Cancer Patients and the COVID Vaccine
Source: Oncology Buddies
Dr Ria David educates us on the current recommendation for cancer patients getting the COVID vaccine:
Infection in the immunocompromised population, which includes cancer patients and those on chemotherapy, can lead to excessive morbidity and mortality. It’s therefore imperative, where possible, to protect these individuals against infection.
Immunisation against certain infections is an important and effective means of protecting cancer patients. This, however, needs to be balanced against the decreased potential for these individuals to mount an immune response compared to the unimpaired host. There is also concern over the risk of live vaccines (measles, mumps, rubella, zoster and varicella) causing vaccine-derived infections in some recipients.
The risk of infection in oncology patients depends on several factors, including the underlying malignancy and the type of immunosuppressive treatment the patient is receiving. Patients with haematological malignancies are generally accepted to have a higher risk compared to those with solid tumours. However, patients with solid tumours are also at risk due to chronic debility, malnutrition, advanced age, and comorbidities.
Numerous clinical trials are underway to assess the efficacy and safety of many COVID vaccines. There are currently four vaccines from Janssen, Moderna, Pfizer and AstraZeneca that are commercially available, although many more will soon come to market. Storage requirements and number of doses are different for each vaccine. Protection rates vary between different vaccines, ranging from 62% to over 90%.
Most importantly, vaccination is an effective means of preventing severe COVID infection and fatal complications of the disease. Despite concerns relating to reduced effectiveness against mutated forms of the virus, available clinical evidence reassures us that currently approved vaccines do offer protection against mutants.
A Favourable Risk / Benefit Ratio
Some of the unanswered questions regarding the COVID vaccine relate to the duration of protection, long-term safety, protection against mild versus severe infection, immunity in the elderly, the contagious potential of vaccinated individuals and repeat vaccination intervals.
Concerns have been raised about the risk of severe thrombosis and low platelet count in the first few weeks following vaccination. Healthcare professionals and patients need to be aware of the symptoms of these disorders. However, this risk is extremely low. It’s therefore held by most authorities that COVID vaccination carries a very favourable risk/benefit ratio.
The American Society of Clinical Oncology (ASCO) Recommendations:
- Patients with cancer may be offered the COVID vaccine provided there are no contraindications to any elements of the vaccine. Vaccine recipients should be counselled about the unknown safety profile in immunocompromised individuals, potential for reduced immune protection and importance of ongoing adherence to all guidelines to reduce infection.
- Patients receiving active oncology treatment may be offered COVID vaccination.
- Cancer survivors may be offered the COVID vaccine.
Only those individuals with contraindications to a specific vaccine component should not be vaccinated.
Regarding timing of vaccination, the National Comprehensive Cancer Network (NCCN) recommends that:
- Patients receiving haemopoietic cell transplantation should wait until three months after transplant.
- Patients on intensive chemotherapy regimens for acute leukaemias should wait until full neutrophil recovery.
- Patients undergoing major surgery should wait at least a few days before vaccination.
- All other oncology patients may be vaccinated when vaccines are available.
In the context of limited access to vaccines, the NCCN suggests that the following may be considered in the prioritisation of cancer patients:
- Prioritise those patients with active cancer on treatment, those planned to imminently start treatment and those immediately post treatment (< 6 months), except in those receiving hormonal therapy only (their risk is that of the general population).
- Consider other factors linked to poor COVID outcomes including, but not limited to, advanced age >65 years, comorbidities, social and demographic factors.
Ongoing surveillance in the context of clinical trials and post vaccine surveillance will generate data on vaccine safety and efficacy in the general population and special populations, including patients with active cancer and a history of cancer.
Dr Ria David is a medical oncologist and specialist physician with special interests in breast-, colorectal and haematological malignancies. She works at Oncocare at the Durban and Umhlanga offices and serves on the executive committees of the Durban Breast Cancer Forum and the Cardio-Oncology Society of Southern Africa.