What changes between Chinese and Western vaccines?

There are those who have begun to distribute the first doses and those who are waiting to receive them. The countdown to managing vaccinations the anti coronavirus has started. Between the second half of December and the month of January, many countries plan to inject the antidote at least into the categories of people most at risk, such as the elderly and health workers, only to pass it on to the rest of the population.

As we know, there will not be just a ready-to-use vaccine. The list of drugs capable of defeating Sars-CoV-2, by contrast, is full of candidates. As the New York TimesResearchers around the world are currently testing 59 vaccines in human clinical trials. Of these, 16 reached the final testing stages. From this point of view, it is important to underline how the vaccination effort of the China is following a very different course than the one underway in U.S and in Europe. The reason is simple: the main western vaccines (a term by which, for convenience, we consider both vaccines produced in Europe and in the US) are based on a different scientific workings than the Chinese (or Russian) candidates.

Different vaccines

Simplifying as much as possible, we can say that each vaccine is based on different technologies. We find, for example, rna-DNA vaccines. These are based on fragments of genetic material produced in the laboratory, which are called to encode a part of the coronavirus, such as the spike protein used by the aforementioned virus to infect human cells and reproduce in the body. In other words, once the human body has received such vaccines, it follows the instructions of the dna-rna copy the coded part of the virus, recognize it and activate an immune response.

The candidate of Pfizer-Biontech uses the technology just explained (so far has never been used to develop an approved vaccine). Since the messenger RNA molecule is fragile and our enzymes would destroy it, scientists have enveloped it in an oily bubble made up of lipid nanoparticles. This explains why such vaccines must be transported and stored at a temperature of -70 ° C (Modern vaccine is satisfied with a temperature of -4 ° C).

Chinese serums, by contrast, have been based on a much more traditional form: that of inactivated virus, an approach that dates back to the first flu vaccine of the 1930s. In other words, the major Chinese vaccines (certainly those from Sinopharm and Sinovac) contain heat-, chemical-, or radiation-treated viruses, so these pathogens they can trigger an immune response but cannot replicate. CanSino, like AstraZeneca, embraces instead adenovirus 5 (Ad5), that is, viruses responsible for a common cold that, once modified and rendered harmless, are used to carry genes in the body of the pathogen from which immunity is sought.

Advantages and disadvantages

Depending on the technologies used, each vaccine will have advantages and disadvantages logistic. As noted by the South China morning post, experts believe that sera that use inactivated and vectorized viruses, such as CanSino and AstraZeneca from China, will have short-term benefits such as raw material The necessary installation will not represent a problem as long as the production plants are operational in their respective hubs. On the other hand, mRna vaccines could face some initial problems in the supply of raw materials but, in the long run, they could be easier to obtain. mass produce.

Jerome Kim, CEO of the International Vaccine Institute (IVI), explained that the raw materials of established technologies are less of concern because they use common lines. “Adenoviruses are easy to grow. We do not expect there to be a problem with the supply chain. Instead, there are concerns about mRNA vaccines and their ability to increase production. In fact, there is not much experience in the use of this technology ”, he concluded. We will see what will happen once the various vaccination campaigns begin.