Although the basic message is simple—get the shot—the landscape of vaccination against COVID-19 has gotten increasingly complicated.
In recent months, the CDC has recommended a third, additional, dose for immunocompromised patients and booster doses (which may be third or fourth doses) for a variety of populations, based on age, health conditions, workplace, and which vaccine a patient received.
To help internists understand all the nuances, ACP Internist recently spoke with ACP President George M. Abraham, MD, MPH, MACP, who is an infectious disease subspecialist, chief of medicine at Saint Vincent Hospital, and a professor of medicine at the University of Massachusetts Medical School in Worcester, Mass.
Q: Could you explain the difference between an additional dose and a booster dose of the vaccines?
A: The CDC differentiates between a third dose and booster: People who are immunocompromised, who do not mount enough of an immune response to the first two doses, need a third dose to be able to get better immunity, while in people who have normal immunity, their immunity wanes over time, and so they need a booster dose. It's the same vaccine, being given at the same interval, for two different sets of people. The CDC differentiates [between the terms] to further highlight the fact that there are people who will require three doses to achieve almost full immunity, while others just need a booster because they have full immunity that gradually decreases over time.
Q: Is it necessary to explain the distinction between a booster and an additional dose to patients?
A: For the average patient, it probably makes no great difference whether we call it a booster or a third dose. I think it might be more important for physicians to understand who needs a third dose and who needs a booster. Probably from a layperson standpoint, it's semantics and doesn't need to be differentiated in any way. But I think for physicians to be able to answer questions better, it might be useful for us to at least know the difference and the rationale for the difference between the two.
Q: How does this distinction apply to the Johnson & Johnson (Janssen) vaccine, which was provided as one dose?
A: Given that we are at a stage where now the CDC has allowed what is called “mixing and matching,” which means you could get any version of any vaccine in any sequence, it probably is less of an issue. Rather than the J&J recipients getting a second dose two months after the first dose, as the company seems to recommend from its own studies, there seems to be fairly robust science to suggest that [with a booster of] an alternative vaccine, such as the Pfizer-BioNTech or Moderna vaccine, there might be a better response in people who have taken the first dose of the J&J vaccine.
Q: What are your thoughts generally on physicians advising patients or deciding themselves about whether to mix and match?
A: First, we know it's safe. There was a lot of data from Europe and other parts of the world that started doing this much before we did. The NIH study [published as a preprint in October] seemed to confirm the fact that it's perfectly safe to mix and match, which is what we suspected all along, but we have science to back us up now. With that said, the question is, do we need to mix and match? Is there some benefit by mixing and matching between even the two mRNA vaccines? It seems that they're pretty comparable. So the CDC's current position is you could continue to get your booster with the same vaccine that you got your original series from, but if for any reason—availability, convenience, preference, other reasons—you might want to mix and match, it's perfectly safe to do so. We should be able to generate enough of an immune response without any increase in risk of adverse effects.
Q: How deeply do internists need to delve into all these topics with their patients?
A: I think the short answer is it might vary depending on who our patient is. There might be some patients who might choose or want to know more information, and to those people, giving more information might help them become more informed consumers, so to speak. But there might be others who might just lean on their physician to give them a directive, essentially, tell them what might be the best step for them. Either way is fine. I think it's individualizing the amount of information we want to give, depending on who the patient is and how receptive they are to the information, how eager they are to know all the details.
Q: Is there any other advice you'd give internists on having these conversations with patients?
A: I think the biggest challenge for all of us as internists is addressing issues of vaccine hesitancy and counteracting the immense amount of misinformation and disinformation that's out there in social media, websites, radio, talk shows, or television, etc. Just continue to remind our patients that more than 6.5 billion doses of vaccine have been given worldwide, and that it's extremely safe, and that this is the only way we could bring our pandemic under control.
We want to return to as near normal as we can, and to do that requires a collective effort. Addressing some of those misgivings would be time well spent. We are successful on some occasions, we are unsuccessful on others, I will readily admit. But we keep trying. Sometimes it may take more than one occasion to convince someone. Every person who [gets vaccinated] will be one additional person who we would have kept safe and helped to keep our community safe.