The pandemic has continued to create a serious impact on many people especially those with comorbidities, including cancer patients, their families, and caregivers. With the confusion of whether vaccination is recommended for cancer patients and if it is, which is the safest one, is elaborately discussed in this article.

The COVID-19 pandemic continues more than 18 months after being first detected. This has impacted the management of patients with other illnesses as well. Cancer is one such disease in which the window of opportunity to cure is narrow. Hence, the goal of timely treatment needs to be balanced with the current COVID-19 scenario.

Most cancer patients are no longer thought to be at significantly increased risk of infection with COVID-19. However, if they do get it, the risk of severe infection and/or death is much higher. Hence, it is prudent to consider additional measures to protect patients with cancer.

One well-established strategy is to ensure that everyone is vaccinated against COVID-19 at the first available opportunity.

Is the COVID-19 vaccine safe for cancer patients?

For patients that have solid tumour malignancies (like breast or lung cancers), the general rule of thumb is that all of them should get the COVID-19 vaccine as soon as possible. Once the vaccination is completed and two weeks have passed (after the final dose), they will have good protection against COVID-19 and their level of risk should be similar to vaccinated normal (without cancer) individuals. Such a strategy will also allow the majority of such patients to continue their planned anti-cancer therapy as per schedule (without delay or reduction in dose intensity – continuing the schedule that is devised to provide optimal intended benefit). This should be the plan for solid tumour cancer patients planned for or undergoing cancer-directed systemic therapy (chemotherapy, hormonal therapy, corticosteroids, immunotherapy and/or personalised targeted therapy) surgery or radiotherapy.

There are certain exceptions or variations to this general rule based on special circumstances.

1. If the cancer treatment is to start two or more weeks later, the plan remains unchanged and the COVID-19 vaccines should be given on now priority basis.
2. If the patient is about to complete the cancer treatment in the immediate future, the COVID-19 vaccine should be given two weeks after recovery from the myelosuppression (if any) or two weeks after the end of therapy (if myelosuppression did not occur).
3. If cytotoxic chemotherapy is ongoing and will continue for more than two weeks, the timing of the COVID-19 vaccine should be in between chemotherapy injections, at a time when there is the least chance of having myelosuppression.
4. If there is the possibility to plan the COVID-19 vaccination date, it should not be on the same day as the administration of anti-cancer therapy. This is to avoid overlapping risk of side effects.

Haematological malignancies

The scenario is different for patients with haematological malignancies, for those receiving anti-B lymphocyte monoclonal antibodies (like rituximab) and for those undergoing hematopoietic stem cell transplantation. For patients requiring drugs that deplete lymphocytes (like rituximab, blinatumomab, anti-thymocyte globulin or alemtuzumab), the COVID-19 vaccine is recommended to be delayed up to six months after the end of therapy. The vaccine might be given earlier if lymphocytes have recovered earlier (ALC ≥1.0 and/or B cell counts ≥50 in peripheral blood). For hematopoietic transplant patients, the COVID-19 vaccine is also recommended to be given 6 months after recovery. If the vaccine is to be given earlier, recovery of the immune system should be verified (B lymphocytes >50; CD4+ T cells >100; no requirement of IVIG).

Which COVID vaccine should cancer patients receive?

Since none of the currently available COVID-19 vaccines is live (Covishield, Covaxin, Sputnik V), cancer patients can receive any brand of the vaccine available on the day they go for vaccination. Currently, available data shows that all these vaccines have similar efficacy in preventing serious infection, need for intensive care and death. The efficacy is also similar against commonly identified mutant variants of the COVID-19 virus.

COVID vaccine efficacy in cancer patients

The efficacy of the COVID-19 vaccine is well established in India, in real world circumstances too. Let us take the example of healthcare workers at CMC, Vellore (Victor PJ et al.). Of the 10600 staff, 8991 choose to be vaccinated and 7080 had received both doses. This represents a very high-risk population since healthcare workers are likely to be exposed to more infected individuals as well as those with high viral load. The protective effect two weeks after the completion of the vaccination schedule was very good. RT PCR positivity (infection without symptoms) was seen in 679/7080 (9.6%), need for hospitalisation was in 64/7080 (0.9%), need for oxygen therapy was in 4/7080 (0.06%), need for ICU admission in 2/7080 (0.03%) and no death in any of them.

While it is accepted that the efficacy of COVID-19 vaccines is less among patients with cancer, it is still sufficiently high to provide significant protection against serious/severe COVID-19 infection. The beneficial protective effect of the COVID-19 vaccination can be optimised by keeping in mind the following additional aspects:

1. Even if a cancer patient had got COVID-19 infection in the past, they should receive the vaccination. This should be given once they have recovered completely from the COVID-19 infection – negative RT-PCR test, no fever for at least 24 hours (without antipyretic medication) and resolution of all other COVID-19 associated signs and symptoms.
2. If the patient had received one dose and then got infected with COVID-19, the second dose is to be postponed till recovery from COVID-19. If this happens, and the second dose is delayed beyond the intended schedule, there is no need to repeat the first dose (no need to restart the vaccination schedule).
3. Vaccines should be given to cancer patients even if they have high levels of IgG antibodies following infection with COVID-19.
4. There is no need to test for antibody titre after vaccination. There is no evidence that the level of protection or immunity is related to such titres.

Disclaimer- The views and opinions expressed in this article are those of the author's and do not necessarily reflect the official policy or position of M3 India.

The author, Dr. Purvish Parikh is a Precision & Medical Oncologist from Mumbai.