DEAR DR. ROACH: I am a baby boomer who was born in 1949. I was vaccinated against polio as soon as it was available, and I was most likely exposed to measles and whooping cough. It was during the period when moms held get-togethers to expose their children in a semi-controlled way.

I volunteer with an organization that has many events for young children. Should I get vaccinations for these old diseases now that children aren’t being vaccinated for them? I don’t want to suffer from a childhood disease in my late 70s. — G.R.

ANSWER: People born before 1957 are so likely to have had measles, mumps and rubella (German measles) that they are assumed to be immune and do not need blood testing or booster shots, as these diseases usually provide lifelong immunity.

The virus that causes chicken pox stays dormant in the body, sometimes for decades, before reappearing as shingles. However, shingles does not occur as a result of exposure but because of a waning immune system due to stress, aging, or a medical condition or treatment for one. Everyone over 50 should get two doses of the shingles vaccine (unless they have a medical reason not to).

Polio fortunately doesn’t exist in the United States, but travelers to areas where polio is transmitted are recommended to get a booster before travel. Everyone should be up to date with pertussis (whooping cough), diphtheria and tetanus. A booster every 10 years is appropriate for those who completed the primary series.

There is no reason for measles or chicken pox (or any other vaccine-preventable disease) get-togethers anymore as vaccinations are much safer.

DEAR DT. ROACH: I am a 78-year-old woman who was recently hospitalized for a critical low sodium level (115 mEq/L). I was given IV fluids to bring my levels up slowly. I am now on sodium chloride tablets three times a day and a restriction of 1,000 mL of liquids per day to bring my sodium levels up. I have also been on metoprolol and lisinopril for a long time.

My question stems from talking with others and reading; I am wondering if one of these daily meds I am on are interfering with my sodium levels. — B.R.

ANSWER: It sounds like you were diagnosed with the syndrome of inappropriate antidiuretic hormone secretion (SIADH), which is a very common cause of low sodium levels. It is treated exactly the way you are being treated, with moderate restriction of fluid and supplemental sodium chloride (salt). They will want to keep your sodium level above 130 mEq/L.

There are drugs that can cause SIADH, especially antidepressants, seizure medicines, and antipsychotic drugs, but others can as well, such as many chemotherapeutic drugs for cancer and amiodarone. However, neither metoprolol nor lisinopril is likely to be affecting your sodium level.

Sometimes no cause for SIADH is found, but I’m sure that your doctors looked extensively for problems in your lung and brain, as these can cause the body to release too much ADH hormone. Addison’s disease (low production of cortisol from the adrenal gland) is another cause they will look for, usually with blood testing for cortisol.

It can be challenging to stick to only 1 liter of fluid intake a day. I have found several support groups online where members provide help to each other.

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.