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Preliminary results show that more than 90 percent of people will be protected by the Pfizer-BioNTech coronavirus paired vaccine, the two companies announced Monday. Several new types of RNA-based vaccines are also in development, and it looks like Pfizer will be the first. The European Union is signing a contract for the 300 companies for 300 million doses, and in December it can arrive in Hungary from the vaccine. What are RNA vaccines and why are there high expectations for vaccination?
Conventional vaccines often contain attenuated or killed pathogens, possibly fragments of pathogens (proteins). Once in our body, they trigger an immune response, preparing our body to defend itself against a particular virus or bacteria. The problem is that the production of these types of vaccines is difficult: the pathogen must be cultured in a laboratory, which is a particularly difficult task for viruses, since a cellular environment must be provided for their reproduction. The procedure is not only expensive but also time consuming.
Cells do not receive a virus, but a model.
RNA-based vaccines work in a similar way to traditional ones: They stimulate the body to produce antibodies by triggering an immune response. However, there is a very important difference.
RNA vaccines are manufactured by the body to produce viral proteins that then activate the immune system.
This requires the so-called messenger RNA (mRNA). Its operation can be very briefly summarized as follows: mRNA reads from genes which proteins should be produced and then sends the resulting “blueprint” to the protein (ribosome) where the desired product is produced.
Pfizer-BioNTech’s messenger RNA carries the information necessary to assemble one of the vital components of the coronavirus, the spike protein. Researchers wrap messenger RNA in a lipid envelope, and the vaccine actually gives us that. The lipid that carries the mRNA is taken up by our cells and begins to produce spikes in them.
Therefore, the virus protein will be produced by our own cells.
The coronavirus spike alone is not harmful, but it is capable of priming the immune system to fight the pathogen.
Why might an RNA-based vaccine be the main one?
The complete virus is not necessary for the preparation of RNA-based vaccines, in this case it is sufficient to obtain the sequence of the gene that encodes the spike protein.
When the coronavirus first appeared in Wuhan, a team of researchers quickly mapped the pathogen’s gene pool, making the full set of genetic codes soon available to drug manufacturers.
Various companies have been experimenting with RNA vaccine development for some time, so they were able to respond quickly to developments. The genetic model of the virus, which was made available to the public in early 2020, was first obtained by Moderna in the US, followed by CureVac in Germany, and then by BioNTech, also based in Germany. Pfizer works with the latter.
In addition to being faster, easier and cheaper to produce, RNA vaccines are also safer; Since they do not contain the complete gene pool of the virus, they theoretically cannot cause infection, even in the case of a very weak immune system.
Chris Beyrer, a professor at the Johns Hopkins Bloomberg School of Public Health, told Fast Company magazine that although RNA-based vaccines are still very new and will be tested for the first time, researchers are very confident that the peak of the virus can elicit a sustained immune response and support this. research data to date.
How has Pfizer studied the effectiveness of the vaccine?
According to Pfizer, the third phase of clinical trials was carried out in six countries, with a total of 43,538 people. Some of the volunteers received a real vaccine and another received a placebo. The vaccine had to be administered twice, 28 days apart.
According to preliminary data, 94 participants were infected with coronavirus and less than 10% of those vaccinated developed symptoms of COVID-19.
That is, the vaccine protected people with 90 percent effectiveness.
The final phase of clinical trials has not yet been completed, work must continue until 164 infected are found, so the efficacy rate may change or even improve later.
However, the results are already more than promising. According to the regulations of the United States Food and Drug Administration (FDA), a vaccine can be approved if it reduces the development of the disease by at least 50 percent, experts say that the Pfizer vaccine is already far behind. above that threshold.
I don’t even remember the last time there was a 90 percent effective respiratory virus vaccine. ” Drew Weissman, an immunologist at the University of Pennsylvania, told the Afp news agency. Weissmman’s opinion is also authoritative because in the 1990s, in collaboration with the Hungarian biochemist Katalin Karikó, he laid the necessary scientific foundations for the development of RNA vaccines.
In the future, Pfizer-BioNTech researchers will also look at whether the vaccine protects people who have previously received COVID-19 and reduces the severity of symptoms in people who still develop the disease despite receiving the vaccine.
The two companies developing the vaccine have applied for emergency approval for the vaccine. Pfizer expects to be able to deliver 50 million vaccines by the end of 2020 and 1.3 billion by the end of 2021. The European Union has announced the purchase of 300 million doses of the vaccine.
Extremely low temperatures of -80 degrees Celsius will be required for safe storage and a double dose of vaccine will be required due to the two doses required for protection.
And the competitor?
Moderna, which is also experimenting with RNA-based vaccination, has not yet published the results of the third phase of clinical trials. All you know is that the final phase of testing began on July 27, with the participation of 30,000 American volunteers. However, initial reports are encouraging here too: In the first phase of the experiments, antibodies and T cells that appeared to protect against the virus appeared in healthy adults, even the elderly. The company plans to produce 500 million a year from a vaccine called mRNA-1273.
However, at the moment, it appears that Pfizer could be used more widely first. Stéphane Bancel, Moderna’s CEO, said in September that mass vaccination with mRNA-1273 certainly could not start in the first half of 2021.
According to Weissman, if the technology works well now, RNA vaccines to protect against herpes, influenza and HIV pathogens could arrive in a few years.
Pfizer-BioNtech vaccine may arrive in Hungary in December – announced Prime Minister Viktor Orbán in an interview with M1. It can be given first to healthcare workers, law enforcement personnel, and those most at risk. There are also talks about a Russian, Chinese and Israeli vaccine.
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