Virus World

BEIJING (AP) — In a rare admission of the weakness of Chinese coronavirus vaccines, the country's top disease control official says their effectiveness is low and the government is considering mixing them to get a boost.  Chinese vaccines “don’t have very high protection rates,” said the director of the China Centers for Disease Control, Gao Fu, at a conference Saturday in the southwestern city of Chengdu. Beijing has distributed hundreds of millions of doses abroad while trying to promote doubt about the effectiveness of the Pfizer-BioNTech vaccine made using the previously experimental messenger RNA, or mRNA, process. “It’s now under formal consideration whether we should use different vaccines from different technical lines for the immunization process,” Gao said.  Officials at a news conference Sunday didn’t respond directly to questions about Gao’s comment or possible changes in official plans. But another CDC official said developers are working on mRNA-based vaccines. Gao did not respond to a phone call requesting further comment. “The mRNA vaccines developed in our country have also entered the clinical trial stage,” said the official, Wang Huaqing. He gave no timeline for possible use.

Experts say mixing vaccines, or sequential immunization, might boost effectiveness. Researchers in Britain are studying a possible combination of Pfizer-BioNTech and the traditional AstraZeneca vaccine. The coronavirus pandemic, which began in central China in late 2019, marks the first time the Chinese drug industry has played a role in responding to a global health emergency. Vaccines made by Sinovac, a private company, and Sinopharm, a state-owned firm, have made up the majority of Chinese vaccines distributed to several dozen countries including Mexico, Turkey, Indonesia, Hungary, Brazil and Turkey. The effectiveness of a Sinovac vaccine at preventing symptomatic infections was found to be as low as 50.4% by researchers in Brazil, near the 50% threshold at which health experts say a vaccine is useful. By comparison, the Pfizer-BioNTech vaccine has been found to be 97% effective. Health experts say Chinese vaccines are unlikely to be sold to the United States, Western Europe and Japan due to the complexity of the approval process.

A Sinovac spokesman, Liu Peicheng, acknowledged varying levels of effectiveness have been found but said that can be due to the age of people in a study, the strain of virus and other factors. Beijing has yet to approve any foreign vaccines for use in China.

Gao gave no details of possible changes in strategy but cited mRNA as a possibility. “Everyone should consider the benefits mRNA vaccines can bring for humanity,” Gao said. “We must follow it carefully and not ignore it just because we already have several types of vaccines already.” Gao previously questioned the safety of mRNA vaccines. He was quoted by the official Xinhua News Agency as saying in December he couldn’t rule out negative side effects because they were being used for the first time on healthy people. Chinese state media and popular health and science blogs also have questioned the safety and effectiveness of the Pfizer-BioNTech vaccine. As of April 2, some 34 million people in China have received both of the two doses required for Chinese vaccines and about 65 million received one, according to Gao. The Sinovac spokesman, Liu, said studies find protection “may be better” if time between vaccinations is longer than the current 14 days but gave no indication that might be made standard practice.

Peru will start testing coronavirus vaccines from China's Sinopharm and U.S. drugmaker Johnson & Johnson in September, researchers said, which should help the country gain faster access to inoculations once the vaccines are approved. Sinopharm began this week to recruit up to 6,000 volunteers in Peru, which Reuters data indicates has the highest number of COVID-19 deaths in relation to its population size. A team of Chinese scientists is expected to arrive in the Andean nation next week to work with local researchers, said Germán Málaga, a doctor and lead vaccine investigator at Lima’s Cayetano Heredia University.  “This is going to happen around Sept. 3, to begin vaccinations on Sept. 8,” he said. Sinopharm’s clinical trials in Peru are being done with Cayetano Heredia and the state-run Universidad Mayor de San Marcos.

Peru has recorded around 622,000 cases of the coronavirus, the fifth highest case load in the world, and 28,277 deaths. It now has the world’s deadliest fatality rate per capita, with 86.67 deaths per 100,000 people, a Reuters tally shows, just ahead of Belgium.  Sinopharm will also do clinical coronavirus vaccine trials elsewhere in Latin America, including in Argentina. Other Chinese laboratories that will be conducting trials in the region include Sinovac Biotech, which will work in Brazil and Chile, and Walvax Biotechnology Co Ltd and CanSino Biologics Inc, which will test in Mexico, authorities have said. Johnson & Johnson’s Janssen unit will start tests with some 4,000 volunteers in Peru around Sept. 24, Prime Minister Walter Martos told reporters on Thursday.  “We are contacting other companies, laboratories, from Britain and other countries that are going to help us immunize at least 70% of the local population,” Martos said. J&J said earlier this week that it would conduct Phase III trials for its vaccine in Chile, Argentina and Peru.