4/15/2021 4:59:29 PM
COVID VACCINES FOR CANCER PATIENTS; YES OR NO!?
The lockdown measures of the ongoing COVID‐19 pandemic have already disengaged patients with cancer from formal health care settings, leading to increased use of social media platforms to address unmet needs and expectations, which more often than not has caused the spread of unscientific ideas and deterioration of patients’ conditions. However, vaccines’ development has opened a window of hope and created a promising future in terms of controlling the pandemic and resuming back to normal life. Many countries around the globe have already been off to a great start, vaccinating many of their front-line health care workers and others highly at risk. Nevertheless, the main question in the field of oncology remains: Can cancer patients, as a priority group with a major underlying condition, be vaccinated?
Answering such a tricky question requires an interdisciplinary insight into various fields such as immunology, virology, cancer biology, pharmacology, and even psychology.
First, we should bear in mind that not all cancers are the same! In lung and breast cancer patients, for instance, studies have shown that the humoral immune response to influenza vaccination appears adequate. In another study of patients with various solid tumors, the response to vaccination was better than those of patients with lymphoma.
Second, many drugs have been known to cause adverse effects when administered simultaneously, and antineoplastic ones are no exception. Whenever possible, the administration of the vaccine should be performed before the initiation of chemotherapy in an attempt to prevent any sort of adverse drug reactions. In patients who have already initiated chemotherapy, the existing data do not support a specific timing of administration with respect to chemotherapy infusions.
Third, In order to generate protective immunity following vaccination, intact host immunity is needed, particularly with respect to antigen presentation, B- and T-cell activation. That’s why the NIH cancer institute has named a few contraindications in this context for patients who have just had a stem cell transplant or received CAR T-cell therapy, who are typically receiving immunosuppressive therapy. The NIH recommends that they postpone the COVID-19 vaccination until at least 3 months of theirtreatment completion. That’s based on the previous data of other vaccines indicating the limited vaccine efficacy during the time in which cancer patients are at their maximum immunosuppression.
So far, we‘ve learned that accumulated evidence from influenza vaccination suggests that patients with cancer are able to mount a protective immune response from anti-SARS-CoV-2 vaccines, though the level of immunity may be modulated by a range of factors (type of malignancy, antineoplastic therapies, and timing of administration, pre-existing immune dysfunction, fitness, etc.)
But is this all that science can provide us with???
NO! The story is not over yet as an underappreciated question regarding cancer-patients’ safety during the pandemic is whether or not their caregivers should be listed as a high-priority group? There’s no doubt that if you think about a vaccine’s strategy, assuming that people with cancer aren’t going to respond as well to the COVID-19 vaccine, one of the best ways to protect them is by vaccinating the people closest to them who will respond well. And that means anybody whom they spend time with. That will save us much time as it will decrease the caregiver’s risk of developing symptomatic infections and data suggest that symptomatic people are more likely to transmit the virus to people around them. Scientists also hope that available vaccines may prevent transmission—although available studies evaluating this question are ongoing. If that’s true, then caregivers getting vaccinated will really help. Because of that cocooning effect, vaccinating close contacts around people with cancer can provide extra protection.