Q: When I searched the internet to see if COVID vaccines by chance made warts go away, I found your article. I had a wart at the base of my left index finger for 15 or 20 years. I got the Pfizer vaccine in February and March 2021 and the booster in October. I just noticed, in January 2022, the wart is completely gone. Could the COVID vaccine be responsible?

A: We have heard from quite a few readers that they too had warts disappear following COVID-19 vaccination. Your question prompted us to search the medical literature for similar reports. We found two cases (Transplant Infectious Disease, August 2021; Journal of the European Academy of Dermatology and Venereology, Oct. 26, 2021). One patient had a “15-year history of treatment-resistant warts that regressed during COVID-19 (Coronavirus disease 2019) treatment.” The other was a young woman who’d had warts on her thumb for two years. They disappeared after she got vaccinated.

Dermatologists have been experimenting with injections of other types of vaccines (measles-mumps-rubella, known as MMR) directly into hard-to-treat warts (Journal of Cosmetic Dermatology, Jan. 8, 2022). The success rate has been significant. This suggests that vaccines can stimulate an immune response against the viruses that cause warts.

Q: I have read that zinc lozenges are good against colds, especially if used together with vitamin C and quercetin. Is there any proof that this combination would be beneficial for the immune system?

A: There are data supporting the benefits of both zinc and vitamin C against upper respiratory tract infections, aka colds (European Journal of Clinical Nutrition, April 2017).

Quercetin has not been well studied for fighting infections. One study did not show a difference in rates of illness or symptoms (Pharmacological Research, September 2010). On the other hand, a study conducted in China showed that quercetin has activity against influenza viruses in cell culture (Viruses, January 2016).

We will need to see large, well-controlled clinical trials to learn whether this natural product can improve immune response and shorten the duration of colds.

Q: I read that taking drugs like simvastatin can reduce my levels of CoQ10. What is that? Do I need it? Can I supplement it with something in my diet?

A: Your body makes Coenzyme Q10 (CoQ10). In particular, this natural substance is essential for the proper functioning of mitochondria, the power factories of every cell in the body.

Statins interfere with the production of CoQ10. This has led many doctors to speculate that depletion of this compound might be responsible for statin-associated myalgia (SAM). It is characterized by muscle pain, weakness and cramps. Sadly, though, studies have not demonstrated that supplements of CoQ10 can counteract this complication of statins (American Journal of Health System Pharmacy, June 1, 2017). CoQ10 does appear safe, except for people taking the anticoagulant warfarin.

This supplement has been shown to be helpful for people with heart failure (Cardiology Journal, March 5, 2019). CoQ10 is available in the diet. The foods that supply the most are meat, fish and poultry, but oils from soybeans, corn and olives also provide it, as do seeds and nuts.

In their column, Joe and Teresa Graedon answer letters from readers. Send questions to them via www.peoplespharmacy.com