The press release detailing the further easing of restrictions can be found here:
The relevant portion for travel from US:
Facilitated entry into Switzerland
The Federal Council has also
decided to relax the entry requirements for Switzerland, as proposed
in the consultation. The quarantine obligation is lifted for those
arriving from the Schengen area. Only unvaccinated or unhealed people
who arrive in Switzerland by air should be tested. Only the contact
details of those traveling by plane are recorded. Switzerland is also
loosening the entry restrictions still in place for third-country
nationals who can prove they are vaccinated. The relevant list of
countries of the State Secretariat for Migration has been adapted.
Citizens of third countries such as the USA, Albania or Serbia can
Travelers from a country with a disturbing variant of the virus
The Federal Office of Public Health's list of at-risk countries has
been reduced and covers only those states or regions in which variants
of the virus are circulating which are of concern to Switzerland.
People vaccinated or cured from one of these areas are not subject to
testing and quarantine, as long as it is certain that the vaccine
offers good protection. Those who are neither vaccinated nor cured
must instead submit a negative PCR test or rapid antigen test and
quarantine themselves upon arrival in Switzerland.
In concrete terms, this means that people who have been vaccinated or
cured must neither submit a negative test nor go to quarantine even if
they come from a country, such as India or the UK, where the delta
variant predominates. Vaccines used in Switzerland offer slightly
reduced but still very good protection against this variant.
Also: The term of protection is now 12 months. Anyone who has received the two doses of vaccine is therefore exempt from quarantine for 12 months. For those who have recovered from the disease this period remains 6 months.