DEAR DR. DONOHUE: Ten years ago, my then-3-year-old daughter received the chickenpox vaccine. I was thrilled when the vaccine came out because it meant that she and her younger sister would not suffer the way their two older siblings did when they had chickenpox. What I believed was lifelong immunity was not the case. She came down with chickenpox last week. My sisters believe this confirms that it is better to get the illness and “get it over with” when you are little. At this point, I have my doubts about the vaccine and am worried about my 10-year-old’s so-called immunity. Should my 10-year-old be revaccinated? – T.F.

ANSWER: Your sisters are dead wrong. Nothing has improved human life and prevented more illness than vaccines. In the United States in the days before chickenpox vaccine, around 4 million people – mostly children – caught the illness yearly. Around 100 died from chickenpox complications. Since the advent of the vaccine in 1995, few catch the illness.

The vaccine isn’t perfect. It protects about 80 percent of the vaccinated from getting chickenpox, and it prevents severe illness in 95 percent. That isn’t 100 percent, but it’s a lot better than it was before the vaccine was available, when epidemics swept through the country.

One out of every five vaccinated children can come down with what’s called breakthrough chickenpox. The illness is less extreme than it would have been without the shot, and it is less contagious.

Because of breakthrough chickenpox, the country’s immunization experts recommend a second dose of vaccine for those who have had only one dose.

Your 10-year-old should get another vaccine shot if she has had only one.

DEAR DR. DONOHUE: In October of last year, I had vertigo and a rapid heartbeat with dizziness, back-jaw-neck pain and headaches. An MRI indicated no problem. Several months later, with similar symptoms, I am diagnosed with what was first called premature atrial contractions but is now called paroxysmal atrial tachycardia. What is the difference between the two? My heart is sound, my blood pressure is normal, chest X-rays are fine and breathing tests are good. Could stress be involved? – C.I.

ANSWER: Premature atrial contractions are extra heartbeats that originate in the upper heart chambers, the atria. People with them often say their hearts skip a beat. They are almost never indicative of any heart disease.

Paroxysmal atrial tachycardia is a long run of fast heartbeats. Again, those beats originated in the atria. The heart speeds up to 200 or more beats a minute. The episode begins quickly and without warning – a paroxysm. People feel their hearts racing and they might become dizzy and short of breath. If such attacks last long or occur often, medicines can usually control them. Stress could trigger such episodes.

DEAR DR. DONOHUE: My youngest son had a toothache in a capped tooth. I am a canned-food hoarder. I gave him applesauce from a can that was a year old because it was soft and he could eat it without pain. He questioned if it was safe to eat. Everybody tells me that I should dispose of canned goods after one year. Should I? – M.M.

ANSWER: After one year, canned fruits and vegetables do not turn “bad,” but they start to lose some of their nutritional value. Some say canned goods are perfectly OK for five years. To be on the safe side, getting rid of them after one year errs on the side of safety.

READERS: Varicose vein problems are discussed in the booklet on that topic. It’s a subject that brings much mail and many questions. Readers can order a copy of the booklet by writing: Dr. Donohue – No. 108, Box 536475, Orlando, FL 32853-6475. Enclose a check or money order (no cash) for $4.75 U.S./$6.75 Can. with the recipient’s printed name and address. Please allow four weeks for delivery.

DEAR DR. DONOHUE: Does having legs of different length cause scoliosis?

I have scoliosis, and my doctor tells me that the curvature will progress 1 percent every year. Will wearing a lift for my shorter leg stop the progression? I am 74. – N.B.

ANSWER: Scoliosis is a curve of the backbone either to the right or the left. Most often it’s discovered in youth. The curve progression often slows later in life.

The amount of curve is determined through X-ray analysis of the spine and is given in degrees. In adults, curves less than 40 degrees rarely progress. If they do, they do so slowly. Curves greater than 40 degrees can progress by one degree each year.

Leg length discrepancy greater than half an inch (1.27 cm) influences the direction of the curve and can accelerate its advance. A shoe lift, therefore, might slow progression.

How great is your curve? Has it progressed in the past few years? If it isn’t a big curve and if it hasn’t increased in degrees in the past few years, it’s not likely to do so now.

Dr. Donohue regrets that he is unable to answer individual letters, but he will incorporate them in his column whenever possible. Readers may write him or request an order form of available health newsletters at P.O. Box 536475, Orlando, FL 32853-6475. Readers may also order health newsletters from www.rbmamall.com