DEAR DR. ROACH: My sister is getting chemo for breast cancer, and her 4-year-old is due for his shots. She's worried that he won't be able to get them all because of her treatment. Our parents are unsure if they should go ahead and get the shingles vaccine since they are around her often. What are the guidelines on shots for close contacts of cancer patients? -- K.C.T.
ANSWER: It's much more dangerous for your sister to be exposed to a person with disease than a person who's recently been vaccinated, since the likelihood of a vaccine shedding from a vaccinated person to a person with cancer is very small. In general, your sister's child should get his scheduled vaccines.
Inactivated vaccines such as the flu shot, pneumonia vaccine and meningitis vaccines are always safe to use for caregivers of cancer patients, or those with immune system disease of other kinds. Live vaccines need to be looked at individually.
The measles, mumps and rubella vaccine is a live, attenuated vaccine. Fortunately, there has never been a case of disease transmitted to another person from the current MMR vaccine. A 4-year-old would normally get MMR, and her child should.
Varicella (chickenpox) is a live vaccine, and expert groups recommend giving the vaccine to family members. Transmission of the vaccine strain is rare, but if the child should develop a rash after the vaccine, he should not have close contact with the person with cancer until the rash is gone.
The oral polio vaccine should not be given, but the inactivated polio vaccine injection is safe. Only the safe IPV has been used in North America for decades.
The rotavirus vaccine is also live, but transmission to contacts has not been demonstrated, so expert groups recommend giving this vaccine as well to household contacts of people with cancer (rotavirus vaccine is normally given at 2, 4 and sometimes 6 months of age).
Of course, guidelines never take the place of specific advice given by a person's doctor, who knows their health condition.
I hope your sister does well with her chemotherapy. Dealing with breast cancer while being responsible for a small child must be an incredible challenge.
DEAR DR. ROACH: Several people have insisted to me that drinking carbonated soda, especially caffeinated soda, causes osteoporosis because it robs your bones of calcium. Is this actually true, and if so, where are the studies that show this? I have tried to research this online without success. -- P.L.P.
ANSWER: Two studies help answer this question. The first short study from 2005 showed that drinking carbonated water did not affect bone turnover.
The second, done by asking women their beverage choices and comparing them based on bone density, showed that women who drank cola, but not other carbonated beverages, had statistically significant lower bone density scores than women who did not drink cola, or did so less than once per month. This was true whether the cola was diet or decaffeinated. Men who drank cola did not have lower bone density than men who did not.
I am somewhat skeptical of these results. Why would there be a difference in women but not men? But then, I don't recommend drinking colas anyway. Carbonated water is generally fine, as long as it is without sugar; some quinine waters have sugar. However, the acidity can still damage the teeth.