Both my parents are about to receive the first shot of mRNA vaccine later this week (either from Pfizer or Moderna). They went through Covid-19 infection during the autumn the last year and have never fully recovered in a sense they have still been experiencing some lingering residual or new symptoms (hair loss, neurological disturbances, insomnia, etc.). The acute infection was harsh as well. I am a layman, so I have no idea whether the experimental vaccine could cause more harm to them in the long-term or not. What is your opinion on that?

Regarding non-vaccine related shingles, I experience a bout of them once in two years or so, it's always in summer and it's always related to heightened stress during summer (both the psychological and physiological - sunburns or sun tanning and a rapid temperature changes are a major trigger for me). I have extremely high levels of antibodies against various herpetic strains (ebv, cmv, etc.) and any form of prolonged stress, including poor sleep, causes the reactivation of the virus thanks to its hampering properties to immune system function. There are some really good information on this site: (https://acidicbody.com).