Pfizer injection relies on a live piece of genetic code that needs to be kept at -70C, making it easier and more expensive than a traditional Oxford vaccine.
Pfizer Inc and German partner BioNTech SE had produced over 70 million doses of their Covid-19 vaccine by the end of 2020. In total, the UK has ordered 40 million doses.
BioNTech said on January 11 that the companies were raising the 2021 delivery target for their Covid-19 vaccine to 2 billion doses, up from 1.3 billion, as they build new production lines and how more doses can be delivered out each vial.
However, delivery of the Pfizer vaccine to the UK will be cut by 15 to 20 per cent from January 25, due to delays in shipments due to work to increase capacity at their Belgian processing plant, sources said.
Why is there a delay between the first and second Pfizer injections?
The decision to widen the gap between the doses has contradicted criticism from GPs and scientists, after some elderly and vulnerable people said they would have to wait longer for a second they inject.
Regulators had previously stated that two doses should be administered between four and 12 weeks apart.
However, Dr Chris Whitty said widening the gap between the first and second injections could mean that the number of people vaccinated could double over three months.
“If there is more than 50 percent protection over that period, you have won. More people will be protected than would otherwise be the case,” he told a No. 10 news conference.
“Our strong view is that defense is likely to be well over 50 percent.”
However, on 20 January the UK’s chief scientific adviser said the UK needed to look “carefully” at the effectiveness of a single dose of the Pfizer / BioNTech coronavirus vaccine, after reports from Israel said the protection it provides could passed to be much lower than shown in tests.
Responding to Israeli claims that efficacy from the first dose of the Pfizer vaccine could be as low as 33 percent, Sir Patrick Vallance said studies showed that, from day 10 after vaccination to 21 days and beyond, it was “much more than 89 per cent”.
At the same time, the JCVI said it advises that people should have a second dose of another vaccine, rather than a second dose, if supply issues make it impossible to have two doses of the same medicine. .
A new study has found that a single dose of the Pfizer / BioNTech vaccine provided a “very high” level of protection from Covid-19 after just 21 days, without the need for a second “top-up” vaccine.
The UEA study, which has not yet been peer-reviewed, looked at data from Israel where the vaccine was distributed.
Although it is not yet known how long immunity lasts longer than 21 days without a second dose, researchers believe it is “unlikely” a significant decline in the next nine weeks.
But scientists warned that the risk of human infection had doubled in the first eight days after the Pfizer vaccine injection, citing a lack of caution as a possible cause.
According to the scientists behind the injection, the gap between doses of the Pfizer-BioNTech vaccine should not exceed six weeks apart.
Uguh Sahin, chief executive of BioNTech, said on February 12 that he would be comfortable pushing that gap to six weeks.
“As a scientist, I wouldn’t be worried if the second dose of the vaccine was given three weeks, four weeks, maybe five weeks, even up to six weeks which may be okay,” he told Sky News.
“It simply came to our notice then. As a scientist I believe it’s not good to go beyond six weeks. “
What’s the latest on the AstraZeneca vaccine at Oxford?
The Oxford vaccine was approved by the Medicines and Healthcare products Regulatory Agency on Dec. 30 and began distribution from Jan. 4.
Brian Pinker, 82, was the first to receive the vaccine, at Oxford University NHS Hospitals NHS Foundation Churchill Hospital Trust.