Because the NHS vaccination programme continues throughout the UK, scientists steered folks might solely have partial immunity after a single dose of the vaccine and will wait till they’re absolutely protected with a second dose.
It comes after a number of the folks receiving the brand new Pfizer/BioNTech vaccine mentioned they had been wanting ahead to hugging their family members.
Dr Simon Clarke, affiliate professor in mobile microbiology on the College of Studying, mentioned: “The reward of the Pfizer vaccine rollout has not fairly are available in time for Christmas.
“It takes 4 weeks from the primary jab of the Pfizer vaccine for somebody to develop immunity to Covid-19.
“If somebody is in receipt of the vaccine immediately, they should wait three weeks to get the second jab after which one other week for immunity to develop.”
Dr Julian Tang, a medical virologist from the College of Leicester, mentioned: “Sometimes, vaccine responses might peak after two to 4 weeks – and these might take longer within the aged resulting from ‘immunosenescence’, the place the immune system in older folks responds extra slowly and fewer aggressively to overseas antigens.
“As folks solely began receiving the Pfizer-BioNTech vaccine on December 8, and the second dose is due at 21 days after the primary dose, nobody can have had the second dose by Christmas.
“Lately launched knowledge from Pfizer means that the efficacy would possibly solely be 50-60% after the primary dose – which is kind of low.
“The trial knowledge reveals that the utmost safety of (over) 90% is simply achieved after the second dose.
“So folks nonetheless need to watch out regardless of having had one dose of the vaccine, as perhaps solely half of these is perhaps protected – till the second dose has been given.”
It comes as Professor David Salisbury, a former Division of Well being director of immunisation, mentioned extreme adversarial reactions to vaccines are extraordinarily uncommon.
He was commenting after the Medicines and Healthcare merchandise Regulatory Company (MHRA) mentioned on Wednesday that individuals with a historical past of great allergic reactions mustn’t have the Pfizer/BioNTech jab.
Prof Salisbury instructed BBC Radio 4’s At the moment programme that adversarial reactions occur “of the order of about one in 1,000,000 doses”.
He added: “Extreme adversarial reactions, allergic ones to vaccines, do occur however they’re very uncommon.
“They occur of the order of about one in 1,000,000 doses. And everyone who administers vaccines on this nation is educated to cope with them.”
Requested if there may very well be a spread of reactions because the vaccine is rolled out the world over, he mentioned: “They may occur. What will even occur is there shall be occasions after vaccination that truly don’t have anything to do with it.
“We must be very cautious to separate out coincidence from causality.”