[NTD News September 13, 2021, Beijing time]The intravenous COVID-19 human immunoglobulin (pH4) developed by China National Pharmaceutical Group has been approved for clinical trials. The mainland media called this drug “the first new crown-specific drug”. Is that really the case? What is the prospect of the drug in clinical use?
Is the intravenous COVID-19 human immunoglobulin (pH4) developed in China the first specific drug?
The official website of Sinopharm said on September 3 that the company’s newly developed intravenous COVID-19 human immunoglobulin (pH4) is the world’s first immunized plasma with a new coronary inactivated vaccine as a raw material, which is specific for new coronary pneumonia. drug.
China has a huge population of people who use Sinopharm and Kexing vaccines. The production process of this drug is to collect the plasma of these people to separate the immunoglobulins (antibodies) obtained after vaccination. During treatment, these immunoglobulins Inject into the patient’s body.
Dr. Lin Xiaoxu, former director of the Department of Virology at the US Army Research Institute, explained that in the past, administering immunoglobulin to people with insufficient immunity was a common medical technique to “provide some extra shells” to deal with enemies invading the body.
There are effective treatments for the new coronavirus, such as monoclonal antibody therapy. Lin Xiaoxu believes that this new coronary pneumonia specific treatment drug is exaggerated by the media as the “world’s first” and “new crown specific drug”.
“Some people think that another new treatment plan has come out, but it is actually not that simple.” Lin Xiaoxu said, this drug has just started clinical trials, and it may face some challenges in practical applications in the future.
What are the problems facing the manufacture of immunoglobulin drugs from the blood of the vaccinee?
He further stated that the manufacturing process and use of the drug itself face 7 problems and challenges:
1. The quality and safety of plasma at blood collection points in various places are prone to unevenness.
Lin Xiaoxu explained that to collect immunoglobulins, at least more than 1,000 people’s plasma is needed to have a sufficient amount. These people who have been vaccinated may be distributed in different cities. Whether each blood collection point can guarantee the safety and quality of these blood samples is a question in itself.
In addition, the inactivated vaccines of Sinopharm and Kexing do not have as high levels of antibodies in the vaccinators as the mRNA vaccines. Therefore, it is natural to collect more blood plasma.
2. How long does it take to donate blood after vaccination, and whether the blood donor takes other drugs.
The control of blood donors is also very important, including whether they are taking other medicines, how long they receive blood draws after vaccination, and so on.
The concentration of antibodies obtained by vaccination will decrease over time, which is likely to cause great fluctuations in the amount of new crown antibodies contained in the collected plasma. Although blood donors can be screened, for example, the plasma of people who have been injected for about one month is limited. However, some places may be more difficult to control.
3. The production technology, quality control (including various residues) of the separation process, and the stability of immunoglobulins.
The production process of separating immunoglobulins from plasma includes many steps: how to remove residues, such as stabilizers used for separation, clotting factors in plasma, etc.; how to maintain the stability and effectiveness of the separated immunoglobulins price. These are the tests that the drug manufacturing process will face.
4. How to keep the quality of different batches of medicines relatively stable.
Whether it is a clinical trial or a therapeutic drug to be launched in the future, there will be different batches of isolated immunoglobulins. It is more difficult to ensure consistent quality.
Lin Xiaoxu explained that because blood is collected from different groups of people, there will definitely be quality differences in different batches. Including the stability and titer of immunoglobulins, and how many of these immunoglobulins are antibodies against the new coronavirus.
5. Among the isolated immunoglobulins, what proportion is the neutralizing antibody of the new coronavirus?
Among the immunoglobulins isolated from plasma, what proportion of the neutralizing antibodies against the new coronavirus account for, and how to evaluate the titer of these antibodies, are the core issues that these drugs can be effective.
6. Monitoring standards for the titer of neutralizing antibodies against the new coronavirus.
Neutralizing antibody titers will vary greatly with different evaluation methods. “This evaluation itself also has a certain degree of difficulty,” Lin Xiaoxu said.
7. How can it neutralize the mutant virus?
The current Sinopharm and Kexing inactivated vaccines, like other vaccines, are based on the original new coronavirus. Today, the Delta variant virus is raging around the world, replacing the original virus. The Delta variant itself has a higher immune escape ability. Therefore, it is difficult to determine the protective effect of the immunoglobulin extracted from the vaccinated person on the Delta variant.
At present, it seems that the new crown virus has undergone a key mutation in a few months, from the Alpha, Beta, Gamma mutation to the now raging Delta, Mu and other variants, only about half a year. Whether drug development can keep up with the speed of virus variants is also difficult to say.
Lin Xiaoxu added that immunoglobulin therapy is mainly aimed at people with immunodeficiency. It is difficult for these people to get enough antibodies by vaccinating to get protection through intravenous injection of immunoglobulin. He reminded that if this treatment plan passes clinical trials in the future, not all people will be used in treatment.
In a chaotic world, if you have a healthy way, look at health 1+1!
(Reposted from The Epoch Times/Editor in Charge: Li Lezhen)
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