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In the face of coronavirus issues, some European countries are considering whether they should change tack and enter the UK in vaccinating as many people with just one dose as opposed to both. which has been administered during clinical trials to date.
This case has been alive since December 30, when the UK announced its decision to delay second doses for up to 12 weeks when it approved the Oxford / AstraZeneca vaccine for use in urgent. The version also involved BioNTech / Pfizer injection.
Just this week, Denmark announced its decision to delay the upcoming second dose of the Pfizer and Moderna jobs by up to six weeks. The German health ministry has also confirmed to look at expanding vaccine coverage with similar delays between doses.
Meanwhile, the U.S. federal government is in talks with Moderna about halving the proposed dose of the picture to accelerate vaccination efforts.
Scientists are divided. Some argue that viral mutations could be delayed and that the bullet would be ineffective. Others question whether recipients will be left more vulnerable, indicating that larger dose intervals have not been properly tested.
The pro-delay camp argues that an immediate, if slightly weaker, level of protection is better than providing a stronger defense in half as many people. UK Deputy Chief Medical Officer Jonathan Van-Tam reiterated this point in the Mail on Sunday, saying that increasing coverage with the first dose will “save lives. “
Belgian epidemiologist Pierre Van Damme also supports the idea of stop dosing. Speaking to broadcaster VRT last week, he said the strategy would provide more protection to more people quickly, and “herd protection would grow at a much faster rate.” (Belgian Health Minister Frank Vandenbroucke has asked the vaccine action group to investigate the possibility of a delay between doses, but has not yet reported, with his spokesman warning that there is insufficient evidence still for the move.)
With vaccine supply squeezed and new UK and South African coronavirus changes trigger warnings – exacerbated by overweight health systems – some politicians are now in favor of that latter camp .
The catch: While the UK approach has been developed and supported by many public health scientists, it is not as rigorous in controlled trials as the UK is so familiar with.
Not fully tested
The idea of vaccinating as many people as possible with the Oxford / AstraZeneca vaccine was first approved for emergency use by former Prime Minister Tony Blair in early November. It was abruptly rejected by doctors and scientists because it would run roughshod over controlled clinical trials that had already begun for these treatments. Such studies ultimately excluded therapeutic agents (dexamethasone) from detoxifiers (hydroxychloroquine).
The debate moved later this week when the British Society of Immunology dropped its hand on Monday. While their statement placed “the greatest value on an evidence-based approach to medical decision-making”, they called for a “pragmatic short-term approach” with the “unprecedented situation . “The Association supported the two-dose delay program – as long as the government developed a” robust program of immunization monitoring. “
Sheila Bird, who was director of the program at Cambridge University’s MRC Biology Unit, went a step further. In a statement on Monday, she called on the UK to set standard timelines and random delays to compare the effectiveness of the two approaches.
“Testing for these changes would be good, although our data show very good protection from a single dose of AstraZeneca or Pfizer. [vaccines]… The speed and breadth of the vaccine is crucial for success, “Dr John Bell of Oxford University, who is also a member of the UK vaccine action group, said in an email.
One picture data
In their defense of delaying doses, top UK medical officials cited data showing that the short-term efficacy of a vaccine from the first dose is around 90 per cent with the BioNTech / Pfizer vaccine and around 70 per cent with the Oxford / AstraZeneca vaccine. The second dose appears to be “very important for the duration of the defense,” they said in a joint letter dated 31 December.
Some scientists are concerned, however, as to whether efficacy may decline beyond the three- and four-week indicated for second doses of the Pfizer and AstraZeneca vaccines respectively.
Data from the British Society of Immunology on the BioNTech / Pfizer vaccine, for example, show that antibodies and T cells are more effectively neutralized after the second dose. The association also states that “similarly, the Oxford / AstraZeneca vaccine shows significant immunological differences after the second dose at 28 days.”
They concluded, however, that a delay in a second dose by eight weeks would be “unlikely to adversely affect the overall immune response after an increase.”
Peter English, former editor of Vaccines in Practice magazine and chairman of the British Medical Association’s Public Health Medicine Committee, explained the delay. In an op-ed from Monday, he wrote that decades of experience with other vaccines have shown, if at all, “increasing the time contributes to increasing the response quality.”
One allowed dose coming?
With Johnson & Johnson examining the issue in a large clinical trial, more data on single-dose efficacy and duration of protection are likely to arrive by the end of the month.
Similar to the Oxford / AstraZeneca injection, the J&J vaccine is based on adenovirus viral vector technology. This uses a modified cold virus to carry information into the cells, telling them to spike the protein antigen to build an immune response.
J&J, which has experience of pandemic vaccination following the licensing and launch of its Ebola vaccine, said in November that a single-dose vaccine would have “significant benefits, especially in the case of pandemics,” a program the company’s vaccine also tested two doses in a separate trial.
Unpublished early results from an initial clinical trial showed that a single dose is effective in generating sufficient antibodies in 98 percent of patients after 29 days, the company said.
Pending positive results, the U.S. drug dealer plans to file for global licenses with data supporting the one-dose schedule. The European Medicines Agency hopes to reach a decision in March.
Final visit
The UK approach allows off-label use of both Pfizer and AstraZeneca vaccines, meaning that these jobs can be delivered outside the permitted mark without side effects. This is possible because of guidance from the Joint Committee on Vaccination and Vaccination, which provides protection against retaliation.
The same does not apply elsewhere in Europe, where countries use EMA-licensed vaccines.
“I don’t think healthcare professionals … in the EU would enforce or otherwise encourage any form of off-label use,” said Vincenzo Salvatore, a lawyer at Bonellei Erede and former senior adviser to the EMA.
“Any change to [administration] a change in marketing authority would be needed, ”the EMA said, as reported by Reuters,“ as well as more clinical data to support such a change. Or it would be considered ‘off-label use.’ “
Vaccine manufacturers have also protected clinically approved symptoms.
“Our Level 3 clinical trial and U.S. Emergency Use Authorization are related to 100ug at two doses, 28 days apart,” a Moderna spokesperson said in an email, on the topic of half-doses in the U.S.
BioNTech accepted this view in the FT, reiterating that there is no data to support the administration of two doses of the vaccine given more than 21 days apart.
English, who is also a consultant in infectious disease control in the UK, said the vaccine committee’s benefit was that it “sees the population and the needs in the tour.” It covers decades of knowledge of vaccines, the immune system and how they interact – “not just according to tests carried out to obtain the consent. ”
He also warned of the fatal risk of limiting the factors influencing those decisions.
“People are divided into those who want clear, narrow, direct empirical evidence and those who are willing to introduce extrapolation from indirect evidence,” he said. life could be lost if we wait for the narrow direct evidence. “
Charlie Cooper, Hans von der Burchard and Camille Gijs reported.
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