Do you suggest to sell stocks after Omicron discovery?

Only if you want to lose money. Anyone who sold during the original Covid-related volatility (March, 2020) lost out. If you are a long term investor, this will be a small blip. There is no reason to think this time is any different.

Also consider this news had unfortunate time: the day after a holiday, the market closing early, low volume, etc. It would be the perfect time for large institutions to shake out any weak retail investors.

Timing the market i usually easier said than done. When do you buy back? What if the market goes down initially and then bounces back, are you still a seller or do you buy?

I have a strategy to bring forward some of my regular investments if the market dips and sort of average into that.

I still have my bouillon, chicken and beef.

It depends on what your intention was when buying the stocks in the first place. I've only invested in low cost index funds and gold outside of my fun bucket, with the expectation that the value will fluctuate over the years. I don't intend to sell any time soon. If your investing strategy was designed to be more actively managed, your answer might be different.

Did you sell your stocks when covid orignally hit?

Yes, sell all stocks and buy bitcoin

If it alters the reasons you bought the stocks in the first place, perhaps.

What stocks and why? This question is rather vague.

Too late.

Current vaccination is not going to work, so another year will go into development and trials and again there there will be lockdown imposed So even if still in 1% profit, book it and buy the dip

Buy the dip!