent. And then the risk of dying is a fraction of that. In other words, the likelihood is still incredibly low in vaccinated individuals, but when they looked at those, it was about 8,000 or so patients that were hospitalized of the 165 million that had been vaccinated. What they found is that immunocompromised patients actually made up a pretty large percentage of those patients. And for the last several months, even before vaccines, even as the vaccine was just coming out, there was data on what sort of immune response immunocompromised patients actually had to the vaccine. And what we found is for some, there was a diminished response.

We were measuring it; unfortunately, the only way we really could measure it is through these antibodies. But, you know, antibodies are the tip of the immunologic iceberg. And so immunity to vaccines depends on a lot of things other than just antibodies, but with antibody production, patients who had gotten chemotherapy, really their levels were a lot lower — transplant patients for example, were much lower. And so ultimately putting that all together and looking at hospitalized patients, it was determined that immunocompromised patients really do benefit. They also saw that from the first to the second dose, when you look at immunocompromised patients who develop antibodies, the first dose, it was a much lower amount, the second dose, they more than doubled their antibody response. So again, just kind of following that trend, the third dose would have increased production even more.

Jean A. Sachs, MSS, MLSP:

Wow. It really shows that you have to understand the data and not just believe the news headlines, I think. And we're getting this in real time. So, I think we all have to realize that we're learning. Just one other question, because we know many in the breast cancer community have kids under the age of 12, and that is putting an additional strain. So, what are your thoughts about when those children might have the opportunity to be vaccinated?

Pallav Mehta, MD:

I think, at this point we were hoping by the end of the summer, we would have something from the FDA. There is some data out there showing a significant benefit already with children under the age of 12. The, the important thing with younger children is that their likelihood, as we have seen now over the past year and a half, of getting really sick from COVID is a lot lower than it is for, say, a 70-year-old. And so when the FDA is looking at the risk benefit calculations, they have to take into account that the actual issue of COVID is less of an issue. The risk suddenly becomes a more important variable. And so we don't want children who otherwise may not have gotten ill anyway, to be exposed and potentially have a side effect that we haven't quite figured out so far, to be clear.

Pallav Mehta, MD:

It certainly looks like this is coming. We just don't have an exact date, because particularly as the delta variant has been the primary variant now that's emerged, we have to now look at that data in the context of some of the data that we have on the original variant, and how did that factor in. We've seen that children are making up a little higher percentage of hospitalized COVID patients than we had seen a year ago. So a lot of smart people are looking at all this on an hourly, daily basis.

Jean A. Sachs, MSS, MLSP

Right. OK. So, I think the message for those that are actively in treatment, in the breast cancer community, is that they should get their [third] dose, if they're more than 4 weeks out from their second dose. That's what you're telling your patients.

Pallav Mehta, MD:

Yeah. And I think that the message before that is get vaccinated. You know, I do have patients who, throughout this, have chosen not to for various reasons. And I think it's important to have a conversation with your team — if it's a few conversations, it’s understanding. No one wants to get sick, and no one wants to be hospitalized with COVID, and no one wants to die from COVID — particularly our patients, who already have gone through a life-threatening illness.

Sometimes I understand the concern people have because they've already gotten these treatments. And sometimes there's a concern that there's another substance entering their bodies. But remember, this is a well-tested vaccine. There's nothing new about it. This research has been going on for over a decade and it works; it works better than probably most of the vaccines we have. And it appears the risk benefit for the vast majority of people — it's worth it.

Jean A. Sachs, MSS, MLSP:

Right. Well, we agree with you, and I hope everyone gets their vaccines. Thank you so much, Dr. Mehta, and thank you to everyone who is watching and listening. Remember, visit lbbc.org for more information. If you need support, we have closed Facebook groups, so go to our website, and you can figure out how to join one of those groups as well as call our helpline. Thank you, and take care.