Perhaps ethically (debatable) but not legally. I as a person am under no legal obligation to stop covid.
Incorrect.
35 states already have laws on the books criminalizing the transmission of communicable diseases. Most of those laws were a reaction to the AIDS epidemic, but most of them were not limited to HIV or STDs. A prosecutor might also have the option to charge you with assault if you knowingly and deliberately try to spread COVID.
In March 2020, the Department of Justice circulated a memo reminding recipients of pandemic-related crimes. Many were about fraud (e.g. selling fake medicines), but it also included "purposeful exposure and infection of others with COVID-19." Because COVID-19 is classified as a biological agent under existing laws, it could even be prosecuted via some terrorism laws. Numerous states have also made it illegal to specifically threaten someone by saying you'll give them COVID.
And obviously, laws or emergency declarations which require you to wear a mask or take other actions are largely saying that yes, you have a legal responsibility not to spread the virus.
Obviously the vast majority of scofflaws are not arrested or prosecuted for refusing to wear a mask, and it is not illegal to refuse vaccination. Most legal action happens when the individual is being disruptive or engages in assault, or claims "I have COVID!" and then deliberately coughs or sneezes or spits on someone. There were also cases where individuals who violated social distancing rules were arrested (e.g. a barber who was privately giving haircuts in violation of the rules got busted in New York State) though such cases are rare. It would also be very difficult to prove in a court that "I got COVID from Trouble13 and no one or nowhere else."
However, it's been a long-standing legal principle that the state is properly empowered to enforce public safety, even if that means curtailing some liberties. I.e. you've always had at least some legal requirement not to spread the virus, and you most certainly do not have any legal right to spread a potentially lethal disease.
Morally, it is utterly and completely indefensible to say that "I can spread a deadly disease if I want." There are some potential mitigating factors; e.g. we needed many people to perform various jobs long before we had any vaccines or treatments. An essential worker who does everything they can to keep other people safe isn't morally responsible for spreading the virus. However, a worker (essential or otherwise) who doesn't care about the health and safety of others, and refuses to take steps to protect themself or others,
is morally culpable if others are harmed as a result of his behavior.
I.e. your selfishness, or hatred of government, or partisan mindset, is not sufficient to allow you to harm others. That's a pretty basic moral principle.