Medical staff will receive the Pfizer-Biontech Covid-19 coronavirus vaccine at the Favoriten Clinic in Vienna, Austria, on December 27, 2020, on the occasion of the rollout of the Pfizer-BioNTech Covid-19 coronavirus.
Georg Hochmuth | AFP | Getty Images
The UK’s decision to delay people’s second dose of a coronavirus vaccine is proving controversial, with experts, advisers and the vaccine makers all weighing in on the strategy.
Britain was one of the first countries in the world to launch a massive coronavirus vaccination campaign after approving the Covid-19 vaccine developed by Pfizer and BioNTech in early December. On Monday this week, it started rolling out the vaccine from the University of Oxford and AstraZeneca, after it was approved for use just before the new year.
Since both vaccines require two doses per person, the UK government initially said a second dose would be given three or four weeks after the first dose, depending on the vaccine being given and in accordance with the dosing regimens tested in clinical trials.
However, it now recommends a break of up to 12 weeks, in an effort to give more people a first dose – and some initial protection against Covid-19.
Concerns about vaccine manufacturers
BioNTech and Pfizer have responded to the decision, saying there is no evidence that their vaccine will continue to protect against Covid-19 if the second injection is given more than 21 days after the first dose.
“The Phase 3 study by Pfizer and BioNTech for the COVID-19 vaccine was designed to evaluate the safety and efficacy of the vaccine on a 2-dose schedule separated by 21 days. The safety and efficacy of the vaccine is not Evaluated on a different basis, the majority of the study participants received the second dose within the time frame specified in the study design, ”the companies said in a statement to The Washington City Times Tuesday.
“Although data from the Phase 3 study showed partial protection against the vaccine as early as 12 days after the first dose, there is no data to demonstrate that protection lasts after the first dose after 21 days.”
The companies said it was now “crucial to monitor” alternative dosing schedules.
Final data analysis from the Pfizer / BioNTech clinical studies showed the vaccine to be 95% effective to prevent Covid-19 seven days after the second dose was given.
For the University of Oxford / AstraZeneca candidate, the interim analysis of late-stage study results was slightly more nuanced with an anomaly in the vaccine doses given to subjects. Essentially, when the vaccine was given in two full doses, the efficacy was found to be 62.1%, but when some trial participants were given half a dose followed by a full dose, it turned out to be 90%. For both dosing regimens, the two injections were given one month apart. AstraZeneca was not immediately available for comment on the UK’s decision to delay the second dose.
Reasons behind the decision
The decision to extend the dosage window comes as UK hospitals grapple with increasing admissions. The coronavirus is running amok in the UK with a new, more transmissible strain of the virus that is spreading exponentially in London and the South East, and is now showing up in other parts of the country.
To date, the country has recorded more than 2.6 million coronavirus cases and more than 75,000 related deaths, according to data collected by Johns Hopkins University. On Monday, the United Kingdom registered 58,784 new cases and has now reported more than 50,000 new cases of coronavirus seven days in a row. On Monday, British Prime Minister Boris Johnson announced a third nationwide lockdown for England.
It is against this grim backdrop that the UK regulator of medicines, the Joint Committee on Vaccination and Immunization and the four UK Chief Medical Officers have agreed to slow down the gap between the first and second dose of vaccines in order to ‘get the greatest number of people in the shortest time. “
There are signs that others could follow Britain as well, with Germany’s Ministry of Health now seeking the advice of an independent vaccination committee on whether or not to follow the UK’s dose-delaying tactics. Denmark has reportedly already approved a delay of up to six weeks between the first and second injection of the vaccine.
So far, according to the government, more than a million people in the UK have been vaccinated with the Pfizer / BioNTech vaccine, and some, such as the very first recipient of that vaccine outside of a clinical trial, have received their second dose.
But now thousands of others in the top priority category are now being told to wait up to 12 weeks for their second dose.
The British Medical Association described the move as “extremely unfair” for thousands of at-risk patients in England, but the UK’s independent Scientific Advisory Group on Emergency (SAGE) said in a statement published Sunday that it was a “very difficult and well-balanced decision.”
In response to the BMA’s concerns, SAGE said that “under normal circumstances, we would argue for continuation of the previous plans to administer two doses of the Pfizer-BioNTech vaccine 21 days apart. However, these are not normal conditions. and there are other important health considerations. “
The UK is prioritizing the vaccination of elderly residents in care homes, their carers, people over 80 years old and primary health and social workers.
The country has pre-ordered 40 million doses of the Pfizer / BioNTech vaccine, enough for 20 million people, and has signed a deal with AstraZeneca for 100 million doses, enough for 50 million people. The UK’s population is approximately 66 million.