Scant amount of side effect of all vaccines against COVID-19
All side effects to the three vaccines used in Europe were announced today
The COVID-19 Vaccines
A public discussion on the processes of approval and monitoring of the safety of vaccines against COVID-19 in the EU was held today, March 26, 2021. The online event was organized and hosted by the European Medicines Agency (EMA) with the assistance of experts from the European Center for Disease Control (ECDC). Members of the group Science in the Crisis – Dr. Momchil Baev and Simeon Petrov also took part.
The main topics of discussion were the vaccines – already approved and pending approval, their safety, and efficacy, monitoring side effects, reviewing preliminary data from the widespread use of vaccines in some countries such as Israel, testing vaccines in children, and adapting new doses of vaccines to coronavirus variants.
It has been found that so far all approved vaccines have a positive benefit-risk balance, and the differences in efficacy data are largely due to the criteria and methodologies of the various clinical trials.
In terms of safety and side effects, most of the observed and reported data are of mild to moderate severity and are temporary.
In some rare cases (1/100 000) severe allergic reactions (anaphylaxis) have been observed and with an even lower frequency of manifestation are the so-called thromboembolic events, which have been observed in approximately 30 / 10,000,000 vaccinated.
The Eudra Vigilance system for reporting adverse reactions within the European Union collects information submitted by EU citizens and healthcare professionals. Most of the reported adverse reactions are among those already mentioned in the Summary of Product Characteristics (SPC) of available vaccines. Many different institutions and circles, including citizens, are involved in the process of monitoring the safety of vaccines. Here we present the interaction between all these factors:
From the beginning of the administration of the approved vaccines on the territory of the EU, comprehensive statistics show the number of administered doses alongside the percentage of adverse reactions of each vaccine:
- 94,303 cases of side effects have been reported with 42 million doses of COMIRNATY (Pfizer / BioNTech). These are only 0.22% of the side effects of all doses given.
- At 2.6 million doses of Moderna Covid Vaccine - 4550. These are only 0.17% of the side effects of all doses.
- At 9.2 million doses of ChAdOx1-S (AstraZeneca / OxfordUniversity) - 28,042. These are only 0.3% of the side effects of all administered doses.
EMA has performed a comprehensive analysis for thromboembolic events and thrombocytopenia associated with the free mentioned above vaccines. During the analysis, were used already established techniques :
- Detailed clinical examination of cases registered by citizens and medical personnel
- Statistical methods for identifying emergency values and models for the presence of side effects in the population.
- Comparison between data for EXPECTED and OBSERVED events and effects.
The EMA is currently conducting an ongoing review of clinical trial data from several manufacturers. Data of the Novavax vaccine is undergoing review by the EMA since the 3rd of February 2021; data of the CureVac vaccine – since the 12th of February, and data of the Sputnik V vaccine – since the 4th of March this year.
Given the rapidly spreading false claims that the regime for the approval, testing, and administration of vaccines is hasty and it has compromised security, we draw attention to this procedure of the European regulator.
Continuous monitoring of the impact of new SARS-COV2 variants on vaccine efficacy is needed. Additional studies will be performed to compare the efficacy between people immunized with doses of the initially developed vaccines and people vaccinated with doses of latter adapted vaccines to the new variants. So far, sufficient information is available that vaccines offer protection against severe illness caused by the British version (B.1.1.7). Protection against a moderate illness against the South African variant can vary considerably depending on the vaccine therefore, more data is required. No information is available on the effect on the Brazilian version P.1.
Clinical trials will be conducted on the use of COVID-19 vaccines in children and adolescents by manufacturers of all vaccines approved to this date. Some have already begun this process.
There are still unanswered questions for the medical community and regulators. Several important topics that excite the population in our country and in Europe are in the process of research:
- Are 2 doses required for people with a history of COVID-19 or is 1 dose sufficient? (Jannsen vaccine is initially given as a single dose)
- What should the optimal intervals between the doses be?
- Is it possible to increase immunity with different vaccines? There is still not enough clinical evidence, but EMA looks forward to seeing if the data can be generated in this regard.
- Use of vaccines in immunocompromised patients. There are already fragmentary data from various studies on this issue, but the European and Bulgarian regulators have not yet adopted them as their position.
