July 24, 2024

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mRNA COVID-19 vaccine may not be so perfect as imaged

mRNA COVID-19 vaccine may not be so perfect as imaged



mRNA COVID-19 vaccine may not be so perfect as imaged.  The mRNA vaccine has been plagued with negatives recently. You must understand these truths!


Although mRNA can become a fast and flexible vaccine platform. Starting from the gene sequence, mRNA vaccines can be produced within a few weeks. At the same time, it is unique in its protection against the new coronavirus, but its possible potential side effects-myocarditis cannot be ignored. .

Before the outbreak of the COVID-19 epidemic, mRNA vaccines were not well-known to the world. After all, no country has approved mRNA vaccines, but mRNA vaccines have become famous through the COVID-19 epidemic.


The short development cycle of mRNA vaccines enables rapid development of new candidate vaccines, giving it unique advantages in dealing with ever-changing viruses.


Therefore, mRNA vaccines are getting closer and closer to us, but how much do we know about mRNA vaccines?

mRNA COVID-19 vaccine may not be so perfect as imaged




Excellent data protection?

Danish Epidemiology took the lead in reporting the role of Pfizer vaccination in the real world in February. After vaccinating more than 40,000 people, the vaccine has 95% protection against symptomatic COVID-19; among them, it has 90% protection for medical workers.


This result provided confidence for vaccination; subsequently, more data emerged. In May 2021, Israel’s national vaccination campaign showed that Pfizer vaccine is also 95% protective against new coronavirus infection after the second dose.


So, what is the preventive effect of mRNA vaccines against mutant strains?


The World Health Organization (WHO) has now identified 4 mutants as key mutants, and renamed the main mutants, in order: the British mutant B.1.1.7 is called Alpha, and the South African mutant B.1.351 It is Beta, the Brazilian mutant P.1 is Gamma, and the second-generation Indian mutant B.1.617.2 is Delta.


Many scholars have summarized these mutant strains: India mutant strain B.1.617.2 spreads fastest, followed by the British mutant strain; South Africa mutant strain B.1.351 escaped the most significant immune response, followed by the Indian mutant strain and Brazil mutation Strain.


In the face of complex and changing viruses, the world can’t help but worry about whether mRNA vaccines will fail these mutant strains.


In May 2021, researchers in Qatar reported that after fully vaccinated with Pfizer, the protection against the Beta mutant strain (B.1.351, South Africa mutant) is 75%, and it almost completely prevents severe infections in infected persons. This result is gratifying, because the current results show that the South African mutant strain is the most severe mutant strain that escaped vaccination.


Another serious mutant strain, the second-generation mutant strain B.1.617.2 (Delta mutant strain) in India, has become the mainstream strain that has once again aggravated the epidemic in the United Kingdom. After full vaccination, Pfizer vaccine prevents infection by the symptomatic Delta mutant strain. The protection power is 88%.


Therefore, whether it is protection or in response to the new coronavirus mutant strain, the performance of mRNA vaccines is not unsatisfactory.




Suspenseful side effects

There is no doubt that there is no 100% safe vaccine. The most serious side effect of the nCOVID-19 vaccine is a severe allergic reaction. Based on previous data, the risk of allergic reactions from any vaccination is estimated to be 1 in 1 million doses.


However, recent reports have kept the side effects that may be related to mRNA vaccines on the news and exposed to the world.


According to Greek media reports, Papafanjiru, a member of the Health Expert Committee who advised the Greek government on the prevention and control of the epidemic, said on June 15 that Greece has recorded about 25 to 27 cases of myocarditis after vaccinations with the mRNA COVID-19 vaccine, but currently It is not clear whether the cause of these cases is related to vaccination.


According to the report, Papavanjiru pointed out that the people with myocarditis symptoms after the mRNA vaccination in Greece are mainly elderly people, but in Israel, the people with myocarditis symptoms after vaccination mainly involve young people between 18 and 24 years old.


On June 1, the news section of “Science” magazine compiled reports from the drug inspection agencies of Israel, the United States and the European Union, showing that after the mRNA COVID-19 vaccination, the risk of developing myocarditis in young people increased by 5-25 times.


However, the myocarditis cases reported in Greece this time are mainly elderly people, which can’t help but make the whole world nervous. Fortunately, the symptoms of myocarditis are relatively mild, and most of them only need corticosteroid treatment to fully recover.


As for why the side effects of myocarditis occur, scientists have not yet reached a conclusion. It is speculated that there is a possibility that, in rare cases, the very high levels of antibodies produced in the human body may cause an immune overreaction that causes an inflammatory response in the heart.


Therefore, scientists suggest that according to the Israeli report, 90% of mRNA vaccine-related myocarditis cases are men, basically young people aged 16-30. People vaccinated with mRNA vaccines should be especially wary of chest pain or other symptoms after vaccination, especially after the second dose of vaccination; if they feel unwell, they need to see a doctor in time.




Protection rate may not so perfect

The two mRNA vaccines of Pfizer and Moderna have demonstrated an efficiency of over 90%, which has pushed the development of mRNA COVID-19 vaccines to a climax. However, the performance of another Curevac COVID-19 vaccine candidate in the “mRNA Big Three” has been to a certain extent. This mRNA is hot and poured with cold water.


On June 16, local time, Curevac announced on the company’s official website the results of the second interim analysis of the first-generation COVID-19 mRNA candidate vaccine CVnCoV made in the international key phase 2b/3 HERALD study, showing that this vaccine is effective in preventing symptomatic COVID-19 The effectiveness is only 47%.


Why is it also an mRNA vaccine, Curevac’s CVnCoV is almost half as effective as Pfizer and Moderna vaccines? Judging from Curevac’s press release, this may be related to the rapid mutation of the COVID-19 virus strain.


However, judging from the previously published data of Pfizer vaccine against mutant strains, the excellent response ability to prevent infection of symptomatic Delta mutant strains is 88%. Therefore, it is untenable that the rapid mutation of the COVID-19  virus strain leads to a sharp drop in the effective rate of CVnCoV.


In fact, the disappointment of CVnCoV seems to be a sign. In November 2020, Curevac announced the Phase 1 clinical results of CVnCoV, showing that the neutralizing antibody titers induced by the vaccine were lower than those of Pfizer and Moderna.


The reason why CVnCoV has attracted much attention is not only because there are two mRNA vaccines on the market and showing amazing effectiveness, but also because compared with the previous two vaccines, the vaccine can be stored stably at 5°C and maintain its activity for a long time. Up to 3 months, stored at room temperature for 24 hours, it has unparalleled advantages in transportation and storage. It is undoubtedly a pity that the results of this interim analysis did not meet expectations.


Of course, this regret also hits the mRNA vaccine mythology from the side. After all, as a new vaccine, it is not so mature and its success rate is not so perfect.



Although mRNA can become a fast and flexible vaccine platform. Starting from the gene sequence, mRNA vaccines can be produced within a few weeks. At the same time, it is unique in its protection against the new coronavirus, but its possible potential side effects-myocarditis cannot be ignored. .


In addition, as a new technology, not every manufacturer can achieve that perfection.


(source:internet, reference only)

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