Heated debate about antibody testing
Despite these reports of some patients with cancer having poorer responses, there’s some uncertainty over the benefit of giving a third (booster) shot.
There’s the question about the clinical relevance of antibody titer levels, and very little work has been done to date on cellular T-cell immunity from the vaccines.
“Right now, we are using titer levels like they actually mean something when they might not,” said Ravi Parikh, MD, a genitourinary and thoracic oncologist at the University of Pennsylvania, Philadelphia, who co-wrote an editorial that accompanies the Israeli report.
That’s one of the reasons why the FDA and others do not currently recommend antibody tests for COVID vaccine decisions outside of a clinical trial, but not everyone agrees with that position.
There’s been “a lot of heated debate in the medical community” over the issue, Dr. Haidar said.
The Icahn team, for instance, said that their results “underscore the need for routine serological monitoring of [multiple myeloma] patients following COVID-19 vaccination” to see if they might still need to mask-up and socially distance.
There is precedence, too, for vaccine boosters in cancer. As Dr. Parikh noted in his editorial, guidelines recommend revaccination after stem cell transplant for meningococcus, tetanus, and varicella, and other infections.
In France, COVID booster shots are already standard care for patients on dialysis and those on anti-CD20 agents, as well as for solid organ transplant recipients, for whom the literature supporting the benefit of COVID boosters is much more evolved than in cancer.
Israel has also authorized vaccine boosters for immunocompromised patients, including those with cancer, according to news reports.
It is also almost certain that the FDA will grant a formal approval for the COVID vaccines, at which point doctors will be free to administer boosters as they see fit.
“People are going to have to think really hard about what to do with them” if guidance hasn’t changed by then, Dr. Haidar said.
As the story unfolds, Dr. Haidar and others said in an interview that the take-home message for oncologists remains largely what it has been – namely to get patients vaccinated but also to consider masks and social distancing afterward for those at risk of a poor response.
Dr. Shah, Dr. Haidar, and Dr. Parikh have disclosed no relevant financial relationships. Dr. Parikh is a regular contributor to Medscape Oncology.
A version of this article first appeared on Medscape.com.