As COVID-19 Variants Spread, Moderna Begins Work on a Vaccine Booster Shot

There are now several new variants of the coronavirus quickly spreading all over the globe. We’ve known about the so-called U.K. variant since last December, which seems to spread more quickly than the dominant strain.

Viruses usually mutate over time as they try to overcome barriers to infection. Influenza viruses are always trying to outwit the body’s immune system, which is why we need to get a new flu shot every year. Researchers say the vast majority of these COVID-19 mutations raise no more concern than the dominant strain; however, one strain seems to be more alarming than the rest.

Why This Variant is So Worrying

To block infection, the body makes antibodies that stick to the surface of the virus before destroying it. As the virus continues to spread, it gradually learns to evade these antibodies by changing form, making vaccines less effective.

That’s the case with the new variant first detected in South Africa back in October, officially known as B.1.351. The same is true of a new variant that first popped up in Brazil. These mutations allow the virus to spread more easily, but the jury is out on whether they’re more fatal or more likely to cause severe illness.

The CDC has just confirmed the first two cases of the South African variant in South Carolina. The two patients are not connected in any way and have no known travel history, which suggests community spread. The agency noted, “We have no evidence that infections by this variant cause more severe disease.”

Yet, scientists are worried the new variant could reduce the efficacy of the COVID-19 vaccines.

Pam Moore, who’s been studying B.1.351 at the National Institute for Communicable Diseases in South Africa, took the blood of patients previously infected with the original version of the coronavirus and exposed it to the new variant to see whether the antibodies could still fight off infection.

She says the new variant was much more resistant to the antibodies. “We saw that in half, the antibodies were significantly less effective against the new variant,” she told NPR.

That means those previously infected with the original virus may not have immunity against the new variant. 

As for the vaccine, Moderna recently released a study on its resistance to the new variants, but it has yet to be peer reviewed. It produced antibodies when exposed to all of the variants, but researchers found a sixfold reduction in its ability to fight off infection when exposed to B.1.351, compared with the earlier stage of the virus.

That put vaccine manufacturers on high alert.

However, scientists are quick to point out that what happens in the lab may not play out in real life. The body has many different ways of fending off infection, so there’s hope that we may be looking at just a slight drop in efficacy. Considering both the Moderna and Pfizer vaccines are over 94% effective, even a small dip in efficacy may not be catastrophic.

How Will the Booster Shot Work?

Regardless of how things play out with the new variant, Moderna isn’t taking any chances. The company recently announced it’s developing a booster shot for the new variant, which would make the existing vaccine even more effective.

Stephen Hoge, the president of Moderna, recently told The Washington Post, “The virus is changing its stripes, and we will change to make sure we can beat the virus where it’s going.”

Several days later, Pfizer and its German partner BioNTech said it will do the same to make sure its drug stays just as effective.

Pfizer CEO Albert Bourla told Bloomberg news, “Every time a new variant comes up, we should be able to test whether or not [our vaccine] is effective. Once we discover something that is not as effective, we will very, very quickly be able to produce a booster dose that will be a small variation to the current vaccine.”

Representatives at Pfizer remain optimistic, considering the “flexibility” of the mRNA technology used to create the vaccine. Unlike DNA vaccines, scientists can easily adjust the code of the mRNA vaccine as new variants arise.

“If the virus mutates in a way that an update to our vaccine is required to continue to provide protection against COVID-19 disease, we believe that the flexibility of the mRNA vaccine platform will allow us to move quickly to adjust the vaccine as needed,” the company said in the statement.

The existing vaccines will be our best chance at immunity, but they may be slightly less effective when exposed to the new South African variant. Health officials are urging folks to double up on face masks to prevent the spread.

Moderna says there is enough immunity to protect people, but the company is still launching a series of preclinical studies as well as a phase 1 trial to begin development on a third booster shot.