WHO explains breakthrough infections on fully vaccinated people

Health Watch

If you are fully vaccinated, can you still get the Coronavirus (Covid-19)? How frequent are breakthrough infections and what does the Covid-19 look like if you are fully vaccinated. The World Health Organisation’s (WHO) Dr Kate O’Brien explains.

Please explain breakthrough infections. How come people can still get the Covid-19 even when they’re fully vaccinated?
Dr O’Brien: The vaccines that we have against the Covid are incredibly effective.
People have seen the results from the clinical trials anywhere in the 80 to 90 per cent range of efficacy.
But, that doesn’t mean that 100 per cent of people, 100 per cent of the time are going to be protected against disease. There is no vaccine that provides that level of protection for any disease.
So we do expect in any vaccine programme that there will be rare cases of the disease among people who were fully vaccinated and certainly among some people who were partially vaccinated.
This doesn’t mean that the vaccines aren’t working.
It doesn’t mean that there’s something wrong with the vaccines.
What it does mean is that not everybody who receives vaccines has 100 per cent protection.
What we do want to emphasise for people is that it’s so important to get vaccinated because these vaccines are effective and it gives you a really good chance of not developing disease.

How frequent are breakthrough infections? If you are fully vaccinated, but happened to catch the Covid-19, what does that look like?
Dr O’Brien: So we’re learning a couple of things about breakthrough infections.
The first is that the degree of severity of the disease among people who have a breakthrough infection is less severe than the severity of disease among people who aren’t vaccinated.
So, vaccines are operating in a couple of different ways.
First, they’re preventing people from getting the disease at all.
Even when the disease does occur, people who are fully vaccinated, the severity of the disease is less.
The second question is about how often we’re seeing breakthrough infections.
We’re monitoring this carefully.
There’s a couple of things I want to say about breakthrough infections.
The first is that they are uncommon.
So this is not something that’s happening in an unexpected way, but they don’t happen equally among all different kinds of people.
People who are at increased risk of disease, so people with frail immune systems, people who are in older age groups, they have a greater risk of having breakthrough disease than other people.
So it’s not an equal risk of breakthrough disease.
The second point is that we’re seeing more cases of breakthrough disease, in part because people are stopping the other interventions that reduce the transmission of this virus.
So when the virus starts to transmit at a greater pace and with greater frequency, there’s a lot more exposure that everybody has, including people who are vaccinated.

People may be wondering if they can still catch the Covid-19 even after being fully vaccinated and if they can still infect others, then why vaccinate?
Dr O’Brien: This is a question that lots of people are asking.
I want to emphasise that vaccines do a number of different things to protect you and to protect others.
We’ve talked about how the main function of vaccines is to protect you against getting disease.
We’ve also talked about the fact that if you were to get the disease, a rare event among vaccinated people, but it does occur that your disease will be less severe than it would have been if you weren’t vaccinated.
The third thing that vaccines do is they reduce the transmission of the infection of the virus from one person to the next.
The way that vaccines do that is in a number of different ways.
The first is they can protect you against getting infected at all.
The second way that they work is if you become infected, you’re shedding that virus for a shorter period of time than if you weren’t vaccinated.
The third way that vaccines work is, again, if you happen to get infected, the amount of virus that you have in your nose, in the back of your throat that you are shedding and potentially transmitting to somebody is less of the virus.
There’s less density of the virus in you and so less risk that you transmit it to somebody else.
What is so critical is interrupting transmission of this virus has to be vaccines and all the other things that we’re doing, especially while people are still in the process of getting vaccinated.
Now isn’t the time for us to reduce those other interventions while we’re living in communities that don’t have substantial vaccination yet. – WHO