At the Leukemia & Lymphoma Society (LLS) we hear from patients with blood cancer every day about how COVID-19 affects every aspect of their lives, including critical decisions about their cancer care. This is of particular concern because patients with blood cancer who are infected with COVID-19 can have longer duration of infections, higher hospitalization rates, and higher mortality rates compared to patients with solid tumor cancer or individuals without cancer. Moreover, some blood cancer patients have prolonged infections that enable the emergence of COVID-19 variants.
Now that life-saving vaccines are available, we are hearing new concerns from cancer patients who are not feeling the same sense of relief as those without cancer: many wonder if the vaccines will protect them. As MedPage Today recently reported, they are right to be concerned.
In a U.K. study, patients who had solid or hematological cancer had a reduced ability to generate antibodies in response to the first dose of the Pfizer/BioNTech vaccine compared to healthy individuals. Only 13% of blood cancer patients produced significant amounts of antibody in response to the first dose compared to 95% of non-cancer patients. This finding is even more concerning in the U.K. where policymakers have delayed second doses in favor of using their limited vaccine supply to administer first doses to a larger percentage of the population. These data suggest that cancer patients may be more susceptible to COVID-19 infections after vaccination compared to the general public.
The U.S., in contrast, is sticking with recommended dosing intervals — 21 days for the Pfizer-BioNTech vaccine and 28 days for the Moderna vaccine. The good news from the U.K. study is that the second dose of vaccine partially restored the immune response in patients with solid cancers. But this study still lays bare something we suspected would be true — COVID-19 vaccines will not work as well in some cancer patients.
The study did not include enough patients with hematological cancers to draw conclusions about their immune response to two doses, but even if it did, blood cancer patients, and solid tumor patients for that matter, are not a homogeneous group. There are more than 100 types of blood cancer and a range of treatments with immune suppressive effects, including commonly used drugs like rituximab and BTK inhibitors for blood cancer that could place certain patients at a high risk of COVID-19 infections after vaccinations.
What we need is a wide-scale assessment of vaccine responses in all types of blood cancer patients at different points in their care. Since cancer patients were excluded from the trials used for FDA and EU authorization of the COVID-19 vaccines, we need to support efforts to get them into post-marketing trials. Fortunately, there are many large trials underway in the U.S. and the U.K. studying the response of patients with specific blood cancers to COVID-19 vaccinations.
LLS has also launched a research project through its National Patient Registry to gather real world data (NCT04794387). Nearly 2,500 current and former blood cancer patients have registered in the last month alone and recruitment is ongoing. Our researchers are gathering data to improve our understanding of how people with different blood cancers respond to COVID-19 and the vaccines so that vaccination strategies and timing can be tailored to maximize their protection. LLS is committed to sharing results with the medical and patient communities as soon as possible.
The sheer volume of patients who will be vaccinated in the coming months plus the ongoing risk of community transmission of the SAR-CoV-2 virus makes this a once-in-a-lifetime opportunity to gather vital information to learn about immune response in all types of cancer patients. But patients want and need answers today. Here is what we tell those who reach out to us:
- The vaccines are safe: there is no reason to believe COVID-19 vaccines are any less safe for cancer patients compared to the general population.
- Plan early: speak to your healthcare team as soon as possible to make a vaccination plan. For cancer patients on treatment, the question should not be if, but when to get vaccinated for the best protection.
- Encourage everyone in your household to get vaccinated: herd immunity can be viewed through even the small lens of a single household. If everyone around you is protected, you are much safer.
- Play it safe: continue good infection control practices recommended by the CDC. This is especially important for patients who may not get optimal protection from the vaccines. Until we can get the data necessary to determine which patients fall into this category, all blood cancer patients should continue wearing masks, social distancing, and handwashing.
While some cancer patients may be well protected from COVID-19 infections after vaccination, we have emerging data to indicate this will not be true for all cancer patients, and in particular, immunosuppressed blood cancer patients. It is vital that we encourage every cancer patient to discuss vaccines with their doctors. Every patient must be aware that any level of protection is better than none, two doses of the Pfizer-BioNTech and Moderna vaccines are better than one, and they should continue to follow infection prevention protocols.
Lee Greenberger, PhD, is chief scientific officer at the Leukemia & Lymphoma Society (LLS). He has over 25 years of experience in discovery and development of oncology drugs. He leads planning and strategy for LLS research programs.