The B.1.1.7 coronavirus variant first identified in the United Kingdom is now the most common strain of Covid-19 in the United States, according to US Centers for Disease Control and Prevention Director Dr. Rochelle Walensky.
Americans are being warned to avoid traveling to Canada because of COVID-19 variants that are circulating around that nation.
The Centers for Disease Control and Prevention is recommending Americans not travel to Canada at this time, noting that even fully vaccinated travelers are at risk of getting and spreading the virus variants.
The U.S.-Canada border remains closed to nonessential travel.

U.S. and Canadian flags fly atop the Peace Arch at Peace Arch Historical State Park on the border with Canada in Blaine, Wash., on May 17, 2020.
The reason for this new warning is because the COVID-19 variants, which are more easily transmitted, are rolling through pockets of Canada. In British Columbia, two variants are leading to the spike with rising hospitalizations, according to an article posted by the Canadian media outlet CBC. The two variants, one first spotted in the United Kingdom and the other in Brazil, have caused the surge in recent weeks.
The Brazil variant led to the closure of the Whistler ski resort, which saw a spike in cases after visitors began spreading the variant in February.
The CDC recommends that those who must travel to Canada should be fully vaccinated, wear masks and stay socially distant. The CDC also recommends getting tested 3-5 days after traveling to Canada.
Now that you’re vaccinated, here's what you can and can’t do
When are you fully vaccinated?
You are fully vaccinated 2 weeks after receiving the Johnson and Johnson vaccine, or 2 weeks after receiving the second dose from Pfizer or Moderna.

After being vaccinated, Americans receive a white COVID-19 vaccination record card from the CDC, as shown above.
What you can do
CDC guidance contains activity recommendations for fully vaccinated people in private settings and includes:
Visiting with other fully vaccinated people indoors without wearing masks.
Visiting with unvaccinated people from one other household indoors without wearing masks or staying 6 feet apart if everyone in the other household is at low risk for severe disease.
Refrain from quarantine and testing if no symptoms of COVID-19 are experienced after contact with someone who has COVID-19.
The CDC has also updated its guidance to say fully vaccinated people can travel within the U.S. without getting tested for the coronavirus or going into quarantine afterward. Read more about that here:
For the most up-to-date guidance from the CDC, go to the CDC's COVID-19 site.
Precautions in public
The CDC says that anyone who is fully vaccinated should continue to take these precautions when in public, when visiting with unvaccinated people from multiple other households, and when around unvaccinated people who are at high risk of getting severely ill from COVID-19:
Wear a well-fitted mask.
Stay at least 6 feet apart from people you do not live with.
Avoid medium and large in-person gatherings.
Get tested if experiencing COVID-19 symptoms.
Follow guidance issued by individual employers.
Follow CDC and health department travel requirements and recommendations.
10 things to know about vaccine side effects
Here’s a list of 10 things you should know about potential COVID-19 vaccine side effects, according to the Centers for Disease Control and Prevention and Harvard Medical School:
- The Pfizer-BioNTech COVID-19 Vaccine and Moderna COVID-19 Vaccine both require two shots in order to get the most protection. You should get the second shot even if you have side effects after the first shot, unless a vaccination provider or your doctor tells you not to get it.
- Side effects from the second injection may be more intense than the ones you experienced after your first shot.
- The most commonly reported symptoms are pain, redness and swelling at the site of the injection. Other common symptoms reported include tiredness, headache, muscle pain, chills, fever and nausea.
- You may take acetaminophen, aspirin or antihistamines for any pain and discomfort you may experience after getting vaccinated — as long as you have no medical conditions that prevent you from taking them normally.
- It is not recommended that you take pain relievers before being vaccinated in an effort to prevent side effects. They may interfere with the vaccine’s effectiveness.
- If you have pain at the vaccine’s location, keep the arm active and use a clean, cool, wet washcloth over the site.
- For a fever, drink plenty of fluids and dress lightly to remain as cool as possible.
- The symptoms should improve within two or three days.
- Call the doctor if redness and/or tenderness at the injection site worsen after 24 hours.
- Call your doctor if any other symptoms seem to be worsening or not improving after two to three days
Common questions
Can I get COVID-19 after being vaccinated?
Like other vaccines, such as the flu shot, the COVID-19 vaccines work by teaching the immune system how to recognize and fight the virus that causes COVID-19. It typically takes two weeks after vaccination for the body to build immunity against the virus, according to the Centers for Disease Control and Prevention.
Because of this, it is possible for a person to get COVID-19 before or just after vaccination, and then get sick because the body hasn’t had enough time to develop protection.
Dr. Michael Lindberg, chief medical officer at Monadnock Community Hospital in New Hampshire, said that while possible, it’s “very uncommon” for someone to become infected with COVID-19 after vaccination.
Should I still get tested after getting vaccinated?
If you’ve been vaccinated and are showing symptoms of COVID-19, then yes, you should get tested.
If you have been vaccinated and don’t have symptoms, however, you don’t need to get tested even if you suspect you’ve been exposed to the virus, per guidance from the Centers for Disease Control and Prevention.
When will we hit herd immunity?
Scientists estimate that potentially 75% to 85% of the population needs to be immune to reach herd immunity for COVID-19. Some estimates are higher, at around 90%. As of March 29, 15.8% of the U.S. population had been fully vaccinated, 28.6% had gotten at least one dose.
How long will we have to wear face masks?
Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said in February that even with increasing vaccinations, it’s “possible” Americans could still be wearing face masks and coverings in 2022.
Also contributing to this report: The News & Observer (N.C.), The Keene Sentinel (N.H.), Dayton Daily News (Ohio) and The Staten Island Advance (N.Y.)