The authorization recommends dosage intervals of between 4 and 12 weeks.
The United Kingdom’s Medicines and Healthcare products Regulatory Agency (MHRA) announced today it had provided an emergency authorization of the AstraZeneca and Oxford COVID-19 vaccine, AZD1222, for individuals 18 years and older.
“Today is an important day for millions of people in the UK who will get access to this new vaccine. It has been shown to be effective, well-tolerated, simple to administer and is supplied by AstraZeneca at no profit,” AstraZeneca CEO Pascal Soriot, said. “We would like to thank our many colleagues at AstraZeneca, Oxford University, the UK government and the tens of thousands of clinical trial participants.”
The other recently approved COVID-19 vaccine in the UK, Pfizer and BioNtech's BNT1622b2, had a dosing interval of 3 weeks between the initial vaccine and the booster shot; however, in a departure from the dosing schedules done during clinical trials, the AstraZeneca and Pfizer and BioNtech’s vaccines are now being recommended in an interval of between 4 and 12 weeks in the UK.
According to a report in the Associated Press, this change in dosing schedules is a deliberate part of a UK strategy to get some level of protection to people more quickly.
The AZD1222 vaccine was developed by the University of Oxford and its spin-out company, Vaccitech. It uses a replication-deficient chimpanzee viral vector based on a weakened version of a common cold virus, adenovirus, that causes infections in chimpanzees and contains the genetic material of the SARS-CoV-2 virus spike protein.
After vaccination, the surface spike protein is produced, priming the immune system to attack the SARS-CoV-2 virus if it later infects the body.
Questions arose shortly after the data was initially reported in late November about its efficacy. However, additional data was published in The Lancet in early December, and the MHRA’s decision was based on independent advice from its Commission on Human Medicines following a rolling review of trial data that included an interim analysis of the phase 3 trial.
“The regulator’s assessment that this is a safe and effective vaccine is a landmark moment, and an endorsement of the huge effort from a devoted international team of researchers and our dedicated trial participants. Though this is just the beginning, we will start to get ahead of the pandemic, protect health and economies when the vulnerable are vaccinated everywhere, as many as possible as soon possible,” Professor Andrew Pollard, director of the Oxford Vaccine Group and chief investigator of the Oxford Vaccine Trial, said.
One of the differences between the AstraZeneca vaccine and the Pfizer vaccine is the storage conditions. The former vaccine can be stored, transported and handled at normal refrigerated conditions (2-8 degrees Celsius/ 36-46 degrees Fahrenheit) for at least 6 months and administered within existing healthcare settings. The Pfizer vaccine supply requires they stay at a temperature of -70 degrees Celsius.
Vaccinations are expected to begin next week, according to Soriot.