The extremely rapid development of COVID-19 vaccines deeply influenced public opinion. Between the identification of SARS-CoV-2 in early 2020 and the first vaccination campaigns in Europe at the end of the same year, less than one year had passed. An unprecedented speed in the recent history of medicines and vaccines.
For many people, this rapid timeline increased mistrust toward COVID-19 vaccines: were some development stages shortened? Were safety evaluations skipped? Did European health authorities take excessive risks?
In reality, the situation is far more nuanced. Vaccines were indeed developed through accelerated procedures in Europe, but this does not mean that clinical trials or scientific evaluations disappeared.
COVID-19 vaccines: A technology already under development before the pandemic
One of the most common misconceptions about these vaccines is that mRNA vaccines were created from scratch within a few months.
However, research on mRNA technologies had already been ongoing for decades. Scientists had notably continued working on coronaviruses after the SARS and MERS epidemics. When the genetic sequence of SARS-CoV-2 was published in early 2020, pharmaceutical companies already had advanced technological platforms available for future vaccines.
This existing scientific groundwork significantly accelerated the first development phases.
Accelerated clinical trials, but not removed
Contrary to some claims circulated during the pandemic, the traditional clinical trial phases for COVID-19 vaccines were carried out:
- Phase I to evaluate safety,
- Phase II to determine dosage and immune response,
- Phase III to demonstrate efficacy on tens of thousands of participants.
What changed was the organization of these phases. Several stages were conducted in parallel rather than sequentially.
Under normal circumstances, pharmaceutical companies generally wait for the full completion of one phase before launching the next one or investing massively in industrial production. During the COVID-19 crisis, vaccine manufacturers started producing millions of doses before receiving marketing authorization.
This approach represented a major financial risk, but it reduced development timelines by several months.
The key role of the EMA “rolling review”
The most important regulatory acceleration for COVID-19 vaccines in Europe was probably the implementation of the “rolling review” procedure by the European Medicines Agency (EMA).
In a standard procedure, pharmaceutical companies submit a complete regulatory dossier only after all data are available. Regulatory authorities then begin the scientific assessment.
European experts evaluated the data as soon as they became available: preclinical data, manufacturing quality data, early clinical trial results, and production information. (ema.europa.eu)
This rolling review process dramatically reduced administrative timelines while maintaining scientific assessment standards.
The EMA started the rolling review of the Pfizer-BioNTech COVID-19 vaccine in October 2020, even before the official marketing authorization application was submitted.
Conditional marketing authorization for COVID-19 vaccines
The first COVID-19 vaccines obtained a conditional marketing authorization (conditional MA) in Europe.
This procedure already existed within European pharmaceutical regulations for emergency situations or unmet medical needs. It allows faster access to medicines and vaccines when the expected benefits outweigh identified risks, while imposing additional obligations on pharmaceutical companies after authorization.
In practice, the evaluation of COVID-19 vaccines did not stop after authorization:
- continuation of clinical trials,
- regular submission of additional data,
- reinforced pharmacovigilance,
- continuous reassessment of the benefit-risk balance.
The EMA also emphasized that conditional authorization for COVID-19 vaccines remained subject to the usual European standards of quality, safety, and efficacy.
Unprecedented pharmacovigilance for COVID-19 vaccines
The monitoring of adverse events linked to COVID-19 vaccines was also exceptionally reinforced.
With hundreds of millions of doses administered within months, pharmacovigilance systems rapidly detected several rare safety signals, including:
- myocarditis associated with mRNA COVID-19 vaccines,
- atypical thrombosis observed with some viral vector vaccines.
These signals led to rapid updates of recommendations and package leaflets.
This intensive monitoring was sometimes perceived as evidence that COVID-19 vaccines had initially been insufficiently tested. Yet it also demonstrated the capacity of European pharmacovigilance systems to detect extremely rare adverse effects that could not realistically be identified during conventional clinical trials.
Why COVID-19 vaccines still fuel mistrust today
Several years after the pandemic, the rapid development of COVID-19 vaccines still contributes to mistrust among part of the population.
This mistrust is partly linked to a poor understanding of European regulatory mechanisms. Many people only remember that COVID-19 vaccines were developed “in less than a year” without understanding:
- the rolling review procedure,
- massive public funding,
- pre-existing vaccine technologies,
- or conditional marketing authorization mechanisms.
The pandemic was also marked by sometimes contradictory communication from political leaders and health authorities in an unprecedented emergency context.
Ultimately, COVID-19 vaccines were not authorized without evaluation. Europe implemented exceptional regulatory procedures to accelerate access to vaccines while maintaining a high level of scientific oversight.
Sources
- European Medicines Agency (EMA) – Conditional marketing authorisation
- European Medicines Agency (EMA) – COVID-19 vaccines: development, evaluation, approval and monitoring
- European Commission – Safe COVID-19 vaccines for Europeans
