Study: Serious Adverse Events of Special Interest Following mRNA Vaccination in Randomized...

A NEW paper by BMJ Editor Dr Peter Doshi and colleagues has analysed data from the Pfizer and Moderna Covid vaccine trials and found that the vaccines are more likely to put you in hospital with a serious adverse event than keep you out by protecting you from Covid.

The pre-print (not yet peer-reviewed) focuses on serious adverse events highlighted in a WHO-endorsed ‘priority list of potential adverse events relevant to COVID-19 vaccines’. The authors evaluated these serious adverse events of special interest as observed in ‘phase III randomised trials of mRNA COVID-19 vaccines’.

A serious adverse event was defined as per the trial protocols as an adverse event that results in any of the following conditions:

  • death;

  • life-threatening at the time of the event;

  • inpatient hospitalisation or prolongation of existing hospitalisation;

  • persistent or significant disability/incapacity;

  • a congenital anomaly/birth defect;

  • medically important event, based on medical judgement.

Dr Doshi and colleagues found that the Pfizer and Moderna mRNA COVID-19 vaccines were associated with an increased risk of serious adverse events of special interest of 10.1 events per 10,000 vaccinated for Pfizer and 15.1 events per 10,000 for Moderna (95 per cent CI -0.4 to 20.6 and -3.6 to 33.8, respectively). When combined, the mRNA vaccines were associated with a risk increase of serious adverse events of special interest of 12.5 per 10,000 vaccinated (95 per cent CI 2.1 to 22.9).

The authors note that this level of increased risk post-vaccine is greater than the risk reduction for Covid-19 hospitalisation in both Pfizer and Moderna trials, which was 2.3 per 10,000 participants for Pfizer and 6.4 per 10,000 for Moderna. This means that on this measure, the Pfizer vaccine results in a net increase in serious adverse events of 7.8 per 10,000 vaccinated and the Moderna vaccine of 8.7 per 10,000 vaccinated.

Addressing the difference between their findings and those of the FDA when it approved the vaccines, the authors note that the FDA’s analysis of serious adverse events ‘included thousands of additional participants with very little follow-up, of which the large majority had only received one dose’. The FDA also counted ‘people affected’ rather than individual events, despite there being twice as many individuals in the vaccine group than in the placebo group who experienced multiple serious adverse events.

The authors wonder where the U.S. Government’s own studies of adverse events are. They note that in July 2021, the FDA reported detecting four potential adverse events of interest following Pfizer vaccination – pulmonary embolism, acute myocardial infarction, immune thrombocytopenia and disseminated intravascular coagulation – and stated it would further investigate the findings. However, no update has yet appeared.

They also note that ‘while CDC published a protocol in early 2021 for using proportional reporting ratios for signal detection in the VAERS database, the agency has not yet reported such a study’.

The authors point out their results are compatible with a recent pre-print analysis of Covid-19 vaccine trials by Benn et al, which found ‘no evidence of a reduction in overall mortality in the mRNA vaccine trials’, with 31 deaths in the vaccine arms versus 30 deaths in the placebo arms (3 per cent increase; 95 per cent CI 0.63 to 1.71).

Noting their study is limited by the fact that the raw data from Covid-19 vaccine clinical trials are not publicly available, they stress that ‘given the global public health implications, there is an urgency to make all Covid-19 trial data public, particularly regarding serious adverse events, without any further delay’.

They conclude that there is a need for formal harm-benefit analyses for Covid vaccines, taking into account the different levels of risk of serious Covid and adverse events that exist between demographic groups. Ideally, this would be based on individual participant data, they say, though such data remain frustratingly unavailable.


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