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  • Dr Jonathan Gui

SINOVAC - CHINA COVID-19 VACCINE

Sinovac is now competing with other world COVID-19 vaccine players like Pfizer, Moderna, and Johnson & Johnson. The COVID-19 outbreak was firstly reported in Wuhan, China and they were the first country to embark on vaccine production by using the inactivated COVID-19 virus.


There are many other vaccines which, use inactivated (killed) bacterias or viruses such as:

  1. Virus

  2. Polio vaccine

  3. HFMD vaccine

  4. Tick-borne encephalitis vaccine.

  5. Hepatitis A vaccine

  6. Rabies vaccine

  7. Bacteria

  8. Injected typhoid vaccine

  9. Cholera vaccine

  10. Plague vaccine

  11. Pertussis vaccine

How does Sinovac Vaccine work?

Now Sinovac COVID-19 vaccine joins the list of killed vaccines. The real COVID-19 virus is grown in Vero Cells (medium or nutrient for the virus to replicate and produce more copies of itself). The grown virus is then killed and stabilized to be use changed into a vaccine.


The concept is to use the killed virus to generate an immune response against the COVID-19 virus. A person who never got the vaccine will take at least 10 days to generate some antibodies against the COVID-19 virus by that time the body may already be overrun by the COVID-19 virus infection causing more complications. Vaccination against COVID-19 will give a faster response time because the antibodies are already present in the body before infection as compared to a person who never got the vaccine.


Is there a study published by the Sinovac COVID-19 vaccine?

Currently, Sinovac is still running its phase III trials all over the world including UAE, Bahrain, Egypt, Jordan, Peru, Argentina, Morocco, Indonesia, and Malaysia. In Malaysia, there were 3000 participants recruited. We do not have much data about the efficacy and the safety profile as Sinovac is still in the Phase III trial and their trial results have not been published.


All phase 1 to phase 3 is to determine efficacy and safety but the number of people enrolled in the study is different. The more people enrolled in the study will give the investigator of the vaccine more details and accurate data. We start off with Phase I with about 20-80 participants, phase II recruits hundreds of participants and then Phase III requires thousands of participants.



This means that since Sinovac is still in its Phase III trial, the vaccines we are getting from China are for emergency use only as in Phase I and Phase II trials have shown that it is safe and effective. Other vaccines like Pfizer, Moderna, and Johnson & Johnson also have data published until Phase III and have been approved by the US to be given to Americans under the emergency act.


Even if the vaccine is approved under the emergency act, this does not mean that the vaccine is not suitable for the general population but rather the vaccine is to help increase survival and reduce the infective rates against COVID-19 so that be can return to normalcy.


COVID-19 has raved the entire global economic sector. The vaccine needs more long-term studies to establish its side effects, safety, and efficacy. However, in this pandemic, we have no choice but to get the vaccines into our arms rather than to sit and wait.

It will be for many years more before this vaccine can be guaranteed to be safe.


The Control of Disease Center (CDC) has agreed that the benefits outweigh the risk. I believe that the Phase I to phase III trials have already shown good safety and efficacy profile of the vaccine in a smaller population group, therefore in my professional opinion; the vaccine should be relatively safe and effective to most of the general population receiving the vaccine.


There is nothing for certain about the vaccines against COVID-19 in this already uncertain state that the world is in. Faith is all we have now!

What is the progress of the China COVID-19 vaccine?

The progress of the China vaccines have been reported via news and on the Sinopharm website but the clinical study remains unpublished.

  1. 16/03/20: (unofficial trial): Wuhan Institute of Biological Products and the Wuhan Institute of Virology under the Chinese Academy of Sciences is the earliest institute to start on phase 1 trial on the inactivated viruses.

  2. 10/04/20: China government officially gave approval for trials

  3. 12/04/20:

  4. Sinopharm planned a double-blind placebo-controlled human trial of their inactivated virus

  5. Academy of Military Medical Science of People's Liberation Army & Chinese firm (CanSino Bio) did a trial on the recombinant protein of adenovirus.

