Dear Dr. Roach: I read your column every day and have seen many questions about the Shingrix vaccine. I have a question that hasn’t been addressed. In 1991, at age 29, I was part of the Merck Varicella vaccine study at Columbia University in New York City. To qualify for the study, I went through extensive testing, and it was confirmed that I’d never had chickenpox. I received two doses of the vaccine during the trials, and they followed my titer levels for many years. As of 2007, I still had titers. The vaccine I received was the one that ended up being approved by the FDA and is currently in use. I am getting conflicting opinions from my doctors about whether I need the Shingrix vaccine. My internist recently said, “Since you never had the chickenpox and actually received the chickenpox vaccine (Varivax), Shingrix would not be recommended for you.” What is your opinion?
Yours is indeed an unusual situation. The vast majority (more than 99%) of adults have had chickenpox, even those who have no clinical history. Especially at young ages, chickenpox may not have the typical rash that allows a pediatrician or family doctor to make the diagnosis. As such, the Centers for Disease Control and Prevention recommends that adults over 50 get the new Shingrix vaccine without doing any testing, even in people with no known history of chickenpox.
For those few people with absence of proof of infection of chickenpox, the recommendation is to give the chickenpox vaccine, and then the Shingrix vaccine. Thus, I disagree with your internist. The chickenpox vaccine is not effective enough to reduce your risk of developing shingles, and Shingrix dramatically does so.
Put another way, consider the downside: Two doses of the Shingrix vaccine normally causes only mild side effects, such as sore arm, a little bit of fever and feeling lousy for a day or two. Balanced against that is the expected 97% reduction in the risk of developing shingles. Shingles is much worse than the side effects of the vaccine and can sometimes cause devastating complications, especially post-herpetic neuralgia, which is persistent burning pain that can continue for months or even years.
Dear Dr. Roach: I have seen a couple videos and read a little about ivermectin use with COVID-19 and wondered what your thoughts were.
Ivermectin is a prescription drug that is approved by the Food and Drug Administration for the treatment of certain parasitic worms in humans. It is also used in veterinary medicine. A preliminary study showed that ivermectin can inhibit replication of cells infected with SARS-CoV-2, the virus which causes COVID-19. Several studies have since been done, and although some have shown promising results, it is still too early to recommend treatment. For one thing, the dose needed to inhibit viral replication in test tubes was not possible to achieve with treatment in humans. Moreover, there are many examples of promising candidate drugs that have failed when subjected to rigorous trials. These types of trials are ongoing now. Until the results are available, I would recommend against the use of ivermectin. Let me implore people not to treat themselves with veterinary ivermectin. These products are not designed for humans.
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