During a few of the years that I administered vaccines while working as a home health nurse, not a single patient had a side effect from any of the vaccines, other than a mildly sore arm for a few days.
Yeah? I got a shingles vaccination yesterday and my arm feels like it might fall off.
Yeah, Shingles and Covid are prone to provking sore arms.
I inadvertently found an answer for Covid: take a hike. If the terrain isn't flat I need poles or I'll hurt my knees. And that's excellent for the move-your-arm advice. I completely forgot about it until I rolled onto the spot at night--there had been absolutely zero soreness because hiking had made me move my arms enough.
My husband and I had our latest COVID booster two days ago and our arms were only mildly sore. But, then again, the perception of pain varies greatly from person to person. Perhaps my chronic pain issues, which are often severe make it seem like the reaction to a vaccine was very mild. I do think I had a rather bad headache after one of my shingles vaccines that lasted for several hours. It's been over a year but I don't recall having a very sore arm from that vaccine. Regardless, a sore arm is a small price to pay for a vaccine that prevents or limits a case of a virus to something very mild or asymptomatic. I had Covid once with very mild symptoms that lasted less than two days. Vaccines are often life savers.
I did ask the person who injected us if she had heard of any way to lesson the soreness or if the soreness was less if the injection was given in the dominant arm. She laughed and said she had never heard of that, so who knows. I went ahead and had the vaccine in my less dominant are again. Two days later, the soreness is gone.
Let me add that I've read there is some evidence that autism is more common when a father is older. Fresh sperm, with old equipment.

The jury is still out on all of the causes, but autism has nothing to do with vaccines. Plus, it's likely that milder cases of autism were never even diagnosed in previous decades. I think in retrospect that a classmate of mine in grammar school likely had some mild form of autism, but we all thought, despite liking the kid, that he was just a little bit weird. Nothing wrong with that. Being different is better than being like everyone else, imo. The only person I knew who was extremely autistic and totally dependent on others, had a mother who used many strong, dangerous recreational drugs when she was pregnant. That is likely another cause.
As far as obesity goes, there are lots of reasons for it. Some of it is genetic. My two sisters were very obese, likely inherited a trait from our late grandmother. But, they both ate a tremendous amount too. One had weight loss surgery and kept the weight off. The other one died of kidney cancer. Obesity is a huge risk factor for that and for years, she weighed over 300 lbs. I've never been obese and am now smaller than ever. I am a lot like my late mother and we both started becoming more active and thinner when we reached fifty. We were both slightly overweight, freaked out and then lost the weight. Genetic influences are interesting. There are also medications that can cause obesity. For example those who have to take steroids on a regular basis often suffer from obesity.
Imo, a lot of obesity is probably related to eating in restaurants on a regular basis, like so many Americans do these days. If you look at the caloric content of most restaurant foods, that is understandable. When I go to a buffet, I am very careful what I eat, mostly vegetables and high fiber foods. But, there are always obese folks there who have multiple plates of food, including lots of friend foods and sweets. When I have pizza out, I get the smallest one without cheese, but I see folks eating the largest size covered with a thick layer of cheese. These people are usually very obese. It's easier to eat healthier at home if you put you mind to it, not everyone can do that. If I gain a lb. I cut back on how much I eat for a day or two. It takes discipline to maintain a healthy weight these days, not everyone has that. Still, different things work for different people.
And, when I was young, people were far more active compared to now. Children were outside playing, running and walking all day long. We walked to school and played games outside. I almost never see kids playing outside these days. The age of the free range child is over.
Additionally, metabolism can change when people's weight goes up and down, eventually slowing it down to the point where it's extremely hard to lose weight. We had chemicals in the food since I was a kid in the 50s and we ate our share of junk food, including chips, processed cakes, ice cream bars etc. I think the fact that we were so active probably kept us thin, but a lot of us ate more and were less active once we reached adulthood. That's what happened to both of my sisters.
RFKjr doesn't have a clue as to why people are obese. The man isn't mentally stable imo. Sure it would be good to have fewer processed foods, but plenty of fresh foods are available now. There are even frozen dinners that are healthy with few or any unhealthy chemicals added, like Amy's Vegan meals, so we have lots of choices. Beans are very cheap, healthy and tasty if you make them correctly. It's just hard for people to change their habits and a lot of people are clueless when it comes to nutrition.
Sorry for the nutrition lecture, but it pisses me off when people think RFKjr is going to make anyone healthier or that decreasing processed foods is going to make everyone thinner. Once eating habits are established they can be hard to change.