Dear Doctor: I’ve had both doses of the Moderna vaccine, and my husband just got the Johnson & Johnson shot. Does this mean we can stop wearing masks? What does being vaccinated mean in terms of what we are safe to do now?

Dear Readers: With vaccinations taking place nationwide, we’ve entered a new stage of the pandemic. And just as when the coronavirus first began to spread throughout the world, we’re learning the answers to important questions about health, behavior and risk in real time.

You’ve asked one of the biggest questions we’re hearing lately, which is what fully vaccinated people can safely do. The fact is, until enough reliable data has been acquired and analyzed, we have only a broad picture of the do’s and don’ts of post-vaccine behavior. As time passes and we continue to learn and understand more, information about safe behaviors will continue to be fine-tuned.

When you get the vaccine, it takes two weeks after your final dose for immunity to kick in. Even then, though, you’re not home free. None of the three vaccines is 100% effective, which means that although the risk of infection and illness are greatly reduced, they have not been completely eliminated.

Another unknown is if people who have been vaccinated can still spread the virus. On that front, there’s encouraging news: Analysis of health data from 4,000 health care professionals, first responders and other front-line workers suggests that when people are fully inoculated, they are unlikely to spread the virus. To be certain, though, more research is needed. We’ll share updates as they become available.

To answer your question about what it is safe to do, the Centers for Disease Control and Prevention (CDC) has put together some general guidelines. The federal agency says that when out in public, everyone, including those who have been fully vaccinated, should continue to wear a mask and to practice social distancing. You should also continue to steer clear of crowded and poorly ventilated spaces. When it comes to private gatherings, the restrictions we’re familiar with have been somewhat relaxed.

Someone who has been fully vaccinated can attend small indoor gatherings with other vaccinated individuals without wearing a mask or staying 6 feet apart. The CDC says that these small groups may include unvaccinated individuals as long as they are from a single household and are not at high risk of severe COVID-19. “High risk” refers to someone who is 65 and older or has a health condition such heart disease, autoimmune disease, diabetes or cancer. It is recommended that you not gather indoors with unvaccinated individuals from multiple households. If a fully vaccinated individual comes into contact with someone who has COVID-19, they do not need to isolate or get tested, unless they develop symptoms.

When it comes to things like dining out, travel or going to the movies or a concert, we each have to do our own risk assessment. We know it’s been a long, hard year. But as you reenter the wider world, we urge you to be conservative in your choices, and err on the side of caution.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: My husband was recently diagnosed with Huntington’s chorea. Is this the same thing as Huntington’s disease? We would like to know what we can expect in the future with this condition. Are there any new treatments yet? What does this mean for our children?

Dear Reader: Yes, Huntington’s chorea and Huntington’s disease refer to the same condition. It’s a neurological disease in which ongoing damage to nerve cells in the brain leads to the steady deterioration of the individual’s motor skills, speech and memory. The changes that occur in the brain can also affect emotions, judgment and cognition.

Huntington’s disease is an inherited condition. It’s caused by a faulty gene that produces an abnormally long segment of a protein that is essential to brain function. These elongated segments get cut into smaller fragments that cluster together and accumulate on nerve cells in certain regions of the brain. This leads to a gradual and ongoing disruption of brain function.

Huntington’s is a progressive disease. Once the symptoms appear, they continue and worsen over time. In most cases, they become noticeable between the ages of 30 and 50 and typically begin gradually. Although their onset and progression can vary from person to person, they fall into three basic categories. Changes to movement can include increasing clumsiness; difficulty with posture, balance and gait, involuntary muscle spasms that result in jerky movement, abnormally slow eye movement, and difficulty with speaking or swallowing. Cognitive changes can include difficulty concentrating, increasing forgetfulness, memory lapses, and difficulty with logic and reasoning. The disease can also take a toll on an individual’s emotions and their personality. Some patients find that they begin to experience sudden mood swings, irritability or anger, frustration, anxiety and depression.

As the symptoms manifest and become more severe, the person eventually becomes unable to work or to manage the tasks of daily life. Someone with advanced disease will require full-time care. Because of the loss of motor function, people with advanced Huntington’s disease become susceptible to pneumonia, which is one of the primary causes of death in these patients.

Unfortunately, at this time there is no cure or treatment for the disease. Instead, a range of medications are used to manage the physical and emotional symptoms, as well as therapies to help the patient deal with them.

The children of someone who develops Huntington’s disease have a 50% chance of having inherited the mutated gene, and thus developing the condition. People with a history of the disease in their family can choose to meet with a genetic counselor to discuss whether they want to be tested for the presence of the mutation that causes the disease. It’s a difficult and deeply personal decision. Some children of Huntington’s patients choose not to know. Others, who plan to have families or want time to prepare should they test positive, decide to move forward.

For more information about all aspects of the disease, as well as support and advocacy, visit the Huntington Disease Society of America, at hdsa.org. It’s a very good resource for patients and their families.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: In fitness circles, one often hears the saying, “No pain, no gain.” But isn’t pain the body’s way of warning one to back off? Do you really need to push yourself to the point of pain for a good workout?

Dear Reader: You’re correct on both points. The idea of ”No pain, no gain,” which actually dates back to the second century, became widely accepted as an exercise mantra at the start of the 1980s. That’s when Jane Fonda’s exercise video empire brought aerobics to the masses. (People of a certain age may also remember “Feel the burn,” another popular phrase of the era.) And yes, the sensation of pain is part of the body’s alert system. It instantly lets us know that something, somewhere, is amiss.

Elite athletes and hardcore fitness enthusiasts may continue to adhere to the “No pain, no gain” way of training. However, when the goal isn’t breaking records or winning medals but rather the pursuit of good health, we think that a more moderate approach works best for the rest of us. When having this conversation with our own patients, we always refer to the part of the Hippocratic oath that states, “Do no harm.”

Note that when people talk about pain in relation to exercise, they’re actually referring to discomfort. It makes itself known in the burning sensation you feel in the muscles or lungs during exertion, and the fatigue that sets in when you push your limits. The burning occurs because your muscles’ need for oxygen exceeds the supply delivered in the blood; when that’s the case, they switch from aerobic to anaerobic activity, which doesn’t require oxygen. This leads to the formation of lactic acid, a byproduct of anaerobic respiration. The longer and harder you work while generating energy anaerobically, the greater the lactic acid buildup, and the greater the burn.

Discomfort might also mean the stiffness and aches in muscles and joints that many people experience a day or two after a particularly vigorous or sustained workout. The delayed soreness is the result of microscopic tears in the muscles and nearby connective tissues.

The gain part of that discomfort is two-fold. The accumulation of lactic acid plays a role in increased blood flow to the muscles, which helps with increased strength and endurance. Delayed soreness is believed to be a side effect of the healing process. It occurs as muscles repair themselves, and emerge stronger than before.

Outright pain should never be part of your exercise routine. If you ever feel a sensation that goes beyond discomfort and firmly into the realm of pain -- anything that’s sharp, stabbing or sudden -- it’s a sign that something’s wrong. Stop what you’re doing so you don’t cause more damage. The same goes for post-exercise soreness or pain that becomes extreme enough that you are unable to lift or use a limb. You need to stop that activity until you’ve fully recovered, or else risk injury.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)