“Relying on only vaccines cannot contain [Chinese coronavirus],” Wu Zunyou, the Chinese Center for Disease Control and Prevention’s chief epidemiologist, told China’s state-run Global Times on Sunday.

Wu referred to “COVID-19,” or the name of the disease caused by SARS-C0V-2, a type of coronavirus. The disease is also known as the Chinese coronavirus.

“China has already reached a 70 percent vaccination rate, but as long as the virus [SARS-CoV-2] can evade herd immunity, people can still get infected, like the recent outbreak in Tianjin, where many infected people were vaccinated, although the symptoms were milder,” Wu told the Global Times on February 6.

Tianjin is an eastern Chinese port city directly bordering Beijing with an estimated population of 15.6 million. Chinese Communist Party officials in Tianjin eased house arrest measures for some inhabitants of the city on January 22 after locking down the municipality on January 9 to contain a local coronavirus outbreak.

“In the last few weeks, Tianjin tested every resident for COVID-19 four times, uncovering dozens of new infections,” Fortune reported on January 24. “Tianjin announced zero cases once again last week, and on Saturday [January 22], the city lifted lockdown measures for thousands of residents who remained in isolation.”

Toyota, a Japanese car manufacturer, announced on January 22 it had resumed operations at a factory it operates in Tianjin after local Communist Party authorities forced the plant to close on January 10 as part of the city’s lockdown.

Chinese coronavirus vaccines failed to prevent transmission of the virus within Tianjin in January despite the city’s high vaccination rate, as Wu acknowledged on February 6. The top Chinese epidemiologist said SARS-CoV-2’s high mutation rate has contributed to its ability to evade vaccine-imparted immunity.

“Since its emergence, the SARS-CoV-2 virus has continued to evolve and WHO has designated five variants as SARS-CoV-2 Variants of Concern (VOC) to date – namely Alpha, Beta, Gamma, Delta and Omicron – due to their impact on transmission, disease severity, or capacity for immune escape,” the World Health Organization (W.H.O.) wrote January 11.

“While the Omicron variant is spreading rapidly across the world, the evolution of SARS-CoV-2 is expected to continue and Omicron is unlikely to be the last VOC,” according to the United Nations public health body.

Most global health authorities currently believe SARS-CoV-2 first emerged in Wuhan, China, in the fall or winter of 2019, though much about the virus’s true origin remains unknown.

China has largely used its own domestically developed and manufactured Chinese coronavirus vaccines and vaccine candidates to inoculate its population against the disease.

“[C]urrent vaccines don’t have very high protection rates,” the director of the Chinese Center for Disease Control and Prevention, Gao Fu, told a health conference in southwestern China’s Chengdu city in April 2021.

Gao told the Associated Press (AP) on April 11, 2021, he referred to the efficacy of “vaccines in the world, not particularly for China” when speaking at the Chengdu conference.

“China currently has five vaccines in use in its mass immunization campaign, three inactivated-virus vaccines from Sinovac and Sinopharm, a one-shot vaccine from CanSino, and the last from Gao’s team in partnership with Anhui Zhifei Longcom,” the AP observed at the time of domestic Chinese coronavirus vaccines.

“The effectiveness of the vaccines range from just over 50% to 79%, based on what the companies have said,” the news agency noted.

“The shot from Gao’s team, was given emergency use approval a month ago, and has not publicly disclosed data yet about its efficacy,” according to the AP.