Infectious disease experts are now in the process of reevaluating Holiday advice given the discovery of a new, apparently highly contagious COVID variant , now being called Omicron. This variant has so far been isolated in Europe, Africa, and Japan and has prompted governments, including the U.S., to stop some international travel. The impact of this variant can’t be properly estimated for several weeks, and we won’t know the level of protection US vaccines provide from it for several months. Those with plans for travel should plan to use masking and distancing.  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 (eg, children ages 5-11), 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