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The UK government’s case for implementing mandatory Covid-19 vaccinations for NHS staff in England has failed to address how the health service will cope when thousands of staff leave their jobs as a result, a report has warned.
A new report, published by the House of Lords Secondary Legislation Scrutiny Committee, has ruled that the government’s evidence for the move was “broad-brush” and “superficial”.
As the report published in the British Medical Journal explains:
It is widely accepted that randomised controlled trials are the only means of providing robust data on the efficacy of medical interventions because observational data is subject to uncontrolled biases. Yet the randomised trials of the covid vaccines lasted for a very short time and were only powered to provide definitive statistical evidence on preventing ‘symptomatic infections’, not on preventing infection per se, hospitalisation or death. The trials also provided no data on whether the vaccines reduce transmission or not—things we have had to learn the hard way, through real world evidence like the rapid spread of the Delta and now Omicron variants.
Results from the randomised vaccine trials published so far suggested the vaccines were effective in reducing symptomatic infections for a few weeks. The average duration of follow-up for people in the first report from the Pfizer trial, on which licensing was based, was only 46 days, for example. [1] The recent report on data from people who had been in the trial for up to 6 months revealed that the mean total duration of follow-up for the primary outcome of the double-blind trial was 3.6 months for those who received the vaccine and 3.5 months for those allocated to placebo. [2] Moreover, only 7% of participants actually remained in the double blind trial for 6 months. [3] Real-world data are not consistent with the trial results, with high case numbers in doubly vaccinated individuals reported from the UK [4] and Israel [5], for example. This suggests either that effects of vaccines wear off quickly, and/or that some bias crept into original trial procedures, possibly due to unblinding caused by vaccine reactions [6] or other procedural irregularities. [7] The same observational data suggests the vaccines may reduce hospital admission and death due to covid infection, but, in the absence of data from randomised trials it is difficult to be certain, since unknown factors may bias the data in either direction.
More alarmingly, third and fourth ‘booster’ shots have not been tested in any randomised trials, and other data on the efficacy and safety of administering further doses are scanty.
In other words, data on the only outcome properly tested in randomised trials, the prevention of cases by two vaccinations, appear unreliable, possibly due to rapidly waning effects or other factors, and other outcomes and procedures have not been investigated in randomised trials, meaning there is no secure evidence either way.
source bmj.com
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