DEAR DR. ROACH: I belong to a garden club that meets in a local indoor hall. We have one member who has been driving herself crazy worrying about COVID-19. She wants us to meet outdoors even in the winter, because she says we can’t be sure the building is clean enough and we don’t know the status of others who may have used the building while we are not there. The hall employs a cleaning person who, to all appearances, does a good job. As long as our members are all vaccinated and wear masks (they are and they do), what else do we need to do to be safe? How would you reassure this member and any others who are concerned? — L.C.

ANSWER: The main risk to you and your fellow garden club members does not come from the hall. The risk from acquiring the virus that causes COVID-19 from surfaces is low, although it is certainly possible. Cleaning the surface drives this already low risk to near zero.

The main risk remains person-to-person transmission through respiratory droplets. Masks dramatically reduce the risk of transmission, and vaccines greatly reduce the risk of getting sick from COVID-19.

Since I can’t guarantee that there is no risk of infection, a person always needs to balance the risks of infection against the benefit of getting out and meeting your friends and doing your garden club activities. An individual’s medical condition (such as immunosuppression), whether they are a caretaker for someone, and the prevalence in the community all impact the decision. All that being said, it seems that based on 100% vaccination and mask wearing, the risk to your garden club members is small.

DEAR DR. ROACH: I am 58 years old and had a severe case of chickenpox when I was in grade school. I noticed that the shingles vaccine now has a warning about Guillain-Barre syndrome. How safe is the shingles vaccine? Are there other versions of the vaccine that don’t have that warning? — R.H.

ANSWER: Guillain-Barre syndrome is a condition causing damage to the nerves. It is usually triggered by an infection, but has been in rare cases associated with some vaccines. Most people recover fully from GBS, but in some people there can be permanent nerve damage.

After the new two-shot shingles vaccine (Shingrix) was approved, post-marketing studies noted a small increase in the risk of GBS after the first dose of the vaccine. The estimated risk is approximately 3-6 people per million in people over 65.

The shingles vaccine was 97% effective at preventing shingles in people over 50, although it is a bit less effective (90%) in people over 70. In my opinion, and in that of the Food and Drug Administration, the benefits of the vaccine outweigh the risks. The shingles vaccine is very safe, but no vaccine, like no drug, supplement or herbal medicine, is 100% safe.

DR. ROACH WRITES: A recent column regarding a doctor who appeared to be impaired while performing a colonoscopy generated several responses from readers. One suggested the doctor recommended a virtual colonography, which uses CT technology. Another thought there might have been a blockage requiring immediate evaluation by a CT scan. I maintain my original recommendation, that an investigation is called for. Only strong evidence would lead to actions against the physician.

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.