BUDAPEST, Hungary – New study suggests Sinopharm vaccine offers poor protection against COVID-19 in the elderly, raising questions for dozens of countries that have administered Chinese society’s vaccines to their most populous populations. vulnerable.
A survey of blood samples taken from 450 people in Hungary at least two weeks after their second dose of Sinopharm found that 90% of those under 50 developed protective antibodies. But the percentage decreased with age, and 50% of those over 80 did not.
The study by two Hungarian researchers went online this week but has yet to be reviewed by other scientists. Three outside experts said they had no problem with the vaccine study methodology developed by Sinopharm’s Biologics Institute in Beijing.
“It is very, very worrying that these people, who are at high risk, have a poor antibody response,” said Jin Dong-yan, a virologist at the University of Hong Kong who was not affiliated with the study.
Antibody levels are not a direct measure of how well a person is protected against COVID-19, but there is growing evidence that they are a good indicator. An expert warned that the choice of test kits may have limited the accuracy of the measurements.
Still, the study results are valuable and are the first public scientific attempt to analyze the effect of the Sinopharm vaccine in the elderly, said Wang Chenguang, former professor at Peking Union Medical College and expert in immunology.
China’s National Health Commission declined to comment on the study, saying it would only respond to studies from governments or major research institutions.
A WHO spokesperson said Wednesday that its experts “are aware of the study and continue to review all available evidence.” The agency’s advisers raised questions months ago about whether it offered protection to people 60 and older, but when that was okay, a WHO expert said there was no reason to think it would work any differently in the elderly.
The vaccine is one of two similar vaccines developed by Sinopharm. Research from the Chinese state-owned company has shown that almost all of the participants in the end-stage clinical trials were under the age of 60 – and its own researchers said there was not enough evidence to say whether vaccines work in old people. Overall, the Beijing Institute vaccine was found to be 78% effective.
In Hungary, concern over the injections has led many to seek private antibody tests. Eventually, the capital Budapest offered free tests to elderly residents as part of an attempt to step up pressure on the government to conduct its own broader investigation and provide booster shots to those in need.
After initially pushing back calls for a government response to efficiency concerns – including from antibody study authors Balazs Sarkadi and Tamas Ferenci – Prime Minister Viktor Orban finally nodded last week to the growing public anger. He announced that the government would offer its citizens an optional third shot.
His office said, however, that all vaccines authorized by Hungary are effective.
The United Arab Emirates and Bahrain both announced in May that they would also offer a third dose of Sinopharm over concerns over an insufficient antibody response. Bahrain has recommended that people over 50 and some other vulnerable people receive Pfizer-BioNTech’s vaccine as a booster, whether or not they initially received Sinopharm.
CNBG, the Sinopharm subsidiary that oversees the Beijing Institute, said a third dose was not part of the company’s clinical guidelines.
It is not known how many doses of the Beijing Institute’s Sinopharm vaccine were exported. Overall, China exported 500 million doses of the vaccine in the first half of the year, and the company is one of the country’s two largest COVID vaccine manufacturers, along with privately-held Sinovac.
The Global Alliance for Vaccines and Immunization recently ordered 550 million doses from the two companies for the UN-backed COVAX program.
Both Sinopharm vaccines are also widely used in China, including in the elderly. The country’s National Health Commission said in April that the injections offered some protection, although it recognized that early stages of clinical trials of Sinopharm and two other vaccines found fewer antibodies in people over 60. years and older.
In Budapest, Beata Englohner worried about her 76-year-old mother after learning that people vaccinated with Sinopharm did not have antibodies.
Englohner created a Facebook group to pressure the government to tackle the problem. She is cautiously optimistic now that Hungary will offer a third dose.
“We are very happy to have achieved our goal and to have been heard,” she said. “Although we are a little afraid to receive what we have already obtained before.”
Wu reported from Taipei, Taiwan.