Short-term Effect of COVID-19 Vaccine on Blood Pressure

Safety of coronavirus disease 19 (COVID-19) vaccines has been a concern. Despite safety
profile of different vaccines demonstrated in phase 2/3 trials, there has been evolving
evidence on adverse effects of some particular COVID-19 vaccines. One of the mostly known
example is vaccine-induced thrombotic thrombocytopenia (VITT). Apart from the thrombotic
risk of ChAdOx1 nCoV-19 vaccine, there has been studies providing the preliminary data on
effect of mRNA-based COVID-19 vaccine on blood pressure.

A case series report was published on Hypertension in June 2021 on documented stage III
hypertension within minutes of vaccination (mRNA vaccines) in a vaccination centre
located in Switzerland. The study reported 9 subjects experienced a surge in blood
pressure to stage III hypertension after vaccination. Yet the study had a few
shortcomings. There was not baseline measurement of blood pressure. Surge of blood
pressure shortly after vaccination could be due to nervousness or white coat effect. Thus
surge of blood pressure within minutes of vaccination could be not due to vaccination.
There was not long-term follow-up on blood pressure measurement after vaccination.

Further to the case series report, another prospective study in Italy investigated effect
of mRNA vaccine on blood pressure and heart rate. The study was conducted as a survey.
There was 5.3% of respondents (6/113) reported rise of home blood pressure of at least
10mmHg after 1st dose vaccination, compared with home blood pressure prior to
vaccination. Among these subjects, 4 of them required anti-hypertensive medication
intensification.

Yet there remains lack of evidence and detailed description on effect of COVID-19
vaccines and blood pressure before and after vaccination. Use of ambulatory blood
pressure monitoring (ABPM) before and after vaccination helps to understand the details
on short-term blood pressure changes.