Professor Luke O'Neill says there's 'no question' that new variants of COVID-19 are a cause for concern.
The Trinity College immunologist said there's been some good news that the Pfizer vaccine appears to be effective against strain first detected in the UK, but there's still a need to 'double down' on the likes of mask-wearing.
Recent weeks and months have seen the emergence of the new strains of the virus that scientists believe are more transmissible.
About 45% of new COVID-19 cases here are linked to the British variant, and there have been three cases of the South African strain.
On today's Pat Kenny Show, Professor O'Neill said there's been a 'frenzy of activity' as scientists work to find out more about the new strains.
He explained: “It’s a cause for concern, there’s no question, because they spread more - that makes it more difficult to control.
“What that tells us we must double down on all the measures.
"It doesn’t make you any sicker, which is good news - but it’s a numbers game, so the more people who are infected the more illness you’re going to see.”
He pointed to Germany as one country taking the variants particularly seriously, with Chancellor Angela Merkel and her government mandating people wear medical-grade masks on the likes of public transport or in the workplace.
Professor O'Neill said all the research is still a work in progress, but Pfizer just yesterday reported promising results that their vaccine could be effective against the UK variant.
In terms of the South African variant, Professor O'Neill said: "There's some evidence in a test tube the [vaccine's] antibodies are less effective against the South African strain - it still works, but you need more of them.
"Even if the antibodies aren't quite as good, they can do something of a job. The second thing that's good is the t-cell part - we don't know yet, but it might be normal."
He did stress a company like Pfizer will be able to change their vaccine in as little as six weeks if their existing jab is found to be less effective.
Mucus and COVID-19
Elsewhere, Professor O'Neill highlighted a 'fascinating' study by Chinese researchers about the role mucus in the body may play in fighting COVID-19.
He observed: “Even though we don’t like mucus - you can call it spit… a really good study took nearly 2,500 samples of mucus from people with COVID-19. They had 2,000 controls to compare it to, and they assessed it very, very carefully.
“They found there were 375 proteins in the mucus of the COVID people, and not in the normal mucus. Now they’re wondering what those proteins do.
“It turns out there was protein called Complement… which helps antibodies do their job. It’s a good sign to have it in mucus, and it just shows you how mucus is beneficial. There are proteins in mucus that are fighting the virus."
Professor O'Neill said every time we blow our nose we're blowing out a "very complex mix of biochemicals that’s bringing you all kinds of benefits".
He observed: “The virus wants you to cough it out, because it spreads it through droplets.
"Of course you can’t stop coughing sometimes, but mucus is your friend - and a reason to wear a mask, as that keeps the mucus moist in your nose and throat.”
The leading immunologist also said a “really robust” study has come out to assess COVID-19 patients’ sense of taste and smell.
He explained: “73% have a smell defect - that just tells you how common that is. It’s a real hallmark [of the virus].
“46% had a taste problem - that was less common, strangely.
“Very interestingly, with severity taste and smell came back. That was unexpected, because they thought it might be the other way around.
“If it turns out if you’ve lost your sense of taste and smell you may be doing better with the virus overall. If that’s not a feature or it begins to come back… that might mean it’s heading towards a more troublesome disease."