why the government is promoting a different second dose for AstraZeneca

While in Argentina the need to administer vaccines against the coronavirus with doses from different laboratories has been highlighted due to the shortage of the second component of Sputnik V, the initiative of the combined schemes includes an additional option, of which little and nothing has been said so far: the Oxford “cross”.AstraZeneca with Moderna.

You could call it the “Merkel Formula», Alluding to the German Chancellor, who was encouraged almost before everyone to this combination, at the end of June.

Thus, many in Europe put their bodies at the service of stratagems heterologous against Covid, especially in the midst of the media alarmism of certain cases of thromboembolism, after the injection of the vaccine developed in Oxford. However, the combination that was subsequently appealed was AstraZeneca with Pfizer.

But, since Pfizer and Moderna were “cousins” (both from the United States, both on a messenger RNA platform), it was logical to assume (as Merkel did) that the result of the two acting as a “booster” (strengthening) of AstraZeneca would be more or less similar.

The question is now important especially in Argentina. The government not only encourages those who started their program with the Russian vaccine to supplement it with Astra or Moderna, but also, that those who started with AstraZeneca can complete with Moderna.

Cases

They are more than 5.7 million of people who have the first dose of AstraZeneca and, therefore, they would be candidates to combine with a second dose of Moderna.

The data comes from the Nation’s Ministry of Health. Concretely, as of Monday, 8,496,298 people had received at least one dose of the English vaccine (or its version developed in India, the Covishield vaccine). Of these, 2,730,864 have already completed the program, while the 68% would need the second dose.

Why is there a push to combine AstraZeneca? Is there a concern about a missing dose, as happened with Sputnik?

Since Friday, some jurisdictions they described it: They believed (especially in the city of Buenos Aires) that there would be a “bump” in vaccine delivery this week. Those of AstraZeneca, in particular, would not arrive until mid-August, they feared.

However, the arrival of other 204,100 doses from this lab, a small number compared to other deliveries.

We must not forget the context: the authorities are awaiting the administration of second doses in the face of what they consider to be an imminent wave (the extent of which no one can predict, for the moment) by the Delta variant, whose severe effects are only manageable complete immunization schedules.

By analyzing the number of doses of those 200,000 that each jurisdiction in Argentina would have, and considering, once again, the race against delta, it is logical that the Government favors the combination of doses from different laboratories, in what could be summed up as a fingerprint of “All with all”.

But, for this “cross” to bear fruit in this case of a pandemic, new games from Moderna should arrive, which Joe Biden’s government has not ruled out, after sending 3.5 million doses, that the Argentine government takes full advantage to vaccinate those under 18 with risk factors and complete the missing Sputnik.

Scientific support

Although the government confirmed a few days ago that the tandem of AstraZeneca and Moderna is safe and efficient (They did not disclose specific data; the ad was “attached” to data of Sputnik’s combination with other brands), the health ministries of the city and province of Buenos Aires confirmed to Bugle that for now they do not offer this heterologous option, mainly because “until now it was not necessary”.

But, leaving out the thrombi and not counting the bumps in the deliveries, betting on the combination of AstraZeneca with Moderna may have other compelling reasons.

The first concerns the efficiency. Several studies offer promising results on the combination of the Oxford and Pfizer vaccines. And Moderna, as said, is a very similar vaccine.

For information specific to the Astra / Moderna combination, the New England Journal of Medicine (NEJM) published a letter to the editor of Swedish scientists in mid-July, entitled “Heterologous vaccination ChAdOx1 nCoV-19 and mRNA-1273”.

As explained at Clarin Daniela Hozbor, “Vaccinologist” at the Institute of Biotechnology and Molecular Biology (IBBM) and professor at the UNLP, “these patterns generate a more robust response even for the more difficult variants to induce protection, such as the beta variant ”(“ ex ”South Africa).

The authors of the report also assure that Moderna would be a great option as a third dose for those who have received the full AstraZeneca schematic.

The second issue for which the promotion of heterologous vaccination (outside the Russian world) makes sense, is the time.

The better the laboratory pooling data, the easier it will be to inflate the scope of vaccination, which is now moving faster but started too slowly in the country. In the face of a potential advance from Delta (or any variant, in the future), new safe and effective combinations will give more plasticity to any campaign.

PS