"It's important to remember that a vaccine doesn't create one type of antibodies, it creates a whole host of antibodies and it's very hard for a virus to escape all of those, especially when it's happening so fast – meaning this mutation is rather new. It's not something that's been evolving for some time," Adalja told CNN on Wednesday.
Some background: Scientist say that a new variant of Covid-19 was first detected in the United Kingdom and can likely spread faster than others.
The variant has also been detected in Denmark, the Netherlands and Australia, according to the World Health Organization. In South Africa, a different coronavirus variant has been reported, the WHO's technical lead for Covid-19, Maria van Kerkhove, said Monday.
Adalja said vaccines also stimulate other parts of your immune system that are important to fighting off viruses.
"I don't think there's any worry at this point," he said. "Moderna, Pfizer, they're doing tests to make sure, but everything that we're seeing so far is really reassuring that these vaccines will be able to take this strain out just like they take out... the prior, older strains."
Adalja added that the concept of virus mutations is not uncommon.
"Viruses like this, coronaviruses that have RNA genetic material, they mutate a lot," he said.