Infectious disease experts are still  reevaluating Holiday advice given the discovery of  the  highly contagious COVID  Omicron variant.  This variant has now been isolated in dozens of countries and now accounting for the  vast majority of new positive tests in the US according to the CDC. It has prompted governments, including the U.S., to stop some international travel. The impact of this variant still can’t be properly estimated though we are starting to have some reports from South Africa and the UK ( where Omicron earlier became  the preponderance of COVID infections). We won’t know the level of protection US vaccines provide from it for several months, but very early reports  indicate high infectivity and low severity of  Omicron infection.  Those with plans for travel should plan to use masking and distancing to improve their safety  Testing in advance of any gathering adds assurance that someone in the group is not unknowingly infected with COVID and thus capable of spreading the virus.  When a gathering includes elderly, pregnant, immunocompromised, or unvaccinated people (eg, children under age 5) or partially vaccinated people, testing for COVID before gathering becomes more important.  It will be necessary to make appointments well in advance if you plan to use a pharmacy for testing. Home antigen tests are now available in some pharmacies and big box stores (eg, Abbott’s BinaxNow), to keep on hand for the times they are needed. Masking when indoors adds another layer of protection to any gathering (though of course is impossible during a meal). See also these NYT articles: 

https://www.nytimes.com/2021/11/12/briefing/when-will-covid-end.html and

https://www.nytimes.com/2021/11/15/briefing/travel-coronavirus-holidays-thanksgiving.html