Coronavirus, because the effectiveness of the Pfizer and Moderna vaccines will also be useful against future pandemics

3 ‘reading

The coronavirus that has kept the entire planet in check for months was taken into account by some unheard of observers. Overpopulation, combined with the push into territories of other animal species, the consumption of forests, the intensification of livestock and a set of other factors, sooner or later favored leak. For any new leaps to humans, or possible changes over time in the SARS-CoV-2 itself, the evidence from testing its products at the most advanced stage is of significant importance. Because if the success of the Pfizer-BioNTech and Moderna trials (plus all the others to follow) is truly confirmed, it implies that potentially we will have a powerful new weapon against future pandemics.

What is the turning point

The reason lies in the ingenious operating mechanism behind both, namely the promising messenger RNA technology. “It is a new class of vaccines made up of an mRNA sequence that encodes a specific protein (antigen). The messenger RNA carried by lipid droplets within the body of the person, produces the peak protein that the virus uses to adhere to human cells and penetrate them “, he summarizes Massimo Ciccozzi, Head of the Research Unit in Medical Statistics and Molecular Epidemiology of the Campus Bio-Medico Universitario. In essence, cells are transformed into factories of substances capable of annihilating the threat of the virus. “This type is safer and has fewer side effects than inactivated virus vaccines. It is easier to produce than traditional ones and does not contain infectious agents. In addition, the manufacturing process is cheaper and faster and, therefore, very useful in the fight against pathogens in full evolution (influenza virus and today the case of SARS-CoV-2) ». In mRNA vaccines, a genetic sequence of an agent-specific antigen can be inserted directly into the body through a carrier which can be lipid droplets or human or chimpanzee adenovirus-like vectors. “This mRNA sequence is then used by the host cell’s synthesis machinery to produce the antigen, the protein and, in the case of SARS-CoV-2, the spike.”

Loading…

The role of neutralizing antibodies

Both in the case of mutations related to Covid-19 and in the appearance of other pathogens, the platform could be ready for use, thanks to the speed and agility that are the two true strengths. Going into more detail, Ciccozzi explains that “the vaccine can stimulate the B lymphocytes that produce antibodies, a subtype of T lymphocytes (CD4 +) or another subtype of lymphocytes (CD8 +, also called CTL). The most promising approach, at least in theory, is to stimulate the production of neutralizing anti-spike antibodies. These prevent the virus from entering the cells of the body: as long as a subject produces neutralizing antibodies, the virus that is deposited on the mucous membranes (for example, the nose) cannot enter the cells and the subject does not become ill.

At what stage is the experimentation?

The SARS-CoV-2 vaccine developed by Pfizer and BioNTech has completed phase 3 trials in 43,500 volunteers, being 95% effective in preventing the onset of symptoms (and therefore the disease), even in the elderly. “The study is based on the analysis of 170 infected people, of which 162 in the group that received a placebo (based on water and salt) and 8 among those vaccinated. Ten people developed severe Covid-19 and only one of them had received the vaccine. Side effects were mild / moderate and resolved quickly. The most serious was fatigue, which affected 3.7 percent of the volunteers after the second dose (taken 3 weeks after the first). ‘

Questions still unanswered

As has been widely announced, supplies will initially be so limited that neither country will be able to emerge from the pandemic at lightning speed. They both need the double dose three weeks apart (Pfizer) or four (Moderna). But one of the big questions refers, also according to the epidemiologist of the Bio-Medico Campus, to distribution logistics. “The Pfizer vaccine should be stored at minus 70-80 degrees. The one produced by Moderna lasts up to 30 days at 4 degrees Celsius, so it would be easier to store and transport than the Pfizer medicine. Same basic “philosophy” but different lipid formulations to contain and protect mRNA. “The ease of transport and storage is certainly an advantage because it would be possible to carry out vaccination in pharmacies, doctors’ offices, wherever there is a normal refrigerator.”
In Italy, for example, “the only two airports certified to receive drugs are Fiumicino and Malpensa, but they are not equipped with refrigerators at temperatures as low as those required by the Pfizer vaccine.” Without neglecting the fact that “the cold chain must be ensured from the moment the drug leaves the place of production until the dose is administered: if it is stored incorrectly, vaccines lose their effectiveness”.