Commander J.H. Furman is claiming that Covid vaccines, not Covid, are a "national security threat". He's bought the anti-Covid-vax pig manure.
"Long-term" is a vague term, intentionally so when anti-Covid-vaxxers use it. The most serious side effect for DES did not become known until 2 or 3 decades after it was approved for use. What is known are the side effects up to ~17 months after being vaccinated with Moderna or ~16 months after being vaccinated with Pfizer (Moderna started testing in March 2020, and BioNTech in April 2020).
What is the largest USN ship a Commander would command? A DDG? An SSN or SSBN? A minesweeper?