The head of the research: «We are optimistic. If necessary, a large-scale ah-hoc product soon ». That’s why mRNA vaccines update so quickly
If a new vaccine against the Omicron variant of Covid Moderna is needed, it will be able to “produce it on a large scale by the beginning of next year”. This was claimed by the head of researchers of the US company, Paul Burton, according to the Guardian. “We must be confident, we have learned a lot about Covid and how to deal with it,” he said, underlining that “it is a dangerous-looking virus, but now we have many tools in our armory to fight it, so I am optimistic”. Burton explained that a more precise idea of the effectiveness of vaccines against the Omicron variant will be obtained in the “next two weeks”, but if a new vaccine will be needed, “it could be mass-produced by early 2022”.
On the day WHO christened Omicron declaring it a “worrying variant”, Moderna announced that it will develop an anti Covid vaccine booster specifically against the new strain. “We have three lines of defense that run in parallel: a booster with a higher dose (100 mg); two multivalent booster candidates that anticipate mutations such as those emerged in the new variant; a specific candidate (mRna-1273.529) “he reported Stéphane Bancel, chief executive officer dell’azienda Usa.
MRNA vaccines, notably Moderna and Pfizer-BioNTech, have been built with technology that should allow for quick change. Pfizer scientists also said they can “adapt the current vaccine within six weeks and ship the initial batches within 100 days in the event of a variant escaping the current vaccine,” he said. Jerica Pitts, Pfizer spokesperson.
How mRNA vaccines are updated quickly
But how is it possible to update mRNA vaccines in such a short time as the two pharmaceutical companies that produce them have announced? These vaccines can be adapted quickly thanks to the new technology used. If Omicron turns out to be a mutation that greatly reduces the effectiveness of vaccines, it would not be “redone” because it is the use of mRNA that simplifies the changes. In mRNA vaccines, a piece of the code is used, the mRNA, the messenger that carries into cells the information needed to produce the virus spike protein. The goal is to stimulate the immune system’s response against the spike, which is the part with which the virus attaches to cells and spreads throughout the body. In the mRNA vaccine an individual receives the code for producing the protein and not the protein itself (purified) or the attenuated or inactivated virus. Among the advantages of this type of product there is also a greater ease, compared to other vaccine technologies, of change this code in case of mutations. By changing the mRNA carried into the cells, which is used for the production of the spike, the new structure of the protein is reproduced with the mutations, without changing the platform. It is easier to produce and replace mRna, the synthesis of which is chemical rather than biological, than the virus or proteins based on protein vaccines or attenuated or inactivated viruses. A few days after obtaining the genetic code of the variant, it is possible to have an mRNA sample ready for the first vaccination tests.
General tests already in progress
The pharmaceutical companies have actually been working for some time to get ready in case a variant appears very different from the others and capable of “piercing” the vaccines currently on the market. In recent months Pfizer-BioNTech have been carrying out research by practicing on known variants of Sars-CoV-2 such as Beta and Delta; they tested up-to-date vaccines with clinical trials and fine-tuned workflows to be ready to move quickly if and when a new ‘immune escape’ variant really emerges. The two companies tested a specific vaccine against the Beta variant in a randomized, controlled clinical trial involving 930 participants. In August, the companies began testing a multivalent vaccine against Alpha and Delta. “We are not carrying out these tests because we think we need them to combat these strains, but to test all the steps necessary to update the vaccine: from pre-clinical research, to production, to clinical tests up to the presentation of the data to the regulatory bodies in order to be ready and quick to leave in case of need, “he told Nature magazine in October
Philip Dormitzer, vice president and chief scientific officer in Pfizer’s Viral Vaccine Development Department. A sort of dress rehearsal, then. So much so that the pharmaceutical company has stressed or does not intend to market the vaccines created against the Beta and Delta variants.
Moderna also recruited 500 participants to test new vaccines against Beta and Delta and against the two variants together. «The purpose – he had affirmed Jacqueline Miller, senior vice president and head of infectious disease research at Moderna – is to establish a well-established path that could prove useful in the future on strains that may prove more resistant to vaccines ”.
How to determine the effectiveness of vaccines
However, determining the true efficacy of vaccines against a new variant in the real world can be difficult. It may be difficult to find volunteers who have not yet been vaccinated but are willing to experiment with a new product, especially in those areas of the world that have had access to mass vaccination. In addition, ethical problems arise in the recruitment of placebo groups for randomized controlled trials, since effective vaccines are available. For this reason, pharmaceutical companies are working on immunogenicity studies as an alternative to randomized controlled efficacy studies. Immunogenicity studies measure the immune responses triggered by variant vaccines (increased levels of antibodies or B cells) compared to first generation vaccines. And in this case the times are shortened even more.
November 29, 2021 (change November 29, 2021 | 11:48)
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