DEAR DR. ROACH: Please provide some clarity on family get-togethers in the new age of post vaccinations. Some members of our family have now been vaccinated, while others (mostly younger members in their 20s to 50s) have not yet – or may never be vaccinated, for reasons that confound me.

Our family would like to gather this year in a small group of about five or six people. May we all safely do so? Please note that I am immunocompromised after having received chemo for breast cancer. I am now fully vaccinated. My sense is that we may get together, although I should continue to wear my mask. What is your professional guidance? – E.S.F.

ANSWER: Recent interim guidelines released by the Centers for Disease Control and Prevention state that fully vaccinated people can visit with other fully vaccinated people indoors without wearing masks or physical distancing, and may visit with unvaccinated people from a single household who are at low risk for severe COVID-19 disease indoors, without wearing masks or physical distancing.

There are two concerns in your case: The first is that you may be at substantially higher risk, especially if your chemotherapy was recent. The second is that I don’t know whether the unvaccinated family members are really at low risk. The fact that they may choose against vaccination makes me concerned they also may not be following the recommended precautions to avoid getting infected. If you cannot be sure they are at low risk, I would recommend not getting together indoors or at least wearing your mask.

DEAR DR. ROACH: Is there an issue with getting the COVID-19 vaccine before a mammogram? – J.B.

ANSWER: The COVID-19 vaccine doesn’t increase the risk of breast cancer, but it does stimulate the immune system. The lymph nodes may become activated and enlarged after the COVID-19 vaccine. This can be mistaken for breast cancer on a mammogram.

About 8% to 16% of people getting the mRNA vaccines, such as the vaccine made by Moderna, will develop swollen lymph nodes that can be seen by a mammogram. Some women have chosen to reschedule their mammograms for four weeks after the final dose of vaccine. If you do get the mammogram shortly after vaccination, be sure to inform the radiologist so that can be considered when interpreting your mammogram. Please DO get your mammogram and not delay too long.

DEAR DR. ROACH: I am a 91-year-old woman with bullous pemphigoid, an autoimmune condition. I am very concerned about getting the COVID vaccine because of the possible side effects. I can find no information anywhere regarding this. Can you help me make this decision regarding the vaccine? – J.K.

ANSWER: Bullous pemphigoid is a potentially serious skin condition, which is indeed an autoimmune disease. The body reacts to a component of skin called the basement membrane.

COVID-19 vaccines specifically target the proteins of the SARS-CoV-2 virus. The concern that there might be a nonspecific increase in immune activity, including reactivation of targets of autoimmune disease, is theoretical, and there is not much support for it in the medical literature. Balanced against that theoretical risk is the very real benefit of protection against a disease that has killed over half a million Americans and millions more worldwide. At age 91, you are at very high risk from the virus, and to me the balance of risks and benefits is strongly on the side of getting the vaccine.

Dr. Roach regrets that he is unable to answer individual letters, but will incorporate them in the column whenever possible. Readers may email questions to ToYourGoodHealth@med.cornell.edu or send mail to 628 Virginia Dr., Orlando, FL 32803.