Travel-related stocks took a hit on Friday after the United States, Canada and several European and Asian countries placed travel restrictions on southern African nations due to a new strain of COVID-19.The outbreak, known as the omicron variant, was flagged by the World Health Organization as highly transmissible.ADVERTISING Trending Now The U.S. has restricted travel from South Africa and seven other African countries – Botswana, Zimbabwe, Namibia, Lesotho, Eswatini, Mozambique and Malawi. American citizens and permanent residents won't be subject to the policy but must still present a negative COVID-19 test to re-enter the U.S. The European Union’s 27 member nations also placed a ban on travel to the southern Africa region.As expected, the markets reacted swiftly during the week’s last day of trading as travel and aerospace shares fell more than the broader market, according to CNBC.Airplane manufacturer Boeing Co. saw shares drop 5.4 percent to $199.21.United lost 9.6 percent to close at $42.26.American slipped 8.8 percent to $17.75.Delta fell 8.3 percent to $36.38 a share.Delta and United have flights to South Africa. United has 87 flights scheduled there for the month of December, and Delta has 35.According to CNBC, United has no plans to change its schedule when it resumes nonstop flights to and from Newark-Liberty International and Cape Town, while a Delta spokesperson said “Delta will continue to work closely with our government partners to evaluate any changes to U.S. policy.”Marriott was down 6.5 percent at $147.44, while Hilton dropped 6.3 percent to $136.21. Adblock test (Why?)