New evidence proving the benefits of mixing two Covid vaccines could impact the Irish rollout from next month, a leading virologist has said.
The National Advisory Committee on Immunization (NIAC) is examining the option of mixing vaccines based on new data and is also looking at the 12-week gap between AstraZeneca doses.
Dr Anne Moore, a virologist at University College Cork, said new studies in Spain and the UK show mixing vaccine types to be effective and safe.
Dr Moore said the AstraZeneca and Pfizer vaccines stimulate antibody responses and that by using an mRNA vaccine as the second injection, after AstraZeneca, the T cell response is also enhanced.
Describing both biochemical actions as “important” for protection, she said in an ideal world without the pressures of a pandemic, this could have been used from the start.
“In June and over the summer we will have more decisions and more information,” said Dr. Moore.
“I imagine NIAC will again develop updated guidelines, based on testing.
And we could see giving a different vaccine in the boost (second jab).
Dr Marco Cavaleri, head of the European Medicines Agency (EMA) for Biological Health Threats and Vaccines Strategy, said the agency is also reviewing these new studies and the mixture appears to provide “an immune response robust”.
However, Dr Moore said that NIAC is unlikely to narrow the gap between AstraZeneca doses to four weeks instead of 12 weeks.
“We know that if you give the adenovirus shots too early, you don’t see any boost,” she said.
“We know that it takes at least eight weeks to give you a good level of efficiency.”
This is based on years of research on this type of vaccine, she said.
In England the gap is now eight weeks in some cases, and the Northern Department of Health has said GPs are delivering “an interval of around 10 weeks.”
About 150,000 health workers as well as thousands of vulnerable people aged 16 to 64 at “very high risk” of Covid-19 in group 4 of the vaccine list received an injection of the AstraZeneca vaccine.
“I think people are right to be concerned and understand what’s going on, but also to understand that the risk is minimal,” said Dr. Moore.
Dr Moore will be vaccinated next week. “I will take any vaccine that is offered to me,” she said.
She also said she was “absolutely worried” about the prevalence of the Indian variant in the UK.
“The Indian variant is much more transmissible. We have to try to avoid variations, that’s the first thing.
However, it is here and we need to track it down and eliminate it.
For this reason, she is not yet in favor of traveling abroad for non-essential reasons.
“We have to try to make sure we don’t make this fatal mistake by saying that some of us are vaccinated now, so let’s go. We’re almost there, we just have to hold on. “
Meanwhile, the EMA yesterday approved the use of the Pfizer vaccine for children aged 12 to 15.
Fergus Sweeney, the Irishman who heads the EMA clinical studies and manufacturing working group, said that doesn’t mean every child should get the vaccine; it is just “one option” and each country must assess its local situation.