The COVID-19 pandemic introduced unique challenges for individuals undergoing chemotherapy. Chemotherapy treatments can significantly alter a patient’s immune system, making them more susceptible to infections like COVID-19. This article provides guidance for cancer patients and their caregivers navigating the complexities of chemotherapy alongside the ongoing presence of COVID-19. Understanding these dynamics is important for their well-being.
Understanding Vulnerability and Risks
Chemotherapy drugs suppress the bone marrow, leading to a reduction in white blood cells, including neutrophils and lymphocytes, which are crucial for fighting off infections. This compromised immunity increases the risk of contracting COVID-19 and can lead to more severe outcomes.
Patients with cancer are more likely to experience severe illness, hospitalization, intensive care, and a greater need for mechanical ventilation if infected with COVID-19. Studies indicate that cancer patients have a higher susceptibility to COVID-19 infection, with reported rates around 0.9% compared to 0.29% in the general population. Factors such as older age (60 years and above), a history of smoking, obesity, and other co-morbidities like heart disease, diabetes, and lung disease further increase the risk of severe COVID-19 in this group. Patients with hematologic malignancies, such as leukemia or multiple myeloma, particularly those who have received recent chemotherapy, face an even higher risk of severe infection and mortality.
How COVID-19 Affects Chemotherapy
A COVID-19 infection can directly and indirectly impact a patient’s chemotherapy schedule. Delays or interruptions in chemotherapy cycles may occur due to an active infection or exposure to the virus. For instance, guidelines suggest delaying chemotherapy for patients with mild to moderate COVID-19 symptoms until symptoms resolve, and at least 10 days have passed since symptom onset. For those with severely symptomatic COVID-19 or hematologic cancers, a delay of at least 20 days after symptom onset and symptom resolution is recommended.
Managing COVID-19 symptoms alongside the existing side effects of chemotherapy presents a significant challenge. Chemotherapy can cause nausea, fatigue, and diarrhea, which might overlap with or worsen COVID-19 symptoms. The decision to delay or modify treatment regimens depends on various factors, including the duration of viral shedding, the severity of COVID-19 symptoms, the type of cancer, and the risk of disease progression. Despite these challenges, there is currently no evidence suggesting that having COVID-19 will diminish the effectiveness of cancer treatment itself.
Vaccination Recommendations
Receiving COVID-19 vaccination is a recommended protective measure for chemotherapy patients. The Centers for Disease Control and Prevention (CDC), National Comprehensive Cancer Network (NCCN), and Memorial Sloan Kettering Cancer Center (MSK) advise cancer patients to stay current with their COVID-19 vaccinations. These vaccines, specifically mRNA vaccines like Pfizer-BioNTech and Moderna, and the Novavax protein subunit vaccine, do not contain live viruses and do not interact with DNA, making them safe for this immunocompromised population.
The timing of vaccination relative to chemotherapy cycles requires careful consideration and consultation with the oncology team. Recommendations often suggest delaying vaccination until two to three months after completing chemotherapy, or administering it between rounds for longer treatment plans. A waiting period of at least three months post-chemotherapy has been associated with a lower risk of infection and adverse clinical outcomes, particularly for patients with solid organ cancers. For individuals who have recently undergone a stem cell transplant or CAR T-cell therapy, a similar delay is generally advised, as vaccine efficacy can be reduced during periods of high immunosuppression. Updated vaccines are designed to target circulating variants and are recommended for everyone aged 6 months and older.
Prevention and Management Strategies
Implementing prevention strategies is important for chemotherapy patients to minimize their risk of COVID-19 infection. These measures include:
- Consistently wearing a well-fitted mask in indoor public places, on public transit, and in crowded environments.
- Practicing frequent and proper hand hygiene with soap and water or an alcohol-based hand sanitizer.
- Avoiding contact with individuals who are sick or suspected of having COVID-19.
- Regularly disinfecting high-touch surfaces in the home.
Should symptoms develop or a positive COVID-19 test result be received, immediate communication with the oncology team is essential. They will guide decisions regarding potential treatment delays and the management of COVID-19 symptoms alongside chemotherapy side effects. For high-risk patients, specific antiviral treatments such as nirmatrelvir with ritonavir (Paxlovid), molnupiravir (Lagevrio), and remdesivir (Veklury) may be considered by healthcare providers to help prevent severe illness. Remdesivir is often used for hospitalized patients, while oral drugs like molnupiravir and Paxlovid may be prescribed for outpatients to avoid hospitalization.