Current Guidance for Travel to the U.S.
While many countries have recently opened travel to U.S. visitors with varying conditions (vaccination proof, negative covid tests, quarantine, etc.), the same courtesy has not been offered to those traveling to the U.S. (outside of family, and other very limited, largely non-business reasons). The CDC has not updated the list of countries where visitors are prohibited from entry. Unfortunately, this prohibition represents a large base of potential international people who are IAM members (EU, UK, among others).
U.S. Secretary of State Antony Blinken is looking at entry from the EU, UK and is in task force discussions with other countries on re-opening the U.S. to business travel, but as of today, has set no firm date/deadline for re-entry.
The Biden Administration has not changed its position with respect to "digital" vaccine certificates - meaning, proof of vaccination is not likely to be a standard for entry. Negative COVID testing may be incorporated (as that is the current requirement for all eligible international passengers arriving to the U.S.), but the U.S. is much more likely to look at current outbreaks, alongside overall population vaccination rates for countries, when determining entry.
The New York Times updates the country vaccination rate (based on available information) every other day. This may be a good indicator of country entry, when the Administration makes a decision. If at all possible, there is likely to be an inclination to open up land-connected countries (i.e. EU) all at once, versus a country by country basis.