The strain of Omicron being monitored by experts should cause “mild” concern, Jason Leitch has said, though so far there is no sign it produces more severe disease.
Scotland’s national clinical director said the BA.2 sub-variant appeared to be more transmissible than Omicron, though the difference was not great.
On Tuesday, the First Minister, Nicola Sturgeon said 26 cases of BA.2 had been confirmed in Scotland, saying it was able to “outrun” the main Omicron variant.
Speaking to Holyrood’s Covid-19 Covid Recovery committee, Prof Leitch said the BA.2 variant is quickly becoming dominant in Denmark.
Asked how worried people should be about it, he said “mildly”.
He said: “It appears in the early research to have one advantage.
“It’s tricky to be sure but the secondary attack rate, which is the number of people who get it when a positive arrives – such as in a household for example – appears to be slightly higher in BA.2 than with BA.1.”
He said this would mean about 40% of people in a household would get BA.2 if someone has it, versus around 30% for BA.1.
This was not a “huge difference”, he said.
Prof Leitch continued: “The good news is that it does not cause more severe disease.
“You may be slightly more likely to catch it, particularly if you are unboosted, but you won’t end up sicker than you would have with Omicron.”
Scottish Conservative MSP, Murdo Fraser, asked if someone who had been infected with BA.1 could go on to be reinfected with BA.2.
Prof Leitch said: “Yes, you can get any version of it again. It’s very unlikely within three months, but not impossible.
“One of the things we’re seeing with Omicron compared to Delta and Alpha is higher reinfection rates.
“Everything about this virus is coming down to immunity.”
