Should a truth be suppressed because it will give people a reason to be cautious about getting the vaccine?
No.
I recall my wife got very ill because of the Covid vaccine. She got singles. I read the vaccine would suppress one's immune system which made a person more susceptible to other viruses. When I mentioned this to my boss at work he got upset and basically said I wasn't allowed to say that. Even though it was true as confirmed by her doctor and my own research.
But you are allowed to say that, just not at work perhaps.
And yes, you are correct about Covid shots activating shingles. There is evidence that repeated boosters, especially if given too close to one another and especially in the elderly and in those with preexisting conditions, can lead to enough immunosuppression to activate shingles, which is occasionally devastating:
Adverse effects of COVID-19 vaccines and measures to prevent them.
Shingles, as you know, is the result of a viral infection usually acquired decades earlier, and underscores the fact that some viruses make permanent homes in our bodies that can result in long-term sequelae. Besides shingles being long VZV (varicella-zoster virus) and that AIDS is long HIV (human immunodeficiency virus), which most people seem to know, cervical cancer is long HPV (papillomavirus), Multiple Sclerosis is long EBV (Epstein-Barr Virus), Alzheimer's is long HSV (herpes simplex virus), and liver cancer is long HCV (hepatitis C virus).
And we know that severe Covid infections produce irreversible organ damage, especially in the brain, lungs, heart, and kidney:
LUNG
New study into long-term impacts of lung damage after COVID-19 – UKRI
Study examines the effect of long COVID on lung health (medicalnewstoday.com)
KIDNEY
COVID-19 and Your Kidneys: What You Should Know
Long-term effects of Covid-19 on the kidney | QJM: An International Journal of Medicine | Oxford Academic (oup.com)
HEART
The COVID Heart—One Year After SARS-CoV-2 Infection, Patients Have an Array of Increased Cardiovascular Risks | Cardiology | JAMA | JAMA Network
COVID-19 (coronavirus): Long-term effects - Mayo Clinic
BRAIN
Severe COVID-19 can trigger drop in IQ similar to aging 20 years, study shows - UPI.com
COVID-19 and Your Brain: What You Should Know
It gets even more complicated. Immune suppression from past vaccines makes future vaccines less effective. And there is a vaccine for shingles.
As for myself, I'm almost 70 years old now, was vaccinated as soon as vaccines were available, and had my most recent booster last fall. We avoided the virus before vaccination, and perhaps since then as well, although we both had an unidentified upper respiratory track infection about six months ago which may have been Covid. We didn't feel the need to test, since we quarantined ourselves, which we would have done even for a simple cold, so we don't know.
My point is that if I've had that bug, I had it with a prepared immune system, which I assume minimized the viral load and the duration of the active phase of the illness, and thus the degree to which the virus penetrated and made a home in my tissues.
We need to assess the risk of being vaccinated compared to the risk of being unvaccinated. I will continue to take the risk of the vaccinating for Covid. But that might change in the future.