As we enter the third year of the COVID-19 pandemic, we continue to learn more about the respiratory virus leading to a better sense of prevention strategies. Our understanding of specific characteristics associated with a high risk of severe disease has grown, allowing more accurate identification of vulnerable individuals.
Inevitably, we quickly learned that cancer patients had a high risk of severe illness from COVID-19 infections. The National Cancer Institute (NCI) cautions that, in addition to cancer, older patients and those who are immunocompromised have a more significant risk of severe disease following COVID-19 infection. Because patients with blood cancers often experience abnormalities in the antibody-producing immune cells needed to combat viruses, these patients are at an even higher risk of severe disease or even death from COVID-19.
Vaccination against SARS-CoV2 is the benchmark to prevent severe symptoms, hospitalization, and death from COVID-19. However, cancer patients generate weaker antibody titers following vaccination than their healthy counterparts. While scientists actively investigate the precise relationship between cancer and COVID-19, we know that many factors contribute to the inferior vaccine efficacy among cancer patients.
A recent study in Annals of Oncology reports new information on COVID-19 vaccine efficacy in cancer patients. The study analyzed symptoms and outcomes in cancer patients who were unvaccinated and diagnosed with COVID-19 and those who were vaccinated against SARS-CoV2 and experiencing a breakthrough infection. The study did not assess the ability of COVID-19 vaccination to prevent disease.
The researchers defined vaccination as receiving two doses of the Moderna or Pfizer/BioNTech vaccine or one dose of the Johnson & Johnson vaccine. The study enrolled 54 cancer patients diagnosed with COVID-19 despite full vaccination. Of the fully vaccinated cancer patients experiencing breakthrough infection, 65% required hospitalization, and almost 20% entered an intensive care unit (ICU). Additionally, breakthrough infections contributed to death in 13% of the fully vaccinated patients. These risks associated with breakthrough infection were highest in patients with blood cancer.
The study concludes that cancer patients who develop breakthrough COVID-19 infections can experience severe symptoms and even death despite vaccination. The authors advise that COVID-19 vaccination remains an essential strategy to protect cancer patients. They suggest “a multilayered public health mitigation approach that includes vaccination of close contacts, boosters, social distancing, and mask-wearing should be continued for the foreseeable future.”
Many questions have emerged from the COVID-19 pandemic, and our comprehension of this disease is fast evolving, particularly when considering pre-existing conditions like cancer. Further, COVID-19 vaccine clinical trials excluded cancer survivors and patients immunosuppressed due to anti-cancer therapies like chemotherapy or radiation. Therefore, there remains a gap in our understanding of how COVID-19 and cancer impact one another. Notably, to learn more about the risk factors cancer patients face and assist doctors in treatment management for these highly vulnerable individuals, the NCI has commissioned a large-scale study of cancer patients who test positive for COVID-19. This study, called NCI COVID-19 in Cancer Patients Study (NCCAPS), is underway as researchers collect blood samples and medical information over two years following infection with or COVID-19.