Pfizer and BioNTech, Moderna, AstraZeneca and Oxford … The most advanced vaccines against Covid 19 are being prepared to request authorization through the emergency route for their distribution and will begin to be supplied throughout December and early 2021.
All have reported high levels of safety, which does not prevent some mild or moderate side effects that generally disappear shortly after delivery.
- BNT162b2 (Pfizer and BioNTech)
The Pfizer and BioNTech vaccine is the leading one among the projects under development to fight Covid 19.
The companies have applied to health regulators in the US for authorization for the emergency use of their vaccine and are expected to receive light. green in mid-December. They also plan to request authorization in the European Union.
Pfizer and BioNTech were the first to announce encouraging results on their vaccine on November 9. According to the companies, the last stage of trials with thousands of volunteers (phase III) has been 95% effective in preventing the disease without major safety risks.
The trials carried out so far have not shown any serious adverse effects , as the companies have highlighted in their statements. Yes there are minor side effects.
The study “has not reported any major safety concerns related to the vaccine,” Pfizer and BioNTech said . Data from a subset of 8,000 participants aged 18 years or older in the phase 2/3 study demonstrates that “the vaccine was well tolerated” and that most adverse effects “resolved shortly after vaccination.”
The only reported Grade 3 (serious) adverse events with a frequency greater than or equal to 2% after the first or second dose were fatigue in 3.8% of cases and headache in 2% after the second dose. Older volunteers tended to report fewer and milder adverse events after vaccination.
The Pfizer and BioNTech vaccine may become the first to use the technology known as RNA . A small sequence of genetic instructions called RNA, created in the laboratory, is injected into the body that “instructs” the body’s cells to produce a specific antigen against the coronavirus.
The advantage is that the vaccine with this technique is easy and fast to produce. Equipment and laboratory requirements are lower. The biggest drawback is that it is necessary to keep it at a temperature below 70 ° below zero to prevent it from losing effect, that is, it needs special cameras for its conservation.
Another condition is the price . The European Commission would have agreed to pay 15.50 euros per dose per vaccine from Pfizer and BioNTech. As the treatment is two doses, the cost rises to 31 euros per treatment.
- mRNA-1273 (Modern)
Moderna’s vaccine is also one of the candidates based on RNA technology. The results of their studies, in which 30,000 people participated in the US, point to an effectiveness rate similar to that of Pfizer and BioNTech, of 94.5%.
In this case, no “significant security problem” was observed , according to the company.
“A review of reported adverse effects indicated that, in general, the vaccine was well tolerated,” he adds. Most of the side effects were “mild or moderate in severity.” Grade 3 (severe) effects with a frequency greater than or equal to 2% after the first dose included pain at the injection site (2.7%), and after the second dose included fatigue (9.7% ), muscle pain (myalgia), in 8.9% of cases; joint pain (arthralgia), in 5.2%; headache (headache) in 4.5%; other unspecified pain (4.1%) and erythema or redness at the injection site (2.0%). Side effects “were generally short-lived.”
Moderna’s vaccine is kept at a temperature of 20º below zero , compared to the 70º below zero required by Pfizer and BioNTech, which is an advantage for its maintenance.
The price is cheaper than that of Pfizer’s vaccine but more expensive than Oxford’s: it will be below 21 euros, but it has not been specified.
Moderna’s vaccine needs a very low storage temperature, although less cold than Pfizer’s
Moderna plans to request authorization from the US for the distribution of its vaccine during these weeks. It also plans to send the petition to the European Union.
- AZD1222 (AstraZeneca and University of Oxford)
AstraZeneca and Oxford have announced that the study carried out in the United Kingdom and Brazil on their vaccine showed that it was very effective in preventing Covid 19, and no hospitalizations or serious cases of the disease were reported in the participants who received the vaccine.
It is effective, on average, in 70% of cases and can achieve protection of up to 90%.
“No serious vaccine-related safety events have been confirmed,” the company said in a statement. AZD1222 was well tolerated “in both dosing regimens”.
Although the definitive data of this vaccine are not yet known, the side effects reported in an earlier phase of the study of this vaccine were similar to those of the previous ones. Fatigue, headache, low-grade fever and myalgia were the most reported systemic adverse reactions, according to The Lancet .
All of them disappeared shortly after administration and the incidence decreased with the second dose. None reported fever (more than 38º).
In September, AstraZeneca and Oxford discontinued clinical trials of their vaccine due to an adverse reaction from a participant. A few days later, the academic institution said it considered it safe to go ahead with the tests.
AZD1222 belongs to the type of non-replicating viral vector vaccines. That is, it was formed from an adenovirus of a type that does not cause disease and is unable to reproduce. Inside it, the genetic code of SARS-CoV-2 was inserted , to provoke a reaction of the immune system.
This vaccine has advantages in its distribution. It is kept at a temperature between 2º and 8º (any refrigerator) compared to the requirements of the Pfizer vaccine (70º below zero) and Moderna (20º below zero if it is stored for more than 30 days).
In addition, the price is much lower than that of Pfizer and Moderna. The AstraZeneca and Oxford vaccine would cost 5.9 euros in total for the two doses, making it by far the cheapest
