COVID vaccine safe even after previous chemotherapy

Dr. Keith Roach M.D.

DEAR DR. ROACH: I am over 60 and a teacher in California. I have some concerns about the COVID-19 vaccine. I was treated with Taxotere, Cytoxan and Herceptin back in 2006-07 for breast cancer. Is there anything about COVID or any of the potential vaccines that could impact me differently because of my health history, even after so much time has passed? -- R.I.T. 

      ANSWER: I see many questions about the COVID-19 vaccine. Unfortunately, we have no long-term data to guide us, so individual patients and physicians often need to do a personal risk assessment. That requires a thorough knowledge of a person's medical conditions. Your own doctor needs to go over your specific situation.

       Even though the body's immune system mostly recovers after cancer chemotherapy, there are often "holes" in the immune system, making a person more susceptible to certain infections. It is not possible to predict what infections these may be in any given person. Consequently, making sure you are up-to-date with all recommended vaccines is particularly important. You should also call your physician if you experience an infection. You are a bit more likely to have a more severe course.

       The currently available COVID-19 vaccines are not live vaccines and are considered safe for people with immune system problems. The only clear reasons not to vaccinate are a history of severe allergic reactions.

       My opinion is that with the information available now, it is more important that a person with a history of cancer chemotherapy receive the COVID-19 vaccine in addition to other vaccines, such as pneumonia and flu.

      DEAR DR. ROACH: I am 81 years old and in good health. I take no medications, but I am concerned about my GFR level. In 2018 my level dropped below normal at 58.5. In 2019 my level was 54.9, then 39.7, and back up to 58.5 six days later. In 2020 my level was 51.3. The level so far in 2021 is 50.1.

       The doctor says she will monitor the level and also doesn't know what caused the level to be 39.7 except to ask if I had taken Advil, which I had not. How concerning are my GFR levels, and is it normal for the GFR to fluctuate? Does the amount of water you drink help to improve the GFR level? -- J.

       ANSWER: All body functions fluctuate, to greater and lesser extents. The GFR is a measurement of the kidney function, and uses a measurement of creatinine, a muscle breakdown product, to estimate the kidney's filtering ability. A temporary increase in creatinine, from not having enough fluids, for example, can make the kidney function appear worse. Drinking more fluid than necessary does not help GFR, and can actually cause problems in older people by reducing the blood sodium level.

       If you plot your values on a chart, it makes it easier to ignore the fluctuations. It appears that you have had only a small decrease in GFR, as is expected. Kidney function does go down over time, but I think it unlikely you will have any problems for at least 10 years.