Although vaccinated individuals can catch and spread the delta variant, the vaccine is extremely effective (around 95%, according to Dr. Julie Fischer, associate research professor in the department of microbiology and immunology at Georgetown University) at protecting against severe illness.
This means vaccinated travelers can move about with significantly reduced risk, especially if other preventative measures, such as social distancing and mask-wearing, are being used.
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Lastly, since vaccinated individuals can still be asymptomatically infected and transmit the virus to others, they need to consider who might be exposed. If you’re going to be in a location with unvaccinated people without the same protections, you could get them sick.
This is true for your destination and when you return home, which is why proper testing is key.
“Testing is helpful because it can identify someone infected and capable of transmitting the virus to others before they get on the flight,” said Fischer. “But, if you were exposed within those 72 hours before getting on the plane, you could transmit the virus to others three to five days later.”
That’s why the CDC recommends that even fully vaccinated travelers get tested three to five days after traveling internationally.