A group of researchers from CINTESIS – Center for Health Technology and Services Research and the Faculty of Medicine of the University of Porto (FMUP) warns that it is urgent to accelerate the reporting of adverse reactions to COVID-19 vaccines.

In a study published in the International Journal of Clinical Pharmacy, the scientists warn that during a pandemic, surveillance of adverse drug reactions (ADRs) should be “more active” and information should be provided “in real-time” to support the decisions of health authorities.

They, therefore, appeal to hospital emergency rooms and other urgent care services for the need to report “immediately” any suspected adverse reaction to vaccines.

“The need for permanent knowledge about vaccines is an absolute priority. The traditional model, based mainly on spontaneous notifications (passive pharmacovigilance), is not adequate to the current context,” say the FMUP/CINTESIS researchers, who are also part of the Porto Pharmacovigilance Unit (UFPorto).

In the first half of 2021 alone, the UFPorto received 2248 spontaneous notifications of suspected adverse reactions, of which 2121 are related to COVID-19 vaccines. These numbers are considerably higher than the number of suspected ADRs in the same period of previous years (536 in 2019 and 234 in 2020).

As they explain, “most of the ADRs reported nationally fit the profile common to any vaccine, which includes injection site reactions or systemic reactions such as fever, headache or muscle pain. These reactions have been described in clinical trials and disappear within hours or days, without the need for medical intervention and without sequelae.

However, many doubts and questions remain, such as what is the risk of adverse reactions to the vaccine in patients who have had COVID-19, how severe is the infection in vaccinated patients, or in case of adverse reactions at the first dose, what is the risk of recurrence and what are the recommendations for the second dose.

The researchers recommend implementing several measures, including developing active pharmacovigilance programs, intensifying monitoring of the most vulnerable populations (namely pregnant women, children, and adolescents, the elderly, immunocompromised individuals, or those with a history of allergies), conducting awareness campaigns, and enhancing communication with healthcare professionals, patients, and institutions.

In addition, they say that “it is urgent to provide the units with more logistical and human resources that can advance campaigns to raise awareness among the population and professionals of the need for notification, but to fill the necessary resources to process the increased information.”

Renato Ferreira da Silva (FMUP/CINTESIS/UFPorto) is the first author of this study, carried out in co-authorship with Inês Ribeiro Vaz (FMUP/CINTESIS/UFPorto), Manuela Morato (LAQV/REQUIMTE) and Jorge Polónia (FMUP/CINTESIS and coordinator of UFPorto).