A senior citizen receives COVID-19 vaccine at a vaccination site in Haizhu district of Guangzhou, south China's Guangdong Province, April 7, 2022. Photo:Xinhua

A well-timed second booster dose is necessary for a safe, long-term exit from the pandemic, the Chinese Center for Disease Control and Prevention (China CDC) said in a recent article, confirming the necessity of a fourth shot against COVID-19. It also called on the last 10 percent of the country's population who have yet to be fully vaccinated to take shots as soon as possible.

The article titled "Perspectives: Vaccinate with Confidence and Finish Strong" was recently published by the China CDC Weekly. Some of the leading experts and officials of the China CDC, such as Yin Zundong, Lance Rodewald and Feng Zijian, are among the authors.

To achieve sustained, optimized protection for a safe, long-term exit from the pandemic, the China CDC article clearly said that well-timed second booster doses are certainly required. It said that the design of its second booster dose strategy will be based on emerging evidence of the duration of protection afforded by the vaccines.

The Global Times learned from a source close to the matter that the country has started clinical research on the second booster shot. 

Whether to roll out a fourth dose has been widely discussed in China. Previously, Chinese experts have said that it's important to know how long immunity from the second booster can last, and how it will benefit the general population, before the fourth dose - the second booster shot - can be rolled out.

At the end of 2021, Israel announced the start of the fourth dose of COVID-19 vaccine, and the US, Germany and Thailand also start the fourth dose. 

Data from the State Council released on August 9 showed that more than 1.2 billion people had been fully vaccinated, accounting for 89.96 percent of the total population. People who had received a booster shot exceeded 821 million, the data showed. 

It said China's strategy of containing the epidemic has spared over 99 percent of the 1.4 billion Chinese people from exposure to and infection with severe cases of COVID-19 and its variants for an astonishing two and a half years. Though it came with social and economic costs, the strategy earned the country a great deal of time for tools, such as vaccines, to escape the pandemic while keeping infection and death from the infectious disease at a low level. 

But now there is precious little time left to finish the vaccination campaign, which aims to achieve broad and deep vaccine-induced population immunity strong enough to prevent suffering and death from COVID-19. The article stressed that effective population immunity must be built one person at a time until all are protected, which is undoubtedly a daunting task for such a populous country. 

"Everyone wants to return to normal life. Vaccination is the key," said the article.

The last 10 percent that has yet to be fully vaccinated is the most difficult to reach but also a critically important group to protect. It includes many people with comorbidities, many of whom are elderly and will suffer the most from COVID-19 if infected, the China CDC article noted.

In the article, Chinese officials and experts highlighted safety and effectiveness of China-produced COVID-19 vaccines. It said that "China-produced vaccines have the greatest effectiveness where it is needed the most — prevention of serious, critical and fatal COVID-19 among people of all ages and regardless of comorbidities."

The article quoted a population-based study of inactivated vaccine safety among people 60 years or older in the Hong Kong Special Administrative Region, saying China found no increased risk of adverse events, regardless of whether the patient was older or younger than 80, and regardless of the presence of comorbidities.

It also stated that pregnant women can join the vaccination campaign since there is no evidence to support a pregnancy contraindication, and over two-thirds of countries recommend vaccinating pregnant women, including with China-produced inactivated vaccines. 

"Regulatory authorities and manufacturers should work to remove the contraindication to vaccination during pregnancy" so they can join the vaccination campaign and be protected from COVID-19.