FAQ now available on the third dose of COVID-19 vaccination in solid organ transplant recipients
On September 28, CDTRP held a special webinar with Dr. Dima Kabbani from the University of Alberta to discuss the latest research and what the transplant community should know about third doses. A Q & A has followed the presentation and you can find the transcript below.
Question/Answer with Dr. Dima Kabbani
Since morbidity and mortality are higher generally in those with comorbidities who have COVID-19, should adopting a healthy lifestyle be advised to help reduce the impact of comorbidities?
Some comorbidities can be modified with a healthy lifestyle, therefore this should be encouraged. However, if comorbidities already exist (for example chronic lung or kidney disease) unfortunately, lifestyle changes won’t do much at the point of COVID-19 infection. Therefore it makes solid organ transplant patients more vulnerable to the COVID-19 disease.
The data are trickling in for pediatrics. The PREVenT-COVID study (for more information on this please go to this link) is going to have a pediatric solid organ transplant group. What we know so far, is that the safety of the COVID-19 vaccine does not appear to be a problem. We were worried about seeing more side effects with possible pericarditis and myocarditis, which we have not seen and the immunogenicity data that we have is actually very good.
It all depends on what is happening where you live. In general, if everybody is vaccinated, then try to limit the numbers of people. But what we’re seeing in Alberta with a high level of circulating virus, we are encouraging our solid organ transplant patients to wear masks indoors.
What are the thoughts on the controlled temporary weaning of one or more immunosuppression drugs to increase the effectiveness of the COVID-19 vaccine in solid organ transplant recipients?
We worry that when reducing our immunosuppression medications, we’re going to see more rejection of the transplanted organ. I don’t think we should be encouraging our solid organ transplant recipients to decrease their immunosuppression so they would have more of a response to the COVID-19 vaccine.
For solid organ transplant recipients to be fully vaccinated against COVID-19, is it with two or three doses of the COVID-19 vaccine?
The terminology for the vaccine booster shot is an extra dose that applies for non-transplant recipients. To be considered fully vaccinated as a solid organ transplant recipient, it should be three COVID-19 vaccine doses.
What is your opinion on requiring COVID-19 vaccination for pre-transplant patients to be listed for transplant and if so, with two or three doses of the vaccine?
A lot of centers are looking into considering a requirement for pre-transplant vaccination. I believe the data are coming. We know that the immunogenicity of vaccines, if given pre-transplant, is much better than if it is given post-transplant. We know that the morbidity and mortality of solid organ transplant patients with SARS-CoV2 infection especially in the early period after transplant is high. Some centers have moved to mandating pre-transplant COVID-19 vaccination, but it is not the case everywhere. (Please check with your transplant centre on their COVID-19 vaccine requirements.)
Is there any news related to a COVID-19 vaccine booster shot for those who are solid organ transplant recipients?
There’s been just one small study that looked at this. The study showed an increase in antibody production. But the problem is that it’s not clear that continuing to give vaccine doses is going to be the answer. What about a fourth dose and a fifth dose of the vaccine? Most of these studies are just measuring antibody response. This is not the only response that we get with a vaccine. There is the T-cell immune response which we don’t measure when we just check an antibody response. So there are some patients that despite getting a third, fourth, or fifth dose of the COVID-19 vaccine, might still be at risk, lung transplant recipients, for example. In these patients, we need to think about other modalities, either to increase immunogenicity rather than continuing to give boosters, or consider another strategy to help reduce disease.
I have had my third COVID-19 vaccine dose. How do we know if we have enough antibodies that have developed to help protect me? Is there a test to verify the antibody levels or amount of protection?
We encourage patients not to get an antibody test. First, not all antibody tests that are available measure antibody response to the COVID-19 vaccine. Some of these antibody response tests just measure if you’ve been exposed to or infected with SARS-CoV-2. So that is a problem. The other thing is even in those that don’t have an antibody response, we have the T-cell immune response that we’re not measuring. The third thing, we don’t know what these numbers mean and at what level these numbers are protective against a COVID-19 infection. We know that the vaccines will protect solid organ transplant patients compared to being non-vaccinated and that there’s been a decrease in mortality. But breakthrough infections will still happen. That’s why I would continue to follow some of these protective measures like social distancing, mask wearing, and hand hygiene.
What about early COVID-19 infection intervention treatment options for solid organ transplant recipients? Is this an option that is available across Canada?
It’s an intervention available in Canada. We’re using more monoclonal antibodies (laboratory-made proteins that mimic the immune system’s ability to fight off harmful pathogens such as viruses) in those that are infected and still early in the infection. The big question is whether in those who don’t respond to the vaccine, whether these monoclonal antibodies could be given to try to prevent infection. Most of these monoclonal treatments are available in Canada through an IV. These are things we need to look more into going forward.
Yes, absolutely. We’ve seen much more severe disease in our lung transplant patients. In the PREVenT-COVID national research study (learn more here), we’re recruiting participants with different organ types and different immunosuppression regimens to address some of these questions.
What do we know about variants, the importance of Delta versus the South African variant and others?
I don’t know about specific data in solid organ transplant recipients. However, we know that the Delta COVID-19 variant is much more transmissible in general compared to other variants and can be associated with increased disease. I don’t think that we have enough data in our solid organ transplant recipients to comment on this. But I would expect it to behave the same way.
I would think so. When that’s going to happen, I don’t know. I think there are things such as more variants, vaccination locally and worldwide, and other factors that will play into this.
In Canada, would there be an impact on COVID-19 infections due to the changing temperatures during the winter and summer cycles?
I don’t know if it’s going to be related to a certain season. What we’re seeing is from activities that change from being indoors to being outdoors, is that COVID-19 is more transmissible when we’re inside. But I don’t know that if there would be a seasonal impact or not.
Without some type of antibody testing confirmation as a marker of protection, how can a solid organ transplant recipient who travels for work or pleasure have a sense of when those activities might be safely resumed? What marker or measure should one be watching?
It depends on when and where that person is travelling. I would still follow the precaution measures when travelling. I don’t know that the antibody test should be what makes us feel protected or unprotected because we don’t know what the numbers means and there are other types of immunity. It also depends on where we’re going, what’s happening with the COVID-19 variants, and it is more than just COVID-19 antibody levels.
What is the future test to determine protection against COVID-19? It's not clear right now, because even in healthy people we don't know what level of antibodies are associated with protection, right?
Correct. We need to understand what is more important in the protection against COVID-19.
How can a recipient feel safe around fully vaccinated family and friends when breakthrough infections are a possibility, especially if masks are not worn?
We know that non-immunocompromised vaccinated individuals are less likely to become symptomatic and transmit SARS-Co-V2. If you have your cocoon or bubble that is vaccinated, transplant recipients will have much more protection, even without masking at home on a daily basis.
About Dr. Dima Kabbani
Dr. Dima Kabbani is an Assistant Professor in the division of infectious diseases at the University of Alberta. Her clinical focus is infections in the immunocompromised host. She is the education lead for the transplant Infectious diseases fellowship program at the University of Alberta. Her research areas include the epidemiology and outcomes of infections in organ transplant recipients and more recently response to COVID-19 vaccines in organ transplant.