Intended for healthcare professionals

CCBY Open access

Rapid response to:

Research

Risk of thrombocytopenia and thromboembolism after covid-19 vaccination and SARS-CoV-2 positive testing: self-controlled case series study

BMJ 2021; 374 doi: https://doi.org/10.1136/bmj.n1931 (Published 27 August 2021) Cite this as: BMJ 2021;374:n1931

Linked Editorial

Strengthening international surveillance of vaccine safety

Rapid Response:

Cases of “SARS-CoV2 infection” refer to the same vaccinated population.

Dear Editor,

the article by Hippisley-Cox et al. states that the cases of “SARS-CoV2 infection” refer to the same vaccinated population. Cf. ibd.

“We also investigated the association between a SARS-CoV-2 positive test and the thrombotic events of interest among the same vaccinated population.”

and

“Table 1: Baseline demographic characteristics of people receiving first dose of covid-19 vaccine or testing positive for SARS-CoV-2 virus among vaccinated population in England from 1 December 2020 to 24 April 2021”

The same can be read on the picture on Dr. Hippisley-Cox’s twitter account, “...who went on to catch COVID-19”, see https://twitter.com/JuliaHCox/status/1431141982555058176

As I read it the “SARS-CoV2 infection” cases were vaccinated. Hippisley-Cox et al. should clarify this point.

Best regards,
Johannes Kreis

Competing interests: No competing interests

28 August 2021
Johannes Kreis
Researcher
Frankfurt