AstraZeneca vaccine appears to substantially reduce transmission of the coronavirus, study shows

Posted at 5:25 PM, Feb 03, 2021
and last updated 2021-02-03 17:25:12-05

(WXYZ) — Newly released data shows AstraZeneca’s vaccine may not only protect people from getting sick but also substantially reduce the spread of the coronavirus.

I’m excited to share this news. As you know, there are only two approved vaccines here in the US for COVID-19. And while both of them have amazingly high efficacy rates, they have not been shown to stop community spread of this incredibly contagious virus.

So that’s why this research is big news in the scientific world.

Now AstraZeneca’s vaccine was developed by England’s Oxford University. And in their trials, participants were regularly tested with nasal swabs to see if they had become infected with the coronavirus. Let me point out that no other large-scale human trials had done that – participants were only tested if they developed symptoms. S

o regular testing in the AstraZeneca trials found that there was a 67% reduction in positive tests in the participants who had received the first vaccine dose. However, that number did drop to about 50% after the second dose was given.

They didn’t do any contract tracing. But the Oxford researchers said that if the vaccine was just making infections milder, then the positivity rate would not change. Having said that, we really need more research before confirming that the AstraZeneca vaccine would indeed stop people from passing the infection to others.

AstraZeneca’s earlier results showed that the vaccine had an estimated 70.4% efficacy rate. But that number has been bumped up to 76%. And that’s because this new analysis included more trial sites plus another month of data.

Now the 76% protection rate started at day 22 - after the first shot – and lasted up until the next dose 90 days later. But that rate changed yet again when the doses were spaced out. When the participants got a second dose at 12 weeks or later, the efficacy rate rose to 82.4%. Which is fantastic.

On top of all that, the researchers found that the levels of antibodies were stable "with minimal waning by day 90." And no participants died or were hospitalized.

AstraZeneca just finished enrollment last month for their phase 3 trial. So I don’t expect that they’ll get authorization until late March if all goes well.

Now, while it’s great that AstraZeneca’s vaccine has shown to be promising as well as Johnson & Johnson’s vaccine, I want to make sure that no one waits for any particular vaccine. It’s important that once you are given the green light to get vaccinated, that you do it right away. It’s the best way for us to return to normal life in the near future.

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