Dispute between health organisations: administration of the second dose of the COVID-19 vaccine in Catalonia after the temporary suspension of the adenovirus vaccine (Preprint)
Authors: Fuster-Casanovas Aïna , Vidal-Alaball Josep , Velasco-Márquez Eduard , Bonet-Esteve Anna , Miró Catalina Queralt 
Published: March 2023

BACKGROUND

On 16 March 2021, the Spanish Agency of Medicines and Medical Devices (AEMPS) issued an informative note regarding the temporary suspension of vaccination with the adenovirus vaccine (Vaxzevria® by AstraZeneca) against COVID-19 to study a possible causal relationship with cases of cerebral venous thrombosis. Once the pertinent evaluation was carried out, the Public Health Commission recommended to the Interterritorial Council of the National Health System (CISNS) to end the vaccination schedule with the mRNA vaccine (Comirnaty® by Pfizer-BioNTech). It is worth mentioning that while the CISNS recommended the second dose with the mRNA vaccine, the European Medicines Agency (EMA) and the World Health Organisation (WHO) recommended the adenovirus vaccine.

OBJECTIVE

It is relevant to study whether the population has followed the recommendations of the CISNS. If not, the channels from which they extracted the information and the determinants that have led the population to reject the mRNA vaccine were ascertained.

METHODS

Cross-sectional descriptive study using an ad-hoc self-administered questionnaire. The sample was for convenience, which included all users under 60 years of age who went to the population vaccination points of El Bages, Berguedà, Osona and Anoia between the months of May and July 2021 to complete the schedule initiated with the adenovirus vaccine.
The reading of the answers to the questionnaires was carried out with the Teleform v16.5 software. The statistical analyses were performed with version 3.6.3 of the statistical program R.

RESULTS

Of 4,344 people who responded to the survey, 94.9% decided to receive the second dose of adenovirus vaccine (Vaxzevria® by AstraZeneca). 93.7% of those who received the second dose of adenovirus vaccine consulted prior information, compared with 88.6% of those who received the second dose of mRNA (Comirnaty® by Pfizer-BioNTech).
The sources of information consulted with a significant link with the decision have been official websites, and consultation with health professionals and co-workers.
Regarding the answers obtained on the main reason for deciding on the second dose of adenovirus, not mixing vaccines (42.2%), the recommendations of health professionals and/or the evidence of scientific studies (24.1%) and own beliefs (22.1%), were the reasons for decision mentioned most.

CONCLUSIONS

The vast majority have opted for the homologous regimen (first and second doses with the same type of vaccine) without following state recommendations. Signing an informed consent form in the middle of a vaccination schedule is unusual. The dispute between the health organisations should not have affected the population in the form of decision-making responsibility, however, they opted for the homologous regimen following the indications of the EMA and the WHO.

CLINICALTRIAL

The study protocol was approved by the University Institute for Primary Care Research (IDIAP) Jordi Gol Health Care Ethics Committee (Code 21/235-P).