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Faced with outbreaks of coronavirus, some European countries are considering changing the patch and joining the UK to vaccinate as many people as possible with a single dose rather than the two used in clinical trials to date.
This issue has been going on since 30 December, when the UK announced that it would delay the second dose by up to 12 weeks when it approved the Oxford / AstraZeneca vaccine for emergency use. The switch also applied to the BioNTech / Pfizer stand.
Just this week, Denmark announced it would delay the second dose of both Pfizer and the upcoming Moderna jabs by up to six weeks. The German Ministry of Health has also confirmed that it intends to achieve an increase in vaccine coverage with similar delays between doses.
Meanwhile, the U.S. federal government is in talks with Moderna to halve the recommended dose of the vaccine to speed up immunization efforts.
Scientists are divided. Some say the delay could cause additional viral mutations and make the shot ineffective. Others question whether recipients remain more vulnerable, pointing out that allowing larger gaps between doses has not been properly tested.
According to the Late Party camp, an immediate level of broader, if slightly weaker, protection is better than providing stronger protection for half as many people. British Deputy CEO Jonathan Van-Tam pushed that point in Mail on Sunday, saying maximum coverage with the first dose “saved lives”.
Belgium’s best epidemiologist, Pierre Van Damme, also supports the idea of paused dosing. Speaking to broadcaster VRT last week, he said the strategy would quickly provide protection for more people and “the stock’s immunity would grow much faster”. (Belgian Health Minister Frank Vandenbroucke asked the vaccine working group to look into the possibility of a delay between doses, but has not yet made a statement, his spokesman warned that there was still not enough evidence to move.)
With the displacement of vaccine stockpiles and new versions of the British and South African coronaviruses that are causing an alarm – complemented by overburdened health systems – some politicians are now standing by the latter camp.
The catch: Although the UK approach has been developed and supported by a number of public health scientists, it lacks the rigor of the tests tested, the UK is so skilled.
Not fully tested
Former Prime Minister Tony Blair raised the idea in early November of vaccinating as many people as possible with the Oxford / AstraZeneca vaccine before it was approved for emergency use. Doctors and scientists quickly rejected it on the grounds that it would roughly reach the controls that are already underway for these treatments. Such studies eventually screen out therapeutic winners (dexamethasone) from the losers (hydroxychloroquine).
The controversy shifted further this week as the British Immunology Society tilted its hand on Monday. While their statement “attached the utmost importance to an evidence-based approach to medical decisions”, they call for a “pragmatic approach” in the short term given the “unprecedented situation”. The Company has backed the delayed two-dose schedule – provided the government develops a “robust immune control program.”
Sheila Bird, former program manager at the MRC Biostatistics Unit at the University of Cambridge, went one step further. In a statement sent by e-mail on Monday, it called on the UK to randomize standard and delayed dosing schedules to compare the effectiveness of both approaches.
“Trials would be good for these versions, although the data available to us show very good protection against a single dose of AstraZeneca or Pfizer. [vaccines]… The speed and breadth of vaccination is crucial to success, ”said John Bell, a professor at Oxford University who is also a member of the UK Vaccination Task Force.
Details of a shot
In the United Kingdom, chief physicians in favor of delayed doses pointed to data showing that the effectiveness of the short-term vaccine from the first dose with the BioNTech / Pfizer vaccine was about 90 percent and with the Oxford / AstraZeneca vaccine about 70 percent. The second dose is likely to be “very important for the duration of protection,” they said in a joint letter dated 31 December.
However, some scientists remain concerned that the effectiveness of the second dose of Pfizer and AstraZeneca vaccines may exceed the indicated three- and four-week periods, respectively.
For example, data from the British Immunology Society for the BioNTech / Pfizer vaccine show that antibodies and T cells are more effectively neutralized after the second dose. Society also notes that “similarly, the Oxford / AstraZeneca vaccine shows significant immunological differences after a second dose of 28 days.”
However, it was concluded that delaying the second dose by eight weeks “is unlikely to have a negative effect on the overall immune response after shock”.
Peter English, former editor of Vaccines in Practice magazine and former chairman of the Public Health Medical Committee of the British Medical Association, was also in delays. In a writing from Monday, he wrote that decades of experience with other vaccinations show that, if there is one, “increasing the interval improves the quality of the reminder response”.
Do you receive an approved single dose?
As Johnson & Johnson is investigating the issue in a large clinical trial, more data on the efficacy of a single dose and the duration of protection by the end of the month are likely to emerge.
Like Oxford / AstraZeneca jab, the J&J vaccine is based on adenovirus virus vector technology. It uses a modified cold virus to transmit information to cells and prompts them to make the spike protein antigen to build an immune response.
Following the successful approval and introduction of the Ebola vaccine, J&J, who has experience with epidemic vaccination, said in November that while the single-dose vaccine would have “significant benefits, especially in pandemic conditions,” the company’s vaccination program was administered in two separate studies.
Unpublished early results from a first-stage clinical trial showed that a single dose could effectively produce sufficient antibodies in 98 percent of patients after 29 days, the company said.
Until positive results are achieved, the U.S. pharmaceutical company plans to submit global licenses with data to support a single-dose schedule. The European Medicines Agency hopes to reach a decision in March.
The UK approach allows for the unauthorized use of both Pfizer and AstraZeneca vaccines, which means that these jabs can be administered without consequence, outside their authorized indications. This is possible due to the instructions of the Joint Vaccination and Vaccination Committee, which provides protection against retaliation.
The same is not true elsewhere in Europe, where countries will use EMA-approved vaccines.
“I don’t think healthcare professionals … in the EU would support or otherwise be inclined to promote any use outside the label,” said Vincenzo Salvatore, a lawyer at Bonellei Erede and a former EMA consultant.
“Any change to: [administration] would require a variation to the marketing authorization, “the EMA said, as reported by Reuters,” and additional clinical data are needed to support such a change. Otherwise, it can be considered as off-label use. “
Vaccine manufacturers have also protected clinically approved indications.
“Our Phase 3 clinical trial and U.S. emergency use license is associated with 100 doses in two doses, 28 days apart,” a Moderna spokesman said in an email about half-doses in the United States.
BioNTech echoed this feeling in FT, reiterating that no data were available to support the administration of two doses of the vaccine after 21 days.
English, who is also a consultant in controlling communicable diseases in the UK, said the vaccine committee had the advantage of “looking at the population and needs around”. It contains decades of knowledge about vaccines, the immune system and their interactions – “not just on the basis of attempts to get a license”.
He also warned of the fatal risk of limiting the factors that influence these decisions.
“People are divided into those who want explicit, narrow, direct empirical evidence, and those who are willing to extrapolate from circumstantial evidence,” he said. “The issue is that lives can be lost if we wait for the tight direct evidence.”
Charlie Cooper, Hans von der Burchard and Camille Gijs contributed to the report.
This article is part of the following section: POLITICOpremium insurance service: Pro Health Care. Among other things, our journalists, who specialize in drug prices, the EMA, vaccines, medicines, and more, are constantly monitoring the topics that drive the health policy agenda. E-mail [email protected] for a free trial.