What they look like, how they protect us and what 4 side effects of COVID-19 vaccines produce

Despite the different technologies used to obtain COVID-19 vaccines, all four are approved by the two largest independent bodies (US and Europe) showed high efficacy, well above the 50% required by the WHO as an approval limit.

Everything went so fast that three questions arise that a new document attempts to answer based on the publications and press releases of the producing companies, as well as reports from the two regulatory agencies: the United States Food and Drug Administration. (FDA) in the United States and the European Medicines Agency (EMA) in Europe.

The FDA has approved vaccines produced by the companies Pfizer / Biontech, Moderna and Johnson and Johnson / Janssen for administration in the United States, which are expected to be approved by the EMA soon.

For its part, the EMA has authorized the Pfizer / Biontech, Moderna and AstraZeneca / Oxford vaccines. All of them have passed clinical trials involving tens of thousands of people and some are administered en masse to the general public.

To obtain approval from regulatory agencies, theVaccine companies must conduct clinical trials involving tens of thousands of people. The four companies carried out these trials in different countries, with different age groups and at different times during the pandemic. Does it matter? Yes, especially since in recent months variants of the virus have appeared which can be transmitted more easily and even partially escape the immune response.

In all cases, after the phase III trials were completed, each vaccine was assigned a percentage of effectiveness, an approximation of how it protected the volunteers who received the vaccine versus those who received the vaccine. a placebo. The efficacy of the two vaccines whose clinical trials were conducted later (AstraZeneca / Oxford and J & J / Janssen), in the presence of new viral variants, is lower. Therefore, it is difficult to compare the effectiveness of the four vaccines.

Another important difference concerns the age group. Clinical trials of the AstraZeneca / Oxford vaccine have included so few people over 65 that its effectiveness in this segment of the population cannot be judged. That is why in many countries it is only given to young people.

The most serious side effects

Relevant aspects that give an idea of ​​the other benefits of vaccines should also be analyzed in clinical trials. In general, vaccines should reduce the number of people infected, the number of cases of serious illness, the degree of severity and hospitalization, and the number of deaths. A summary of the data extracted from the clinical trials is presented in the following table.

The reduction in cases of serious illness after the application of the vaccine is very important. Also that of admissions and deaths in ICUs, although, as indicated in a recent article, there are very few cases in both the placebo group and the vaccinated group.

In all four vaccines, the adverse reactions reported in clinical trials are very similar and do not differ substantially from those seen for vaccines given from birth.. Some differences are observed depending on the intensity, which can be mild or moderate, but they always disappear after two days with the usual prescription pain relievers. No severe reaction was observed in any vaccine.

Allergic reactions have been observed which, being extremely rare, are classified as “of unknown frequency”. These, fortunately, have postponed after rapid interventions. For this reason, it is recommended that you rest and remain alert for 15 to 30 minutes after administration.

But the study of the side effects of vaccines doesn’t stop once they’re approved. Surveillance aims to detect any effect on the vaccination process. The third AEMPS pharmacovigilance report has already been published, in which no undescribed side effects have been reported for approved vaccines, despite millions of doses having already been administered.

Once vaccines have been approved by regulatory agencies, street-level studies begin to find out how well the vaccine works. It is no longer compared between vaccine and placebo, but between vaccinated and unvaccinated people.

Although it is still too early to know these results, there is already some very encouraging data. Much of this data comes from Israel, a country that has entered into an agreement with Pfizer / Biontech to gain access to its vaccine in exchange for information on the incidence of the disease during vaccination campaigns.. Well, in Israel hospitalizations and deaths among the population over 65 have already stopped abruptly. Therefore, it seems that the effectiveness of the vaccine will be very similar to its effectiveness, that is, more than 90%. And the same can be expected from the other three vaccines.

For comparison, the influenza vaccine, which is administered overwhelmingly each year, has an effectiveness of between 40 and 60%.

These four vaccines are already known to be safe and effective. It is hoped that many more will achieve the goal which will result in improvements, such as eliminating transmission of the virus or adapting quickly to new variants.

What seems indisputable is that today, as a society, the challenge seems to immunize the population as soon as possible with these four vaccines and those that are approved. Stopping the pandemic is essential.

It is not easy to compare the effectiveness of these vaccines, but we know that it is much superior to that of other vaccines administered routinely, such as influenza. And yes, you can compare the side effects. These are similar and in the vast majority of cases (if they occur) go away within 24 to 48 hours, eased with pain relievers. As are the vaccines routinely given to babies.

KEEP READING: