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Unity is strength: in times of Covid it also applies to vaccinations. In addition to the “race” that dozens of companies around the world are doing, each in their own way, to develop the best product to block the virus, there is also a case that does not happen often: AstraZeneca and Sputnik V have decided to join forces and mix their vaccines.
The AstraZeneca Note
British-Swedish biopharmaceutical company AstraZeneca said it will test its Covid vaccine in combination with the Russian after some Russian scientists suggested last month that combining the two preparations could increase their effectiveness. To find out more, we tried to get in touch with the respective companies: Moscow-based Gamaleya Institute never responded, AstraZeneca sent us a note emphasizing how, to “overcome the COVID-19 pandemic, more than one will be needed vaccine and, since several vaccines are being tested and / or approved, it is important to understand how they can be used, their interchangeability or their improvement. Being able to combine different vaccines can be useful to improve protection and / or access to vaccines and for this It is therefore important to explore different combinations to help make immunization schedules more flexible, allowing physicians more options at the time of administration. “
Union also with other vaccines ”. AstraZeneca’s note ends with a reflection that paves the way to “evaluate combinations heterologist of different vaccines, working with industrial partners, governments and research institutes around the world, and will soon begin to collaborate with the Gamaleya Research Institute in Russia to understand whether two adenovirus-based vaccines can be combined successfully. ” In practice, it is not excluded that there may also be a union with vaccines from other companies. Kirill Dmitriev, director of the Russian sovereign wealth fund RDIF (Russian Fund for Direct Investments) that financed Sputnik V, said “the strength of Sputnik V technology and our willingness and desire to partner with other vaccines to fight Covid together“, as reported by the Delivery courier.
How do they work
The tests will begin in days, they are expected by the end of the year. But what do the two anti-Covid vaccines have in common? Meanwhile, the Italian-English developed by AstraZeneca together with the Irmb company from Pomezia, called AZD1222, has been shown to be 62.1% effective when administered in two full doses but the efficacy increases up to 90% in volunteers. who received a half dose followed by a full dose. This is what emerged from the interim analysis of phase three studies, published in the Lancet. In the vaccine a type of vector Non-replicative virus that uses a harmless virus to stimulate the recipient’s immune system to develop antibodies. Compared to the mRNA vaccines from Pfizer and Moderna, the AstraZeneca injection is easier and cheaper to manufacture, transport and store (refrigerated between 5 and 8 degrees). Italy is betting a lot on this vaccine: it has bought 40.38 million doses, only surpassed by those of the Johnson & Johnson company with 53.84 million (click here to consult the complete table)
Here’s Sputnik V. Like the Oxford-Pomezia vaccine, the Russian Sputnik V is also based on a modified version ofadenovirus, a common cold virus. This “vector” is stripped of all disease-causing genes and modified to carry the genetic instructions for making the coronavirus protein, which is passed into human cells. The spike protein produced by the coronavirus triggers an immune response that protects against Covid-19 disease.
The AstraZeneca mistake
What if the association was born because one or both vaccines did not demonstrate the desired efficacy? More than legitimate doubt, since AstraZenenca suffered a strong stop due to an error in the DoseIn fact, the volunteers were given only half a dose, which surprisingly turned out to be more effective than the full one (two full doses 62% effective, half dose plus 90%). “I don’t know, I think they are business logics that involve, if anything, the regulatory agencies and some States. What is likely is that, since the technological platform is very similar, they have thought of a synergistic alliance for production, period. “he said exclusively for ilgiornale.it Professor Massimo Clementi, Director of the Microbiology and Virology Laboratory of the San Raffaele Hospital in Milan, who explained the difficulties of the Italian-English vaccine.
“Very serious error”. “AstraZeneca started very fast, then they met in a big way difficulty due to the dosage error, a very serious error for a pharmaceutical industry, which is to halve the dose. There are several theories as to why it happened, perhaps a detector did not work well but it is something that should not happen, “explained Clementi. Italy, as explained above, has focused a lot on this vaccine that, at the moment, does not give the guarantees of other pharmaceutical companies. “If the data is what we have seen, apart from 90% of the dose in half, 70% was what was considered acceptable as minimum efficacy but, at present, it is considerably lower than that of Pfizer and Moderna, more 90%. I think, therefore, that there is some kind of difficulty, “the professor told us. However, in addition to the vaccine, the British company has developed a study antibodies monoclonal as prophylaxis against infections. “It seems very good to me, not all subjects will respond to vaccines, a small proportion will not respond or will not be able to be vaccinated. Having an alternative is always a good thing, ”says Clementi.
Anti-vector immunity
One potential problem with this type of vaccine relates to “anti-vector immunity”: if the immune system has previously encountered the type of adenovirus used in the vaccine, it can destroy it before the vaccine can trigger an immune response. This is why the Oxford University team chose to use a chimpanzee adenovirus rather than a human one. However, anti-vector immunity could also reduce the effectiveness of booster vaccines, if this involves injecting the same virus a second or third time. Therefore, mixing and matching different vaccines could provide a solution. This concept is known as ‘heterologous primary enhancement’ and has been used in vaccination programs against other diseases.
Differences from mRNA vaccines. “Adenovirus is a vector inert, its only task is to carry the RNA it carries into cells: many adenoviruses, however, are widespread in the human species and choosing a human one could be risky because it could elicit an antibody response against the vector that prevented the vaccine to enter cells, ”explained Clementi. That is why a primate vector was chosen, in this case a monkey. “This problem does not exist with vaccines. mRna which are transported by small particles of lipids, fats, which enter cells and are totally inert ”.
Any doubts. Unlike AstraZeneca, Sputnik V uses two different vectors of adenovirus humans to try to trigger a stronger and long-term immune response. It is not yet clear which of these components will be tested in conjunction with the AstraZeneca vaccine. As reported by the The Guardian, anti-vector immunity could also provide a possible explanation for why the AstraZeneca vaccine appears to work better when given as a half dose followed by a full, rather than two full doses.
What is the current situation
The vaccine developed by Oxford and the Italian company Irbm de Pomezia, despite the abrupt stop, is already in phase three and in the coming days ahead from the UK Medicines Agency for use in the English population. In the first weeks of 2021 it could also be validated for Italy if Ema and Aifa are okay. On the other hand, however, the Russians began the administration of their Sputnik V as early as December 10, despite much perplexity from the scientific world over the haste with which it was approved and the lack of sufficient data for the ok. definitive (we talked about it in InsideOver). In recent hours, however, the Russian Ministry of Health has also authorized people over 60 years of age for mass vaccination. Health Minister Mikhail Murashko stressed that the latest analysis confirmed that the use of Sputnik V “does not present any risk to the elderly“.