  6. 12/04/20: 5 noteworthy companies researching and developing 5 types of vaccines:

  7. Gene recombinant protein vaccine - Academy of Military Medical Science of People's Liberation Army & Chinese firm (CanSino Bio)

  8. Adenovirus vector - information not available

  9. Nucleic Acid vaccine - information not available

  10. Attenuated Influenza vector - information not available

  11. Inactivated virus vaccine produced by:

  12. Wuhan Institute of Biological Products and the Wuhan Institute of Virology under the Chinese Academy of Sciences is the first institute to develop the vaccine.

  13. Beijing Institute of Biological Products and the Chinese Center for Disease Control and Prevention is the second institute to develop the vaccine.

  14. Sinopharm is the third institute to develop the vaccine.

  15. 14/04/20: Sinovac (Sinopharm) starts the trial

  16. 24/04/20: (officially phase 2 trial): Wuhan Institute of Biological Products and the Wuhan Institute of Virology under the Chinese Academy of Sciences did their phase II trials on the inactivated viruses.

  17. 30/05/2020: Sinopharm started mass production of their inactivated vaccines as the phase II trial is coming to an end. The vaccines will be used for phase III in the international arena.

  18. 17/06/2020-20/06/2020: Sinopharm vaccine is proven safe and effective in clinical trials and discussions on the way for international phase III trials.

  19. 23/06/2020: Phase III to be launched in UAE and Bahrain with about 40000-50000 participants.

  20. 11/11/2020: Other countries join the phase III trial like Egypt, Jordan, Peru, Argentina, and Morocco.

  21. 09/12/2020: Concluding the phase III trial has shown efficacy ranging from 50.4% in Brazil, 86% efficacy in UAE, and China 79.3%. However other rates like 99 % seroconversion rate of neutralizing antibody and 100% effectiveness in preventing moderate and severe cases of COVID-19 are similar among the different countries.

  22. We predict by the end of April 2021 phase III trials will be completed and roll out of the Sinopharm vaccine.


When will the Sinovac vaccine be approved for use?

World Health Organization (WHO) will review on April 26 Chinese drugmaker Sinopharm's COVID-19 vaccine for possible emergency use listing, to be followed by the Sinovac jab on May 3,



What are the side effects of the Sinovac vaccine?

The Sinovac vaccine is undergoing phase III trials and the details are not readily available. Nevertheless reported side effects may range from:

  • Local

  • Localised swelling of the injection area

  • Systemic

  • Headache

  • Dizziness

  • Rashes

  • Muscle aches



What is the efficacy of the Sinovac vaccine?

The Sinovac vaccine has mixed results in terms of its efficacy from one country to another. It is a wonder what is the reason that their SInovac vaccine has so many discrepancies.


Generally, the COVID-19 virus started to mutate and newer variants are appearing. It is possible that the Sinovac vaccine was developed against the initial variant of the virus and may not be as effective against the newer variants.

The effectiveness of the vaccine also depends on the age category, exposure risk, co-morbidity and immune response of the individual, therefore the efficacy of the vaccine will vary.

Read more about the efficacy reported in the image below:



Is the Sinovac vaccine safe for HIV patients?

Currently, most of the vaccines produced are deemed safe by the United Nations for people living with HIV. The China Sinovac vaccine uses inactivated viruses. Like many other inactivated vaccines they are generally safe and can be used in people living with HIV as the vaccine is not a live vaccine. The live vaccine is not recommended for people living with HIV because the live vaccine may cause disease if the host immune response is poor, however, the Sinovac vaccine is a dead virus being injected into the host to stimulate an immune response.


Most vaccines have a similar safety profile. For people living with HIV, there are still common guidelines before using most vaccines. Anyone living with HIV is advised to ensure that you have good CD4 counts of at least 200, stable Viral load which is undetectable and must be on treatment.


Overall the ongoing phase III study shows that side effects are minimal with a more localised reaction like injection site swelling and muscle ache.


I will update more about the Sinovac trials after World Health Organisation (WHO) has reviewed the phase III trials results from Sinovac.


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