I have noticed some people have bad reactions to some foods. It may be an allergy or sensitivity or the inability to digest certain food properly.  I’m not sure how they find out, though.  She put herself on an extreme diet and it worked. You used process of elimination.

Many years ago I spent many hours sitting in a different type of allergy testing.The bottom line was thatmy absolute worst allergies were to candida and mold, both caused from antibiotics and steroids,prescription, of course. They were the ones that could put.me to sleep sitting upright in a wooden, straight backed kitchen chair. I would pull up my legs and curl up in a little ball. The tester would shout at me to open my mouth and I did so she could squirt something in it. Eventually, I got enough to a point where I would wake up and put my legs down.
My point of entry had been stomach, rear end, arms and eyes. I looked like a Peter Lorre monster around my eyes with one eye drooping so.much I got my drivers license photo postponed. One of the things the tester did was "muscle testing" to hone in on how severe my. infections were. She would then mix a drug for.me to inject myself with at home. That was the beginning. I was also tested for food and scent (ie laundry soap).
Many years ago there was a book about allergies being caused by candida. It was called "The Yeast SYNDROME", not Yeast Connection.

That is a severe allergy.

Very much so. Left me with arthritis in my hands in my 20's. It went away from the drugs but the quack who owned the clinic insisted I try hormones. Thought I would die and hands have hurt ever since.

That is too bad. It sounds like you have overcome a lot.

I have but on the other hand I feel I am healthier by avoiding the drugs that made me sick.

You are. You’re lucky you know what they are. I 

Easy. Easy. All antibiotics and hormones. I have not aged as quickly as friends taking them have.

It worked better than you thought it would.   Nice side effects from giving them up.

I would go with a qualfied "maybe", but generally it takes a lot longer than a few months to determine if the vaccine is truly effective, e.g. like the timetables involved to develop polio, measles, mumps, rubella, smallpox vaccines seems like the historical blink of an eye from our vantage point looking back more than a half century.

But when a pandemic is still devastating the economy, killing entire industries, etc., even a partially effective vaccine that, say, protects 90% of the recipients without causing adverse immunological reactions such as early onset fibromyalgia or similar things in a fraction of a percent of the population, is a good start.

Most people who are reasonably healthy and not immunocompromised would certainly benefit from even an early vaccine trial. But it needs to be followed up with any improvements, tweaks, etc. that turn out to be more effective in the future.

As a kid I was terrified of needles, but these days, I'd certainly roll the dice if the odds are pretty good. I got an MMR booster in late 2015 to early 2016 so it's probably time to get it done again anyway. They are saying that those who have an up to date MMR shot, while not even closely specific to Covid-19, may speed the immunological recognition of this new coronavirus just enough to reduce the severity of an infection just by getting ahead of it.

A friend of mine who does have severe allergies and autoimmune disorders said that normally she shouldn't be vaccinated due to the antigens designed to prime the immune system for the pathogen tends to cause sometimes severe and intense allergic reactions. But she said she'd take a good heavy dosage of Benadryl in advance, and make sure she was medically monitored for about a day or two with an IV drip already in place in case stronger steroids or other anti-inflammatory agents had to be administered in a hurry - as some of her reactions have sent her into anaphylaxis.

However - the buzzword is "herd immunity". Even an only 80 to 90 percent effective vaccine can break sufficient links in the person to person transmission chain - much like if *everyone* were to wear a mask in public - to keep one asymptomatic "super-spreader" from infecting a lot of people 2 or 3 degrees of separation apart from, say, some college kids' 21st birthday bash at a bar in Dallas infecting 14 family members, a couple of bartenders, waitresses, cooks, and dishwashers.

Then a more effective vaccine that gets into high volume production in, say, mid 2021, would make a secondary barrier and further improve herd immunity. <sarcasm> as long as we can go round up all the Jenny McCarthy anti-vax nut cases and go stick them in a special camp with infected people while they get sick and either recover or become disabled or die from it to teach them a lesson they'll never, ever forget </sarcasm>

But my friend with all the autoimmune disorders says that if the doctors think she's at too high of a risk of a severe adverse reaction to an experimental vaccine, that everyone else should absolutely get it who safely can, as the herd immunity can protect her and her parents, and some of her close friends also with autoimmune problems. Because those who suffer from such chronic problems tend to find one another in today's digital age and get more collective knowledge of their conditions than many specialist physicians could accumulate in an entire medical career.

Because while a doctor gets to go home at night and read journals after seeing patients and doing paperwork - lots and lots of paperwork since most patients are on SSI and Medicaid since their conditions have kept them out of the workforce, those who suffer with these diseases get to experience all of the symptoms, the side effects of medications, the beneficial effects (and lack of effect) of the same, on a 24/7 basis.

The other huge important thing with an effective vaccine is - disease doesn't care whether one is rich or poor, great or small. It's just that those who are stuck in a gig economy or have lost their health coverage when their employer went belly-up, need to be funded to get vaccines precisely because they are also part of the herd immunity.

I used to oppose universal health care vehelmently until about a decade ago. Now that I personally know people whose lives were saved thanks to the coming of Obamacare, and some who might be alive but unable to be productive at all, and thanks to subsidies and such can get the meds they need and regular checkups to stay functional and productive, I've kind of pivoted a 180 on that issue in the past few years.

And now with a Supreme Court challenge to possibly throwing the entire law out next year, and a LOT of people suddenly having to enroll in it as their lifeline - including many who never, ever thought it would happen to them - I find myself worrying about an issue that was traditionally on the far left. The thing that really changed my mind was working out the math and a few years of observation of actual results.

Seems that we are already spending at least as much propping up hospitals who write off tens of millions in bad debt from emergency room visits already. Texas ranks 50th out of 50 states in access to Medicaid, for example. The cutoff is about 10% of what it really costs to live on, so only SSI disability or complete homelessness living on skid row are the only ways to access it. So there are a vast number who fall through the cracks, and end up using the emergency room as their primary care physician.

Then of course they are absolutely judgment proof. They show up half dead in an advanced stage of an illness that would have been easily and cheaply (relatively) treated with early detection and intervention, they get stabilized, get a few meds and maybe some diagnostics, then are sent home to essentially either die or end up back in the E.R. when they can't afford to fill the follow-up prescription.

So it's like that Fram oil filter commercial. We could pay a little up front, or we can keep paying a whole lot later. And then of course there's the indigent burial expenses that usually follow the E.R. visit from some untreated condition that now is too far along to really do much, which is another huge hit to the taxpayers.

So yeah - I'd rather pay a little bit higher taxes and be sure that family that is living in their car surviving on little occasional odd gigs gets vaccinated, because that helps protect me and everyone else that might come into contact with them in the future. Same for those who are working but it takes about 98% of their total income for housing and utilities and some beans and rice, which in the post-pandemic world may become the new normal for a lot more people than we ever thought possible.