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Get to know Oxford-Astraseneca Thai vaccines
COVID vaccine – last November A Thai government representative signs a contract to purchase vaccines developed by the University of Oxford. Together with Britain’s AstraZeneca, 26 million doses are enough to inject 13 million people, or about 20 percent of the total population 69 million.
Doctor Nakorn Premsri Director of the National Vaccine Institute In an interview with the Financial Times published on December 19, Thailand’s goal for 2021 is to provide enough vaccines for nearly half of the nation’s population next year. It rose to at least 70 percent by 2022, a proportion of the population who received enough vaccines to cause. ?? Heard Immunity ?? or ?? Moo immunity ?? For preventing the spread of COVID-19 Within the country
ThereThis means just a vaccine from AstraZeneca. Just one company is not enough.
Nakorn doctor confirmed that Thailand is still in negotiations with several vaccine companies. Including manufacturers from China, Russia and India for ?? import ?? Additional vaccines
It is interesting Oxford-AstraZeneca vaccine To be used in Thailand, it is produced by a Thai company, namely Siam Bioscience Under cooperation with Astra Seneca Who are willing to transfer technology in production to
The director of the National Vaccine Institute said. Self-production of the vaccine is considered a ?? National security ?? For one thing, the emerging epidemic is unlikely to be limited to this COVID-19, but it will continue to happen in the future.
Nakorn doctor stated that According to your own understanding Production of the vaccine has begun. The production process to obtain 20 million doses of vaccine takes about 4-5 months. Therefore, the free vaccination process for Thai people. Can start no later than July 2021
But in the midst of another heavy COVID-19 outbreak, In Thailand at the end of the year Mr. Anutin Charnvirakul Deputy Prime Minister and Minister of Public Health Give an interview that The government is preparing to negotiate to purchase vaccines from all manufacturers. To be able to purchase at least 2 million vaccines between February and April. To be able to start the vaccination program at the beginning of the year
So far, however, only Oxford-AstraZeneca’s COVID-19 vaccine has been available. The only one that Thailand can definitely purchase
Recombinant vaccine
The vaccine developed by the University of Oxford. Together with Astra Seneca, the code name is called ?? ChAdOx1 nCoV-19 ?? (Chad Ox One Encovy Nineteen) or the trade name ??Cowi Shield ?? (Covishield) Made with technology ?? Recombinant ?? Familiar Unlike technology ?? MRNA ?? It is used in the production of Pfizer / Bio-Tech and Moderna vaccines, which are brand new. Therefore called as a kind ?? Recombinant vaccine ??
Recombinant technology It is a method for producing vaccines by using modifying (modifying) common viral infections for production. In the case of Oxford, it is ?? adenovirus ?? Which is a common cause of colds in chimpanzees The modifications make the adenovirus weaken. And to contain the genetic material from SARS-COV-2, the COVID-19 virus Included And stimulates the body to build up the immune system to resist or inhibit the spread of infection in the body itself.
One of the advantages of recombinant vaccines is that they are readily produced and produced quickly. Because this is a technology that has been used to produce vaccines for decades. The University of Oxford is currently studying the use of adenovirus to produce vaccines for other diseases. Many diseases already existed when an outbreak of
COVID-19 increases, including development of vaccine against Zika That was previously a severe outbreak in Brazil.
The Oxford University research team started a Phase I human trial in April 2020 by injecting a sample of more than 1,000 volunteers in the UK. This was followed by a phase III human trial involving nearly 24,000 volunteers aged 18 and over in England, Brazil and South Africa.
The results of the third phase human trial that were preliminary results Released at the beginning of December.
On December 30, the Medical Supplies and Health Products Control Office (MHA) of the UK approved the Oxford-AstraZeneca vaccine. Can be injected to the general public This is the second vaccine to be approved in the UK following the Pfizer / Biotech vaccine.
