COVID-19 (COrona VIrus Disease-2019) Тема - 7

Thrombo-embolic events with concurrent low platelets
Up to 28 April 2021, the MHRA had received Yellow Card reports of 242 cases of major thromboembolic events (blood clots) with concurrent thrombocytopenia (low platelet counts) in the UK following vaccination with COVID-19 Vaccine AstraZeneca. These events occurred in 141 women and 100 men aged from 18 to 93 years and the overall case fatality rate was 20% with 49 deaths. Six cases have been reported after a second dose .

Cerebral venous sinus thrombosis was reported in 93 cases (average age 47 years) and 149 had other major thromboembolic events (average age 55 years) with concurrent thrombocytopenia.

The estimated number of first doses of COVID-19 Vaccine AstraZeneca administered in the UK by 28 April was 22.6 million and the estimated number of second doses was 5.9 million.

The overall incidence of case reports of thromboembolic events with low platelets after first or unknown doses was 10.5 per million doses.

Taking into account the different numbers of patients vaccinated with COVID-19 Vaccine AstraZeneca in different age groups, the data shows that there is a higher reported incidence rate in the younger adult age groups compared to the older groups. The MHRA advises that this evolving evidence should be taken into account when considering the use of the vaccine. There is now some evidence that the reported incidence rate is higher in females compared to men although this is not seen across all age groups and the difference remains small.

These reports have also been analysed by the Government’s independent advisory body, the COVID-19 Vaccines Benefit Risk Expert Working Group, which includes lay representatives and advice from leading haematologists.

On the basis of this ongoing review, the advice remains that the benefits of the vaccine outweigh the risks in the majority of people.

Table 4: Number of suspected thrombo-embolic events with concurrent thrombocytopenia ADR reports received for the Oxford University/AstraZeneca vaccine in the UK up to and including 28 April 2021
Country   Number of reports
England   198
Wales   9
Northern Ireland   5
Scotland   18
Unknown   12
Table 5: Number of UK suspected thrombo-embolic events with concurrent thrombocytopenia ADR reports received for the COVID-19 Vaccine AstraZeneca by patient age up to and including 28 April 2021.
Age range (years)   Number of reports   Number of fatal reports
18-29                                           24                               6
30-39                                           31                               8
40-49                                           38                               7
50-59                                           68                             15
60-69                                           36                               8
70-79                                           25                              4
80-89                                            5                              1
90-99                                            1                              0
Unknown                                  14                              0
Total                                          242                           49
Table 6: Number of UK suspected thrombo-embolic events with concurrent thrombocytopenia ADR reports received for the Oxford University/AstraZeneca vaccineCOVID-19 Vaccine AstraZeneca by patient sex up to and including 28 April 2021.
Sex   Number of reports   Number of fatal reports
Male                 100                         17
Female                 141                         32
Unknown            1                           0
Total                  242                          49
To note, direct comparison of the summary provided here and the analysis prints is not possible. This is because this summary includes reports of CVST or other thrombo-embolic events with concurrent thrombocytopenia. Yellow Card reports may contain more than one reported reaction and the analysis prints are listed by individual reactions rather than whole reports. Therefore, summing the reactions listed in the prints will not equate to the total cases included within this summary.