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Why fully vaccinated people can get COVID, but are still better protected

Earlier this week, the HSE said 10% of people who tested positive for COVID on Monday had been va...
Paul O'Donoghue
Paul O'Donoghue

16.09 23 Jul 2021


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Why fully vaccinated people ca...

Why fully vaccinated people can get COVID, but are still better protected

Paul O'Donoghue
Paul O'Donoghue

16.09 23 Jul 2021


Share this article


Earlier this week, the HSE said 10% of people who tested positive for COVID on Monday had been vaccinated.

On Thursday, it was revealed that between mid-May and mid-July, Ireland recorded 70 COVID deaths.

Of that number, 12 had received two doses. Of that 12, two were fully protected.

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This means more than 14 days had passed since they got their second dose.

So, why are fully vaccinated people still getting COVID and dying from it?

It's because the vaccines are not 100% effective, meaning there will always be some "breakthrough" cases.

But as the effectiveness is so high, a vaccinated person is estimated to be far less likely to die from COVID versus someone who is unvaccinated.

Take the Pfizer vaccine - a study published in the Lancet in May looked at the effectiveness of Israel's vaccine rollout by examining COVID infections between January and April.

One comparison was between someone who was unvaccinated, versus someone who waited 14 days after receiving two doses of the Pfizer jab.

It found just 5% of cases were in people who were vaccinated, while 95% were among those who are unvaccinated.

So fully vaccinated people can still get the virus - but they are far less likely to do so.

There were similar results for deaths - just 3% were among the fully vaccinated.

So on average out of 1,000 COVID deaths, 970 were unvaccinated.

While just 30 were fully protected, meaning 14 days after a second dose.

'More deaths among vaccinated people'

Liam Fanning, immunovirology professor at University College Cork, also points to recent figures showing a similar pattern in the US state of Texas.

"Texas has had nearly 9,000 COVID deaths since February. All but 43 were in unvaccinated [people]. So 99.5% of COVID-related deaths were among the unvaccinated", he says

He says this means for every 1,000 COVID deaths, it could be expected that over 990 would be among people who are unvaccinated - while fewer than 10 would be in those fully vaccinated.

Although this differs slightly from the study in the Lancet, the findings are similar.

There will likely be more deaths among fully vaccinated people in the coming weeks. This is because of the shrinking pool of unvaccinated people in Ireland, as two-thirds of adults are now fully protected.

But this is why expected COVID deaths are dropping too.

Earlier this week, Tánaiste Leo Varadkar said previously it was expected there would be 10 deaths among every 1,000 virus cases. For every 1,000 cases, officials expect just one death.

Think of it this way: if everyone in Ireland is fully vaccinated, 100% of COVID deaths will be among the vaccinated population.

But the total number of COVID deaths would drop sharply, likely by more than 90%.

The Delta variant changes things a bit - it’s estimated the Pfizer vaccine effectiveness for preventing infection drops to about 79% in the new strain. But this is still a high rate, and it’s estimated to still be 96% effective in preventing hospitalisations.

The upshot of all this is some fully vaccinated people will get COVID. And some will die from the virus.

But the chances of either happening if you wait 14 days after getting two doses fall by about 80% - 90%.

Main image: A man reacts as a health worker collects a swab sample during a COVID-19 test. Picture by: SOPA Images/SIPA USA/PA Images

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COVID Deaths Covid Fully Vaccinated Leo Varadkar Liam Fanning Why Fully Vaccinated People Get COVID

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