28 Jan 2022

How to reduce the risk of catching Omicron

From Checkpoint, 5:38 pm on 28 January 2022

As Covid-19 cases climb, just how can you minimise the risk of catching it. University of Otago infectious diseases expert Kurt Krause answers some questions for Checkpoint listeners. 

Prof Krause says nobody wants to get sick, but the good news is that if you are under 65, vaccinated and boosted, without risk factors, then generally the odds of getting a serious illness from Omicron is low, "and much more similar to say the odds of getting sick from the seasonal flu". 

"So that's quite good and it means for the vast majority of people, we're going to be able to handle this without any issues at all." 

If you're going to a restaurant or bar, where is the safest place to sit? 

"The biggest thing is can you eat outside? So outside is always better than inside. If you're inside, you want to be in a place that's wide open where people who are not eating are wearing masks, where the servers are wearing masks, and you have very, very good ventilation. 

"If you're in a very crowded place, loaded with people, nobody is wearing a mask, all the doors are closed, yeah, then I'm getting a little bit nervous." 

Should teenagers still be going to dance class? 

"Oh, that's another one that's tough too, because we've seen over and over again with coronavirus that kind of very vigorous activity, if you've got a super spreader, can be a significant event. So choir, music, exercise - these are some activities that are associated with some risk. 

"I think in this setting you have got to ask yourself, where is the activity happening and what kind of risk are you willing to bear? If you're in a small gym with few numbers of people and you've got good ventilation, maybe it's something that's worth the risk for you. On the other hand, if you're in a huge gym with large numbers of people and nobody wears masks, then it might be a different matter. 

"The other thing to consider is where in the Omicron outbreak this happens - so when there's very small numbers of cases, the risk is obviously significantly lower. But we've seen overseas, [in] all the places that Omicron goes to, the cases shoot up and there's quite a big peak, and then they shoot down. So during that peak time, that may be times where you avoid the restaurants, and you avoid the gym, and you avoid the dance class to just avoid that peak. It also depends, do you have a lot of young people at home who are healthy and vaccinated? Or do you have some people at home that are older and with more co-morbidities, so you don't want to be bringing anything home." 

What sort of checklist should you be going through when people are coming into your house? 

"So, if you've got strangers coming in or people that you're doing business with, they should be wearing a mask and you should be wearing a mask, and if possible, you should conduct your business outside. That puts you at very minimal risk. 

"If you're inside with people who you don't associate with on a regular basis, then you just want to be really cautious. 

"The friends [coming over] is another sort of tricky issue too, because if you're inside for a very long time with a large number of friends and it's going to be hard to convince people to keep the mask on, then can you switch all the activity outdoors? So, staying outdoors would be better, but there's a significant amount of risk about spending many hours inside with people. If somebody has Omicron, they could spread it rapidly amongst one another." 

What about double-dipping in food or sharing drinks? 

"Think about how viruses get transmitted, viruses like coronavirus. They're in the air in droplets, that's big. They're in aerosols, that's big. Surfaces, a little bit less important than we thought. Blood and body fluids, that's big. So I don't want to share blood and body fluids with anybody outside of your intimate partners. So, no double dipping, no sharing of food back and forth. You've got to be really cautious about all of that. But the only way that you can get it is through the air, through surfaces or blood and body fluids. So be cautious about all those things." 

In terms of the viral load that you are exposed to, how much impact does that have on how sick you get if you catch it for the first time? 

"That's a good question and it's tricky actually. Viral load is just really another way of saying how many viral particles are you getting exposed to. So, the more viral particles you are exposed to, the more likely you are to get infected, so that's easy, that's 100 percent, because there's just more odds. It's almost like viruses are like lottery tickets. If you've got more tickets, the more likely you are to win, or in this case lose the virus lottery. 

"Now the other question is if the person that is exposing you has a higher viral load, does it make you sicker? We don't really know in people. There's some suggestion in animals - I think there's a study in Syrian hamsters, believe it or not, that suggests that if you are exposed to more Covid, you're more likely to be sicker. So, we don't know yet in people. 

"Another thing that we do know is once you get coronavirus then the virus booms exponentially inside of you. And the people who can clear that viral load rapidly tend to do better than people who get a very high viral load and they have trouble clearing it. So that's an important concern - how much virus do you have growing in your system? And can you get rid of it, or can you not get rid of it?" 

Would you even be going out and about if you lived somewhere like Auckland where we know that it's a potential hotspot? 

"Yeah, it depends when and where. So I'm down in Dunedin, I don't think we've had an Omicron case yet in Dunedin. So less worry down here, [but] in Auckland much more worry. You do have to ask yourself; do you need to be out and about and what can you do to minimise your risk? 

"I was hearing Tony Blakely who is an epidemiologist - a really great scientist who was based in New Zealand, moved over to Melbourne - was talking I think yesterday or today about how during the peak of Omicron and infection cycle, a lot of people, particularly older people and immunocompromised people, may want to hunker down, may want to stay in, may want to go out. 

"I think if you do go out, you want to go to places that allow you to say eat outside, work outside, wear your mask. I've seen that we've got some restaurants now that have these bubbles, I don't know if you have those in Auckland, where there's sort of individual bubbles where families and small groups can eat and they're separate from everyone else and they're outside. 

"But yeah, I would always ask myself, do I want to go into this situation and is it a good situation to be in?"