Working process
Recombinant vaccine of Astra Seneca – Oxford Use small parts Of the genes of the SARS-COV-2 virus That is inserted into the adenovirus It is a catalyst for the body’s immune response. The genes used were the only genetic units that the development team needed. Not all of them, so they don’t cause infection.
Heredity of the virus causing COVID-19 That astraZeneca used in the development of the COVID-19 vaccine. At this time it is The part of heredity that is required to produce the protein spike only.
Recombinant vaccine They are generally very safe for use in large populations. Including population groups with chronic health problems Or in groups of people with immune disorders as well
However, recombinant vaccines also have weaknesses. Because periodic booster vaccinations are necessary Same as the pneumococcal vaccine (pneumococcal vaccines), shingles vaccine, and meningococcal vaccine (vaccines for meningococcal disease), etc.
But using adenovirus to produce this vaccine It may also cause problems as well. Because adenovirus is so common that it can cause the immune system to fail to react when stimulated by vaccination. Or have a problem in people who have already had adenoviruses in them
Vaccine efficacy
Oxford – Astra Seneca The effectiveness of the vaccine was tested in the earliest samples between 18 and 55 years of age. In August 2020, the trial was expanded to include subjects aged 55 and over.
Something worth noting is AstraZeneca previously announced the trial in young children. But information about these trials was removed from the company’s website. Without any explanation
The trial was administered by inoculating two samples of vaccines at intervals of one month. The initial trial report of the company stated that The median efficacy of the vaccine from that trial was 70 percent. This mean was calculated from the immunogenicity when administered the first dose, which was 62 percent and 90 percent when the second dose was injected.
After publication of the results Reuters reporter found ?? Discrepancy ?? That occurred during the experiment It was found that the experimental group received different doses of the vaccine. But the discrepancy that arises is the discrepancy that ?? fortunate ?? Because the results showed that When vaccinated with a full dose, the immunity was only 62 percent, but when the vaccine had a half dose, the efficacy increased to 90 percent.
However, the discrepancies that occurred resulted in MHRS Called for further investigation that Caused by accident or intent As a result, the vaccine was approved for use a little later than Pfizer / Biotech vaccine.
Side effects and negative effects
In medicine ?? Side effects ?? (Side effects) are physical reactions to a drug or vaccine, such as arm pain, swelling or redness at the injection site, while the negative effects or adverse reactions (Adverse reactions) are medical symptoms. That arise directly from vaccination
In a preliminary trial published in The Lancet, the Oxford-Astrazeneca vaccine was rated good. But there are a few worrisome negative reactions: one vaccine has had hemolytic anemia. (hemolytic anemia) or ?? anemia caused by the destruction of red blood cells ?? And there are a few more cases who develop symptoms ?? Traverse myelitis ?? (transverse myelitis) or ?? spinal cord condition ?? But the results of the examination in the report confirm that These symptoms are not caused by the vaccine directly. As well as the deaths that occurred with the sample Which was also identified as not related to the vaccine But all other causes
Opinion of an expert
Specialist in epidemiology and immunology Most have an opinion on the vaccine of The Oxford-AstraZeneca vaccine would have the greatest influence in terms of preventing the spread of COVID-19. For many reasons
The first is the covie shield vaccine. It is not necessary to store in extremely cold temperatures such as -70 ° C in the case of Pfizer / Bio-Entech. But can be stored in the cold of the general refrigerator The cost of vaccination is greatly reduced, and it is also a low price of 3-4 dollars (90-120 baht) per dose, making access to the vaccine more extensive. Especially in developing countries around the world.
In addition, this vaccine can be mass-produced (mass production) more easily than Oxford-AstraZeneca. Confirmed that 3,000 million doses could be produced in 2021, while Pfizer / Bio-Tech production Achieved a maximum of 1,200 million doses and Moderna 1 billion doses in 2021 only.
This is the reason Why is the global focus of the covine shield vaccine among the three vaccines approved at this time?
