Steven Pergam, MD, MPH, director of infection prevention at Seattle Cancer Care Alliance and infectious disease physician at Fred Hutchinson Cancer Research Center, discusses delayed booster vaccines and potential fourth doses for people who are immunosuppressed.
The new normal for COVID-19 vaccination may be 3 doses for the general public and 4 doses for people who are immunosuppressed, said Steven Pergam, MD, MPH, director of infection prevention at Seattle Cancer Care Alliance and infectious disease physician at Fred Hutchinson Cancer Research Center.
Some patients with cancer began receiving boosters as early as 8 months ago. What do the data tell us about the importance of the third shot?
It actually is interesting. Now we're even talking about fourth shots because, in someone who is newly getting vaccinated series, this is a nuance that sometimes is missed. There is this period where people were getting 2 shots for a primary series. In the midst of that, there was an additional booster that was added but, at the same time, anyone who's starting a new series would get 3 as their initial series, and those who got 2 as the initial series then got a booster. At 6 months post, you get a booster, and then in an additional 6 months people are actually available for another booster. Recent updates from the CDC today was actually moving the booster maybe even a little forward to 5 months for certain individuals.
What is interesting about the way the boosters work, at least within the general public—I haven't seen as much data in the cancer population yet, but I'm sure that it's going to be similar—is that, that first booster—I don't like using the first booster anymore, it's confusing, I like to use third dose versus booster being the fourth dose if you really think about this—people who got that third dose, that immune response is higher than the response you got after the second dose. We found that delay [in receiving a] booster, you get a higher antibody response than you ever received after that second dose. It could be anywhere from 8 to 10 times higher in the general population, which is important because, for some of these variants, that level of antibody seems to be important in terms of protection. For immunosuppressed patients, if you can get that antibody level up or at least improve the immune response, then that might potentially help people from getting not only infected, but really the important things are going to the hospital or dying from the disease.
So the booster does appear to have an effect, and that late boost may be part of the advantage. Actually seen in AstraZeneca—which is an adenovirus vaccine—is they found that if they move the booster out a little further, they found they had better immune responses in some of their initial studies. We've seen this sort of approach with other vaccines, where you get a 2-course series early and then you get a late booster as a way to sort of re-educate the immune system, that really helps to boost the immune responses. I think, in some ways, this really is a 3-dose vaccine for the general public and really a 4-dose vaccine for the immunosuppressed population, is really what it looks like.
What advice do you have to protect patients with cancer and other populations from COVID-19?
One is that the other place we need to spend a lot of time is vaccinating cancer patients' family members and making sure that all those around them are vaccinated. One of the easiest ways to get infected is to have people in your household that are infected. If you can protect yourself and get your family members and those close to you vaccinated, that's a great way to protect you even if your response to the vaccine is not as good. Two is that there are a lot of simple things that people can do to protect themselves beyond vaccination. I think it's really important to be masking in public, avoiding crowded places, really trying to decrease the size of the bubble that you spend time with, and if that is a bubble, make sure that that group is vaccinated. Be talking to your providers and telling them if you have any symptoms, whether it's a runny nose, a headache, sore throat, because being determined that you have COVID early is critical so we can give you some of those newer therapies that are out there, like the drug paxlovid, or the newer monoclonal called sotrovimab. Those are becoming more available and cancer patients are eligible to receive some of those and so we want to get them out to patients as quickly as possible even if they are vaccinated.