The director of the National Virus Reference Laboratory (NVRL) has warned that it would be “hubristic” to think that the three identified cases of the Indian variant were the only ones in Ireland.
Dr Cillian De Gascun said that the majority of 100 cases of the so-called Indian variant (B1617) identified in the UK to date were travel-associated,
But he told RTÉ radio’s Today with Claire Byrne that he did not think there was any evidence yet from the UK of localised community transmission.
Similarly, in Ireland, there was no evidence yet of localised community transmission.
Two out of three cases of B1617 identified in Ireland were travel related, but he did not have information on the third case as it had not been referred to the laboratory.
“We don't yet know how they have emerged - we believe it's likely that they have emerged from a setting of persistent infection in an immunocompromised individual so therefore we need to be vigilant and from a surveillance perspective, we need to be on the lookout for new variants emerging," he said.
“This lineage B1617, it's of concern because of what we're seeing in India, because it's increasing in prevalence in India, but it's been reported in a number of other countries probably since October last year - why is it kicking off now?
“India is unfortunately going through a very bad spell or is it kicking off now because it's had an opportunity to evolve, adapt and to become more used to us as humans?”
When asked about mandatory hotel quarantine and if India should be added to the list of countries for which it was necessary, Dr De Gascun said a number of factors had to be taken into account.
“It's very difficult to have a perfect system, to say with 100% confidence that our system is so perfect that there are only three cases and we found all three of them. I wouldn't be hubristic enough to say that, but I do think we have a good surveillance system in place.”
Dr De Gascun said he would be more concerned at present with the levels of the South African variant, of which there were 55 cases in the country and the Brazilian variant, of which there are 24 cases here.
He was confident that the NVRL’s sequencing system was effective.
"Since the middle of January we've done about 9,5000 sequences - so they're tiny numbers in the context of 9,500 sequences, but at the same time the numbers are continuing to increase, part of that is they are increasing because of our public health colleagues doing their investigations and contact tracing and tracking down networks of transmission in the community.
“We have identified cases where there is no obvious travel link so it remains to be seen what is the situation with B1617.
“The plan is to do smart sequencing - at the moment we're about 1,000 sequences per week, which based on our current five day case number average which is 364 as of yesterday, over seven days that's about 2,600 or 2,700 cases.
"We know from our experience of those cases about 30% to 40% will have insufficient viral loads for sequencing which gets it down to 1,300 - so we're probably doing close to the majority of sequences that we need to do.
“We are building capacity, but it is really important that we target our sequences accordingly because we're at about 90% of B117 - the variant first reported in the UK.
“It's not terribly cost effective to sequence 90% of B117 when that's what you've got so you want to try to be smart - what we're looking at in a targeted fashion is imported cases, specifically looking at variants of concern for people with a travel history.
"We're more focused on people who have been vaccinated, we're looking for evidence of vaccine escape, people who were vaccinated and then tested positive, a small number who will have that. That's ok, the vaccine is intended primarily to prevent serious illness and death.”
As for vaccinating children, Dr De Gascun said he did not know if it should happen yet.
“If we go back to fundamental principles from the point of view of community-level protection or so called herd immunity, if we leave a large swathe of the population completely unvaccinated and unprotected - it's very difficult to see how you get to that level.”
The situation would have to be re-examined when there was real-world evidence.