Cancer patients, especially those who are undergoing the treatment in the form of surgery, chemotherapy, immunotherapy, targeted therapy, radiation therapy or any of the combination of the above have weak immune system. These cancer patients are at higher risk of contracting any type of infection including COVID 19. Many cancer patients and their caregivers are concerned about the upcoming vaccines as a protective measure against COVID 19 infection.
We are trying to provide general education to cancer patients and their caregivers about the aspects of COVID-19 vaccine especially in this category of patients. It is still time that COVID-19 vaccine becomes readily available. Before it becomes available, here are a few questions which as a cancer patient or a caregiver you would want answers to.
What are the types of COVID-19 vaccines available?
Multiple vaccines are under development for COIVD-19 at present. All of them can be broadly divided into these 4 types:
Inactivated or weakened virus vaccines: They use weakened virus, not capable of causing disease but can still generate immune response. Eg. Covaxin & Covishield vaccines
Protein based vaccines: These vaccines are made of small protein fragments which mimic SARS-CoV-2 virus & are capable of generating immune response.
Viral Vector Vaccine: These vaccines use genetically modified virus which are harmless but produce COVID-19 proteins capable to generating immune response.
RNA and DNA Vaccines: These use genetically engineered RNA and DNA which help produce protein further encouraging production of immune response. Eg. Pfizer-BioNtech & Moderna vaccines.
Which ones are available in India?
At present Drug Controller General of India (DGCI) has approved 2 types of vaccines in India, namely Covishield and Covaxin. Covishield is same which has been approved by UK government also. It has been developed by Oxford University along with AstraZeneca. In India, it has been produced by Serum Institute of India (SII). Covaxin has been developed by Bharat Biotech along with Indian Council of Medical Research (ICMR) and is in the final phase of its trial. Both of these vaccines are weakened and inactivated virus vaccines.
As a cancer patient should I get COVID Vaccine?
At present government plans to vaccinate front line workers as a priority. Cancer patients and survivors certainly constitute the high risk group and government plans to include people >50 years of age or those with co-morbidities as next group of people to be vaccinated.
Cancer patients are at higher risk of severe illness from the COVID-19 virus and should be vaccinated as more information regarding availability, efficacy and safety is available.
Will the COVID vaccine be effective in cancer patients?
The studies which evaluated the COVD-19 vaccine included only healthy adults and excluded cancer patients, those undergoing any form of chemotherapy or people with weak immune system. Also vaccines need a healthy immune system to produce immunity, and in those who are receiving chemotherapy the immune system is suppressed and an adequate response may not be evident. Thus it is not clear if these vaccines are equally efficacious in cancer patients.
Being a cancer patient, is it safe for me to undergo COVID vaccination?
In general, any cancer patient who is on chemotherapy or immunotherapy is asked to avoid any vaccine or is asked to consult with their Medical Oncologist before undertaking any vaccine. Same hold true for COVID-19 vaccine also. It is strongly advised that you consult your treating doctor before undertaking any vaccine including COVID-19 vaccine when it becomes available.
Both the vaccines available in India have been only tested in healthy adults and they have been found safe and given DGCI approval based on the study data.
Do I need vaccine if I was COVID positive in the past?
Yes, once the vaccines become available to the high risk group of people, you should vaccinate yourself irrespective of previous infection to provide yourself strong immunity against COVID-19. Also the safety and efficacy data would be more mature by then to take an educated decision.
Reference and further reading
Coronavirus disease (COVID-19): Vaccines
COVID-19 Vaccines in People with Cancer