The need for clarity about the safety and effectiveness of China's vaccines has become more urgent after Sinopharm announced that it had vaccinated around one million people prior to the completion of clinical trials. The campaign has alarmed scientists from overseas who claim it is exposing people to inappropriate risks.
Chinese officials have repeatedly assured the public that the country's coronavirus vaccines are safe, giving few details. Last month, Liu Jingzhen, the chairman of Sinopharm said none of those who received the company's vaccines had experienced any side effects. He said that "few had mild symptoms."
The road to a coronavirus vaccine
Interesting facts about vaccines
Confused by all of the technical terms used to describe how vaccines work and study? Let us help:
- Adverse event: A health problem that occurs in volunteers in a clinical trial with a vaccine or drug. An adverse event is not always caused by the treatment tested in the study.
- Antibody: A protein produced by the immune system that can attach itself to a pathogen such as the coronavirus and prevent it from infecting cells.
- Approval, licensing and approval for emergency use: Medicines, vaccines and medical devices cannot be sold in the US for no profit approval by the Food and Drug Administration, also known as Licensing. After a company has submitted the results of clinical studies to the F.D.A. For testing purposes, the agency decides whether the product is safe and effective. This process usually takes many months. If the country faces an emergency – like a pandemic – a company can file an application instead Emergency approvalthat can be granted much faster.
- Background rate: How often does the general population experience a health problem called an Adverse Event? To determine whether a vaccine or drug is safe, the researchers compare the rate of adverse events in one study to the background rate.
- Effectiveness: The benefit of a vaccine compared to a placebo, measured in a clinical trial. For example, to test a coronavirus vaccine, the researchers compare how many people in the vaccinated group and the placebo group are receiving Covid-19. In contrast, effectiveness is the benefit that a vaccine or drug offers in the real world. A vaccine's effectiveness can be found to be less or more effective than its effectiveness.
- Phases 1, 2 and 3 studies: Clinical trials typically take place in three phases. Phase 1 studies typically involve a few dozen people to determine whether a vaccine or drug is safe. In Phase 2 studies, involving hundreds of people, researchers can try different doses and take more measurements of the vaccine's effects on the immune system. Phase 3 trials, involving thousands or tens of thousands of volunteers, determine the safety and effectiveness of the vaccine or drug by waiting to see how many people are protected from the disease it is supposed to be fighting.
- Placebo: A substance with no therapeutic effect that is widely used in clinical trials. For example, to see if a vaccine can prevent Covid-19, researchers can inject the vaccine into half of their volunteers while the other half are given a placebo with salt water. You can then compare how many people are infected in each group.
- Post-market surveillance: The surveillance that occurs after a vaccine or drug has been approved and regularly prescribed by doctors. This monitoring usually confirms that the treatment is safe. In rare cases, side effects are noted in certain groups of people that were overlooked during clinical trials.
- Preclinical Research: Studies that take place prior to the start of a clinical trial typically include experiments that test a treatment on cells or animals.
- Viral vector vaccines: A type of vaccine that uses a harmless virus to deliver immune-stimulating ingredients into the human body. Viral vectors are used in several experimental Covid-19 vaccines, including those developed by AstraZeneca and Johnson & Johnson. Both companies use a cold virus called adenovirus as a vector. The adenovirus carries coronavirus genes.
- Test protocol: A series of procedures that must be performed during a clinical trial.
In October, Zheng Zhongwei, a senior health official, said the government had set up a "follow-up program" to track down those vaccinated, although he did not provide details.
Sinovac Biotech, a Beijing-based private vaccine maker, has already started exporting its vaccines to countries like Indonesia and Brazil. Sinopharm, which has another late-stage vaccine, is preparing to ship 500 million doses worldwide, according to the state-run Science and Technology Daily.
It is unclear whether the Emirates will use the Chinese vaccine, which Sinopharm developed together with the Beijing Institute of Biological Products, for mass vaccination. The government approved the vaccine for emergency use back in September for frontline workers who are at risk of contracting Covid-19.
Some other countries where Sinopharm is conducting studies rely on Chinese vaccines to protect their populations. Morocco says it is preparing to vaccinate 80 percent of its adults, relying on a Sinopharm vaccine initially, though it would wait for China to approve the vaccine, according to Médias24, a Moroccan news website.
The Chinese vaccines also appeal to developing countries as they may be easier to distribute. According to Sinopharm, the vaccines need to be cooled at temperatures of just 2 to 8 degrees Celsius and can remain stable for up to three years. In contrast, Pfizer and Moderna vaccines, which are made from genetic materials that fall apart when thawed, require industrial freezers, which makes transport and storage more difficult.