A glimpse into Sinovac's COVID-19 vaccine work

About 500 million doses of the CoronaVac vaccine developed by Beijing-based Sinovac Life Sciences can be produced each year in the capital's southern suburbs.

"The production line for the second phase of our vaccine solutions will be put into operation in February, with a projected annual production capacity of more than 1 billion doses," said Yin Weidong, CEO of Sinovac Biotech, which has a majority stake in the vaccine producer.

On Dec 15, China officially launched its COVID-19 vaccination program for the winter-spring period, targeting a number of key groups, including those engaged in handling imported cold-chain products, customs officers, medical workers and people working in the public transport sector and fresh food markets.

Over 10 million doses have already been administered in China, according to the country's health authorities.

Since the company's vaccine workshops began operating in August, workers and machines have been working around the clock to ensure domestic vaccine supply and help uphold China's commitment to making its self-developed vaccines a global public good, Yin said.

From cell culture to packaging, a dose of vaccine can be produced in just 48 days. The company is now churning out about 400,000 doses a day for domestic needs.

In the company's workshops, automated equipment can be seen everywhere, and it's all for the safety of workers as it helps minimize direct human contact with the vaccine ingredients.

Inactivated COVID-19 virus is first purified and tested before it goes through proportioning into a semifinished product. In the filling workshop, staff equipped with special rubber gloves inspect the syringes and check for foreign matter in the pharmaceutical containers off the production line. Stringent sampling inspection is also conducted in the laboratories to ensure the syringes are fit for use.

"Our vaccine has very good stability as it met the national quality criteria after being kept at 25 C for 42 days or 37 C for 21 days," Yin said, adding that the doses could be stored at 2 C to 8 C for a very long time. In fact, the current expiration date is three years.

Sinovac Life Sciences uses cold-chain vehicles to transport the vaccines to far-flung centers for disease control and prevention in China. The vaccines are packed in temperature-controlled boxes to be transported by air to other parts of the globe. Thermometric indicators monitor and record conditions during the entire process to ensure the safety and effectiveness of the vaccines.

"Recipients can use designated software to read the recorded data to verify that the vaccine has indeed been kept between 2 C and 8 C," Yin said.

The vaccine producer recently shipped semifinished syringes, equivalent to 15 million doses, to Indonesia. China's vaccine enterprises have been urged to plan and increase production capacity and contribute to vaccine accessibility and affordability in developing countries.

"Currently, our vaccines have been exported to countries including Brazil, Turkey and Indonesia," Yin said. "A part is exported as semifinished jabs and will be completed with the help of filling and packing lines set up overseas to boost global supply capacity."

China has announced that after its self-developed vaccines are approved and made available to the public, they will be offered free to Chinese people, who can receive inoculations on a voluntary, informed basis.

The cost of COVID-19 vaccinations, including the purchase of the vaccine and inoculation fees, will be covered by medical insurance and government funds.