The Moderna coronavirus vaccine has a fun little catch

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We are all excited that companies appear to be competing with coronavirus vaccine efficacy rates. All the most recent data seems to indicate that COVID-19 vaccines will be more effective and ready sooner than many of us anticipated. While this is all great news, there is — as usual — a catch. It turns out that the Moderna vaccine may not prevent transmission of COVID-19.

That may sound confusing. Isn’t the whole point of getting a novel coronavirus vaccine to make sure that the disease doesn’t spread? Yes, and also, vaccines only specifically protect the people who receive them. "They [vaccines] do not show that they prevent you from potentially carrying this virus transiently and infecting others," Tal Zaks, the chief medical officer at Moderna, told Axios.

So then, a person who gets the Moderna vaccine is unlikely to get sick with COVID-19, but they may still be able to transmit it to others. To complicate matters, Zaks said that he does think that it’s likely that the vaccine will prevent transmission, but that there is no scientific proof that this is the case, Insider reported. Basically, Zaks is covering Moderna’s legal bases by not overpromising what their vaccine could mean for public health.

"When we start the deployment of this vaccine we will not have sufficient concrete data to prove that this vaccine reduces transmission,” Zaks said. In other words, the vaccine may be able to prevent transmission, but Moderna won’t be able to prove that — scientifically speaking — until after the vaccine is released.

Zaks said that he’s concerned that the public may "over-interpret" the recently published vaccine trial results — which suggest that the Moderna vaccine is 94.5% effective at preventing severe cases of COVID-19 — and assume that once it’s released, life will just go back to normal, Insider reported. Unfortunately, that’s not the case.

"I think it's important that we don't change behavior solely on the basis of vaccination," Zaks told Axios. Hard agree. A widely available vaccine will definitely be a major game changer that will save a lot of lives, but we’re still going to have to keep our heads in the game if we really want to beat this virus.