:quality(80)/cloudfront-us-east-1.images.arcpublishing.com/lanacionar/IDOM4DH2DVCEDHK22FTCHEATEM.jpg "Against the flu: the new generation of sustainable and antiallergic vaccines that are offered for the first time in the country")
In Argentina, last week began the flu vaccination in the middle of a premature and steep rise in H3N2 influenza cases. But the early rise in the number of infections was not the only news. This year, for the first time at the local level, vaccinations against influenza developed from the cell Culture Technology, In addition to the classic ones that are produced from embryonated eggs.
This difference, far from being a mere technicality, has great Benefitsas explained by the specialists consulted by THE NATION. For example, it is no longer necessary to use and then dispose of millions of chicken eggs to make vaccines. In addition, they claim that it improves the effectiveness because it avoids the so-called “adaptation to the egg”, which occurs when the replication of the virus inside the egg generates modifications that lead to less coincidence between the strains circulating and that contained in the vaccine.
“With the old technology of embryonated eggs, which has been used for 80 years, one egg is used for each vaccine. This means that the production of vaccines demands millions and millions of eggs around the world that must have certain production characteristics to avoid contamination. Clearly, we must move towards a model of vaccine production more sustainable”He argues Enrique Casanueva Martinezinfectologist and advisor to the Pediatric Infectology Service of the Southern Hospital.
For the influenza vaccination campaign, the State delivers the trivalent vaccines made in egg This year the Ministry of Health of the Nation acquired 9,600,000 units against the flu, which required the same number of eggs for its production. While the private sector offers the tetravalenteswhich not only provide protection against two variants of the influenza Abut they add protection against two lineages of the flu B.
Daniela Hozbor, group director at VacSal Laboratory of the National University of La Plata and principal investigator of Conicet, explains that once the strains to be used have been defined, the viruses are injected into fertilized chicken eggs and incubated for several days for the viruses to replicate. The virus-containing fluid is then harvested from the eggs, and in the case of inactivated vaccines against influenza, the viruses in the vaccine are inactivated and the antigen purify.
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The specialist points out that in this type of culture the virus can present some mutations to be able to adapt and reproduce better, and thus not be so similar to circulating variants, contrary to what happens with cell culture variants that achieve a antigenic similarity of almost 100%.
For the production of cell technology vaccines, the influenza virus is taken and replicated in animal cells (mammals). “Specific cells are used that allow the virus to reproduce. They are easier to produce, that would represent a great advantage in the middle of a pandemic because it would be easier to scale its production”, indicates Casanova Martinez.
“There are many vaccines that are made in cell culture lines. Some years ago it began to be done with the influenza virus and this type of vaccine is already applied in several countries of Europe and in United States. The virus that is taken as a candidate is the one that World Health Organization It is anticipated that it will be the one with the greatest circulation, and this candidate virus replicates in cells of animal origin,” he details. Pablo BonvehiHead of Infectious Diseases Cemic and member of the Vaccine Commission of the Argentine Society of Infectology.
“Cell line vaccines can be to stock for longer and it is easier to increase your production. But, in addition, those from embryonated eggs sometimes show certain mutations that make the virus not exactly the circulating virus, and it was seen that this difference has a greater impact with the virus A H3N2, which is the one currently circulating. Although, of course, that does not mean that the egg vaccines are not useful, but the use of these new vaccines may become more widespread, ”adds Bonvehí.
In the world, many who are allergic to egg prefer not to get vaccinated against the flu. Although, according to Casanueva Martínez, it must be a “very proven” allergy to have a contraindication absolutely to be vaccinated, with cell culture technology that problem would disappear.
“This type of allergy is an infrequent event, but within the infrequency it occurs more in children. That would no longer be a problem with cell line vaccines”, concludes Bonvehí.
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