Montefiore in the News
For High-Risk Cancer Patients, Experts Consider Any Vaccine-Induced Covid-19 Protection Beneficial
- March 9, 2021
Going through cancer treatment during a pandemic can be an anxiety-provoking process—from concerns over treatment delays to the risk of contracting the coronavirus. Add in the sense of isolation that comes while trying to avoid the virus, and the situation can become dire.
The growing availability of approved Covid-19 vaccines is providing hope that the pandemic will wane. But cancer patients have questions about their place in the vaccine line (which can vary considerably by location), as well as their ability to mount the immune response needed for vaccine-induced protection from future SARS-CoV-2 exposures.
After all, chemotherapy and other treatments used to beat back tumor cells can lead to a temporary dip in immune function, while other cancer treatments are designed to turn off immune "checkpoints" that otherwise stop the immune system from attacking some tumor cells.
"The goal of immunotherapy or checkpoint blockade is to actually stimulate the immune system. So there may be different effects on vaccine-induced immunity. Many of us are studying that to try to understand whether it's detrimental or perhaps even beneficial," explained John Wherry, director of the University of Pennsylvania's Institute of Immunology and chair of its systems pharmacology and translational therapeutics department.
In the meantime, though, Wherry and other experts say most cancer patients on treatment should get a Covid-19 shot as soon as it is available to them, since even lower-than-usual response to the vaccines is expected to offer protection.
"In general, the vast majority of patients with cancer — even those who are receiving treatment — should receive the vaccine and will benefit from it," Jia Luo, a fellow in medical oncology at Memorial Sloan Kettering Center, said in an e-mail. "Patients should speak to their oncologist about their specific case and the timing of their vaccination."
While Covid-19 vaccine efficacy needs further study in individuals on active treatment for cancer, ...
Though research is needed to tease out vaccine efficacy for individuals on active treatment for cancer (and those treatments can vary considerably by cancer type, subtype, and stage), the vaccines appear to be safe for cancer patients. And there is reason to believe they will offer much needed protection, even in individuals that have immune deficiencies due to treatment or cancer itself.
"The question is whether [Covid-19 vaccines] work as well in people having cancer treatment like chemotherapy and radiation," Luo noted. "A few cancer treatments reduce how well a person's immune system responds. It's possible that the vaccines might not be as effective in those people. Even so, having some protection is key."
Based on the data on hand and strong immune responses they induce, Wherry believes the available vaccines will likely offer some protection to immune compromised individuals by kicking both antibody-producing B cells and T immune cells into gear
B cells make secreted proteins—as antibodies—that interact with viral surface structures in a lock-and-key manner keep viral intruders out of our cells. But viruses that do manage to make it into the cell still have to contend with T cells, which take down infected cells that are starting to make copies of the virus.
T cells that have been primed by a vaccine are "ready to go," Wherry said, and "can eliminate that infection locally before it ever has a chance to spread and maybe before you know that you got a small infection."
Those strong immune responses can come with temporary side effects, he added, so a few days of feeling poorly is a normal response to the vaccine.
The immune landscape gets more complicated for cancer patients who have their antibody-producing B cells destroyed as part of the treatment process, including individuals with hematological malignancies such as leukemia or lymphoma that arise in those very cells, he explained. But there is a good change that vaccines can still boost Covid-19 immunity by readying T cells against SARS-CoV-2.
"If we need to now vaccinate you and we've just eliminated all of your B cells, we now have a problem that you're not going to generate antibodies as well," Wherry said. "The hope, in many of these cancer patients, is that we will be able to generate T cells that will provide at least some degree of protection from severe disease, even though they may not prevent initial infection."
Beyond benefits that vaccination can offer high-risk cancer patients and survivors, experts like Wherry noted that vaccinating individuals with reduced immune function might protect the broader community by preventing long-term infections implicated in the emergence of new SARS-CoV-2 mutations.
"There's not a large collection of data about this that allows us to think statistically, but there are a large number of anecdotes that have been reported about this. Most of the time when you see these prolonged infections, they're leukemia or lymphoma patients," Wherry explained. "When patients can't get immune control that leads to long virus replication with perhaps a very weak immune response, which is a perfect scenario to drive mutation and viral evolution."
At an online meeting on Covid-19 and cancer, organized by the AACR in February, oncologists and patient advocates participating in a vaccination-focused panel touched on such questions, as well as the burden being placed on unvaccinated cancer patients trying to avoid SARS-CoV-2. They also took stock of the grim outcomes that have been documented for cancer patients who contract Covid-19—the subject of countless studies over the past year.
For a retrospective analysis published in JAMA Oncology in December, for example, investigators at Case Western Reserve University considered health records for millions of individuals with or without cancer who were treated at US hospitals since 1999.
That study, which included data for more than 273,000 individuals diagnosed with cancer in the year leading up to August of 2020, suggested newly diagnosed cancer patients were more prone to contracting SARS-CoV-2 than people without cancer, though the risk varied with cancer type and patient ethnicity.
The Case Western team found that nearly 48 percent of adult or senior cancer patients who contracted Covid-19 landed up in hospital. In contrast, cancer-free people with Covid-19 were hospitalized just over 24 percent of the time and just over 12 percent of Covid-19-free adults and seniors were hospitalized.
Having both cancer and Covid-19 also increased the risk of death to nearly 15 percent, compared to a case fatality rate of around 4 percent in the cancer-only group and just over 5 percent in the Covid-19-only group.
Likewise, in a review article published in the journal Cancer Discovery last month, investigators with the AACR Covid-19 and Cancer Task Force estimated that the risk of death doubles in SARS-CoV-2-infected people with cancer compared to their cancer-free counterparts — findings that contributed to recommendations from AACR and other groups to prioritize Covid-19 vaccination in individuals with cancer and cancer survivors.
Covid-19 outcomes appear to be particularly poor in individuals being treated for hematological malignancies (leukemia, lymphoma, and the like) and people with thoracic malignancies such as lung cancer.
At the Montefiore Medical Center and Albert Einstein College of Medicine in the Bronx, investigators saw a case fatality rate of 25 percent for individuals with solid cancer types who contracted SARS-CoV-2 early on in the pandemic. That jumped to a 37 percent in the small group of people treated for hematologic malignancies during the same time frame, from mid-March to early April of 2020.
As the pandemic raged through New York City last spring, Luo and other investigators at Memorial Sloan Kettering found themselves poised to look at whether lung cancer treatments that target the immune system might make Covid-19 more severe and, if so, whether treatments should be delayed in these patients. That was not the case.
Though she and her colleagues found that patients with blood cancer and lung cancer were more likely to experience severe Covid-19, lung cancer treatment did not appear to impact that risk. In a subsequent analysis, the team spelled out some of the most important risk factors for individuals with lung cancer, including age, smoking history, and other chronic medical, Luo explained, which all increased severe Covid-19 risk more profoundly than cancer-related factors like lung cancer subtype, cancer stage, or treatment type.
"Based on our research, rather than delaying or withholding treatment, we advocated for focusing on safely treating lung cancer during the pandemic," Luo said.
"The most important thing to remember during this pandemic is that patients with cancer should continue treatment," she added. "Cancer care is essential care, and we don’t want our patients to put their life-saving treatments on hold."