What is the status of the novel coronavirus variant that has emerged in India? Does it affect the inoculation effect if the vial contains flocculent? Can two doses of subinactivated vaccine be inoculated with products from different manufacturers? Under the joint prevention and control mechanism of The State Council, a press conference was held in Beijing on May 20. Experts from the China Center for Disease Control and Prevention and the task force for vaccine research and development answered questions from the media on the above-mentioned hot issues.

Our vaccine can deal with the mutated strain

Wu Zunyou, chief expert on epidemiology at the China Center for Disease Control and Prevention, said that the WHO has a global surveillance network for the mutation of the novel coronavirus, to which countries are required to report newly emerging mutated strains in their countries. More than 3,000 mutated strains have been reported in India, as seen on this monitoring network. The actual number of mutated strains is much higher because only a small fraction of the total cases are detected.

"It's not that the more mutant strains, the more scary. It's the nature of the mutation." Wu said the WHO divides virus mutations into three broad categories: the first are particularly "mutant strains that need to be vigilant," such as those seen in the United Kingdom and Brazil; The second category is "mutated strains of concern", such as the one in India; The third category is called "mutated strains of no concern", small mutations that do not need attention.

So, can a domestically produced vaccine cope with India's mutant strain? Shao Yiming, a researcher at the China Center for Disease Control and Prevention, said research was being carried out on the emerging Indian variant. "Right now, there are two things that need to be told to the public." Shao Yiming said that first, Chinese companies and research institutions are closely tracking the mutation of the virus and carrying out targeted research. Preliminary results suggest that the country's vaccine is still capable of dealing with the variant of the novel coronavirus that has emerged in India. Second, if there is a mutant virus strain that the vaccine cannot cope with, we do not need to change the production process of the inactivated vaccine. We only need to change the original vaccine strain to the new mutant strain at the feeding end of production, so that a new vaccine against the mutant strain can be produced. So the public can rest assured that China's vaccine is fully capable of meeting the challenge of the novel coronavirus mutant strain.

Batch by batch inspection can be released to the market

Recently, members of the public reported that a single bottle of vaccine was given to two people during vaccination, and they worried that insufficient dosage would affect the effectiveness of the vaccination. Shao Yiming explained that the two doses of COVID-19 vaccine and the one dose of COVID-19 vaccine in China are the same in terms of raw materials, production formula, packaging materials and technological parameters. The difference lies in whether the dosage is one dose or two doses. "In order to ensure that everyone gets enough, each bottle is sufficient, so there is no need for the public to worry about not getting enough. Internationally, vaccines in many countries, including those exported by China, are given in multiple doses, such as 5 or 10 doses. The benefit is that you can ship more vaccine in the same amount of time, saving packaging, saving shipping capacity for mass vaccination." Shao Yiming said.

Some members of the public expressed concern over the quality of the vaccine after finding flocculent in the vial when they received the vaccine. Shao explained that all COVID-19 vaccines produced by Chinese manufacturers have to go through self-testing in accordance with national standards, and submit to drug testing institutions for batch by batch inspection before they can be released to the market. Each of the finished product of the novel coronavirus vaccine has undergone a strict transparent inspection process, and the products that fail to pass the inspection are directly removed. After passing the inspection, the finished product needs to be sampled for appearance inspection, which should meet the requirements of "milky suspended liquid, which can be stratified by precipitation and easily shaken up". Therefore, the observed novel coronavirus vaccine is often not clear and transparent. Because COVID-19 vaccines contain aluminum adjuvants, resting before use may cause precipitation, but should be able to shake apart.

In addition, some members of the public found that the two doses were produced by different manufacturers after receiving the vaccine, for example, the first dose was produced by Beijing Bio and the second by Beijing Sinovac. They were worried that "mixing" would affect the vaccination effect. In response, Wang Huaqing, chief expert of immunization program of China Center for Disease Control and Prevention, said that currently there are three kinds of conditional Chinese COVID-19 vaccines: inactivated vaccine, adenovirus vector vaccine and protein subunit vaccine. As long as the vaccine is the same technical route, different manufacturers' products will not affect the vaccination effect. "It is clear in the Technical Guidance on COVID-19 vaccination that at this stage it is recommended to complete vaccination with the same vaccine product. In the event that the vaccine cannot be supplied or the recipients are vaccinated in different places, vaccination with the same vaccine product cannot be completed, vaccine products of other manufacturers of the same type can be used to complete vaccination." Wang said that for vaccines that require two or more doses to complete the full course of immunization, follow-up vaccinations generally do not need to be restarted if the specified interval is exceeded. For example, if an inactivated vaccine has not been given a second dose more than eight weeks apart, the second dose can be replaced as soon as possible instead of being revaccinated.