How effective is the Shingrix shingles vaccine?

Q: My older brother suffered from long-lasting pain after shingles. This is something my late mother experienced as well. Consequently, I decided to go ahead and get the Shingrix vaccine.

For most people, it seems, the side effects of the vaccine are likely to be less troubling than the suffering resulting from shingles. My wife and I both had the vaccine. We had sore arms, with warmth at the injection site, but that was it. My brother is still receiving care at a pain-control clinic several years after having shingles. I would like to avoid that fate!

A: The Centers for Disease Control and Prevention estimate that the Shingrix vaccine is about 97 percent effective in people 50 to 69 years old. Effectiveness drops a bit in people over 70, to about 91 percent. That's still impressive.

Protection remains high for at least four years after vaccination.

Shingles is a painful rash caused by the virus that causes chickenpox. Sometimes after the rash fades, the patient is left with excruciating nerve pain and tenderness in that area of the skin.

That complication is called postherpetic neuralgia. It can be extremely hard to treat. Two doses of Shingrix were 91 percent effective in preventing the development of postherpetic neuralgia, the lasting pain your brother has suffered.

Shingrix is given as two shots two to six months apart. At the moment, the vaccine is in short supply, so many people who would like to receive it are having trouble finding it. Individuals who received the older shingles vaccine, Zostavax, at least five years ago can still benefit from the newer Shingrix vaccine.

Q: My 13-year-old son has attention deficit disorder. He has been on Actavis' generic Concerta OROS system with excellent results. He has made the honor roll and earned straight A's for four years running.

Last month the pharmacy switched to a different generic. He’s now failing math and is symptomatic. I know Actavis was purchased by TEVA. I contacted TEVA and was told Actavis 27 mg was on back order. No pharmacies in our region have any.

Do you know of an equivalent generic? Or could my son switch to regular methylphenidate tablets and take them breakfast, lunch and dinner? The extended-release version works so very well.

My son was in tears when he failed his first math test last week. He’s struggling to focus, and it is breaking my heart.

A: The osmotic-release oral system (OROS) was approved for Concerta in 2000 and allows for convenient once-daily dosing (CNS Drugs, November 2014). Actavis was selling this under an "authorized generic" agreement with Janssen, the original maker of Concerta. However, that agreement lapsed at the end of last year. Another generic supplier, Teva Pharmaceutical Industries, should be shipping authorized generic methylphenidate early in 2019.

Brand-name Concerta is available, though the cost could be around $350 a month. If that is unaffordable, you may have to discuss use of immediate-release methylphenidate with your son’s doctor. It sounds as though both you and your son are motivated enough for him to stick with a three-times daily dosing schedule. Three immediate-release pills a day should be as effective as one long-acting Concerta (Pediatrics, June 2001).