Oh, I’m sorry, I missed this bit with the dates!

That explains everything.
Your wife showed symptoms
17 days after vaccination. In that case, the symptoms had nothing to do with the vax; it sounds like your wife became infected with SARS-CoV-2 and developed a mild and quick case of COVID-19, as
exchemist said in post #12……
It should be noted that the various vaccines available were approved on the basis of their ability to prevent serious COVID-19 symptoms,
NOT their ability to prevent SARS-CoV-2 infection. Having said that, growing indications are that they are also very good at preventing infection in the first place (potentially up to 80-90% protection), which is a really good outcome. So, your wife was unlucky, but the vax may well have prevented her from developing a worse case of COVID-19. Well played Kumar!
I notice that your wife’s PCR results had a Ct value of 19. That is a low Ct value for the RT-PCR test and indicates a very high viral load in her sample, indicative of the first few days after infection. So, it looks like she contracted the virus on, or about, the 27th and had a quick incubation period. Incubation periods before showing symptoms (if any) is usually longer than that (up to 2 weeks), but can be as quick as 1 or 2 days.