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How the Sinopharm Covid-19 vaccine works











At the beginning of 2020, the Beijing Institute of Biological Products has developed an inactivated coronavirus vaccine called BBIBP Company. Later, the Chinese state-owned company Sinopharm put it into clinical trials. Sinopharm announced on December 30 that the efficacy of the vaccine was 79.34%. The vaccine is now in use in Bahrain and the United Arab Emirates. Sinopharm has also applied for approval from the Chinese government.

Vaccine made from coronavirus

The working principle of BBIBP-CorV is to teach the immune system to make antibodies against SARS-CoV-2 coronavirus. Antibodies are attached to viral proteins, such as so-called spike proteins scattered on its surface.







To create BBIBP-CorV, researchers at the Beijing Research Institute obtained three variants of coronavirus from patients in Chinese hospitals. They chose a variant because it can rapidly multiply in monkey kidney cells growing in a bioreactor tank.

Kill the virus

Once the researchers produced the coronavirus in large quantities, they used it with a chemical called β-propiolactone. The compound binds to the coronavirus to inactivate its genes. The inactivated coronavirus can no longer replicate. But their proteins, including spikes, are still intact.







The researchers then extracted the inactivated viruses and mixed them with trace amounts of aluminum-based compound adjuvants. Adjuvants stimulate the immune system to enhance its response to vaccines.

Inactivated viruses have been used for more than a century. Jonas Salk used them to make polio vaccines in the 1950s. They are the base for vaccines against other diseases such as rabies and hepatitis A.

Prompt immune response

Since the coronavirus in BBIBP-CorV has died, they can be injected into the arm without causing Covid-19. Once inside the body, some of the inactivated viruses are swallowed by a type of immune cell called antigen presenting cell.






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Viral protein

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Viral protein

Fragments

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Viral protein

Fragments


The antigen-presenting cells tear the coronavirus and display some fragments of it on its surface. So-called helper T cells can detect this fragment. If the fragment fits one of its surface proteins, T cells will be activated and help recruit other immune cells to respond to the vaccine.

Making antibodies

Another type of immune cells called B cells may also encounter inactivated coronaviruses. The surface proteins of B cells have different shapes, and a few may have the correct shape to lock onto the coronavirus. When the B cell is locked, it can pull part or all of the virus inside and present coronavirus fragments on its surface.

Helper T cells activated against coronavirus can latch onto the same segment. When this happens, B cells will also be activated. It will multiply and pour out antibodies that have the same shape as the protein on its surface.






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Surface protein

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Surface protein

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Surface protein

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Surface protein

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Surface protein

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Surface protein

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Surface protein


Stop virus

After being vaccinated with BBIBP-CorV vaccine, the immune system can respond to live coronavirus infection. B cells produce antibodies that adhere to the invader. Antibodies that target spike proteins can prevent viruses from entering cells. Other kinds of antibodies may block the virus in other ways.


Remember the virus

Sinopharm’s clinical trials have shown that BBIBP-CorV can protect people from Covid-19. But no one can say how long this protection will last. Antibody levels may drop within a few months. But the immune system also contains special cells called memory B cells, which may retain information about the coronavirus for years or even decades.

Vaccine schedule

January 2020 Sinopharm Group began to develop an inactivated vaccine against the coronavirus.

June Researchers report that this vaccine has produced promising results in monkeys. Phase 1/2 clinical trials have shown that the vaccine does not cause any serious side effects and enables people to make antibodies against the coronavirus.



Sinopharm Beijing production plant.Zhang Yuwei/Xinhua, via Associated Press

July The third phase of the trial started in the United Arab Emirates.

August Phase 3 trials started in Morocco and Peru.



Prepare the dosage of the national medicine in Lima, Peru.Ernesto Benavides/AFP

September 14 The UAE urgently approved Sinopharm’s vaccine for use by medical staff. Government officials and others began to accept it.

November The chairman of Sinopharm said that nearly one million people in China have received the Sinopharm vaccine.

November 3 Sheikh Mohammed bin Rashid Maktoum, ruler of Dubai, announced that he had received the vaccine.



Sheikh Mohammed (Sheikh Mohammed) before receiving the vaccine.French Press

December 9 The UAE fully approved BBIBP-CorV and announced its effective rate of 86%. However, the government did not release any details with the announcement, and it is not clear how they came to the conclusion.

December 13 Bahrain has also approved the vaccine.



Sinopharm vaccine vials in the packaging factory.Zhang Yuwei/Xinhua, via Associated Press

December 30 Sinopharm announced that the effective rate of the vaccine was 79.34%. The company has not yet announced the detailed results of its phase 3 trial.


Source: National Center for Biotechnology Information; Science; The Lancet; Lynda Coughlan, University of Maryland School of Medicine; Jenna Guthmiller, University of Chicago.

Tracking the coronavirus





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