Marie Neige, a call center operator in the Seychelles, really wanted to be vaccinated. Like the majority of residents of the tiny island nation, she received China’s Sinopharm vaccine in March and should be fully protected in a few weeks.

She tested positive for the coronavirus on Sunday.

“I was shocked,” said Ms. Neige, 30, who is isolated at home. She said she had lost her sense of smell and taste and had a slight sore throat. “The vaccine should protect us – not from the virus, but from the symptoms,” she said. “I took precautionary measures after precautionary measures.”

China expected its Sinopharm vaccines to be the linchpin of the country’s vaccine diplomacy program – an easy-to-carry dose that would protect not only Chinese citizens but much of the developing world as well. China has donated 13.3 million doses of Sinopharm to other countries to gain goodwill, according to Bridge Beijing, a consulting firm tracking China’s impact on global health.

Instead, the company that made two types of coronavirus vaccines faces growing questions about the vaccinations. First, there was a lack of transparency in the late-stage experimental data. Now, Seychelles, the world’s most vaccinated nation, has seen increases in some cases, despite the fact that much of its population has been vaccinated with Sinopharm.

For the 56 countries that are counting on Sinopharm’s shot to stop the pandemic, the news is a setback.

For months, public health experts had focused on bridging the access gap between rich and poor nations. Now scientists are warning that developing countries that choose to use the Chinese vaccines, with their relatively weaker efficacy rates, could lag behind those choosing vaccines from Pfizer-BioNTech and Moderna. This loophole could allow the pandemic to continue in countries with fewer resources to fight the pandemic.

“You have to be using really powerful vaccines to get this economic benefit or you will be living with the disease long term,” said Raina MacIntyre, who heads the biosecurity program at the Kirby Institute, University of New South Wales in Sydney, Australia. “The choice of vaccine is important.”

Nowhere have the consequences been more apparent than in the Seychelles, which relied heavily on a Sinopharm vaccine to vaccinate more than 60 percent of their population. The tiny island nation in the Indian Ocean, northeast of Madagascar and with a little over 100,000 inhabitants, is fighting a wave of the virus and had to impose another lockdown.

Of the vaccinated population who received two doses, 57 percent received Sinopharm while 43 percent received AstraZeneca. Thirty-seven percent of the new active cases, according to the Ministry of Health, are fully vaccinated people who did not indicate how many people among them received the Sinopharm shot.

“At first glance, this is an alarming finding,” said Dr. Kim Mulholland, a pediatrician at Murdoch Children’s Research Institute in Melbourne, Australia who has been involved in overseeing many vaccine studies, including those for a Covid-19 vaccine.

Dr. Mulholland said the first reports from the Seychelles correlate with a 50 percent rate of effectiveness for the vaccine instead of the 78.1 percent rate the company has touted.

“We would expect in a country where the vast majority of the adult population has been vaccinated with an effective vaccine to see the disease melt away,” he said.

Scientists say breakthrough infections are normal because no vaccine is 100 percent effective. The Seychelles experience, however, is in stark contrast to Israel, which has the second highest vaccination rate in the world and has managed to fight back the virus. A study showed that the Pfizer vaccine used by Israel was 94 percent effective at preventing transmission. On Wednesday, the number of new confirmed Covid-19 cases per million people in the Seychelles stood at 2,613.38 compared to 5.55 in Israel, according to The World In Data project.


May 12, 2021, 12:34 p.m. ET

Wavel Ramkalawan, the President of Seychelles, defended the country’s vaccination program, saying that the vaccines against Sinopharm and AstraZeneca “have served our people very well”. He pointed out that the Sinopharm vaccine was given to people aged 18 to 60, and that in that age group, a total of 80 percent of patients who had to be hospitalized were not vaccinated.

“People may be infected, but they are not sick. Only a small number, ”he told the Seychelles News Agency. “So what happens is normal.”

Minister for Foreign Affairs and Tourism Sylvestre Radegonde said the surge in cases in Seychelles was partly due to people abandoning their vigilance, according to the Seychelles News Agency. Sinopharm did not respond to a request for comment.

In response to a Wall Street Journal article on Seychelles, a Chinese Foreign Ministry spokeswoman accused the Western media of attempting to discredit Chinese vaccines and “cultivating the mentality that” everything related to China must be smeared “.

In a press conference, Kate O’Brien, director of vaccinations at the World Health Organization, said the agency assessed the rise in infections in the Seychelles and called the situation “complicated”. Last week the global health group approved the Sinopharm vaccine for emergency use, raising hopes of an end to the global supply crisis.

She said that “some of the cases that are reported occur either shortly after a single dose, or shortly after a second dose, or between the first and second dose.”

According to Ms. O’Brien, WHO is studying the strains currently circulating in the country, when the cases occurred, relative to when someone was dosed and the severity of each case. “Only through this type of assessment can we judge whether or not it is vaccination failure,” she said.

However, some scientists say it is becoming increasingly clear that the Sinopharm vaccine does not offer a clear path to herd immunity, especially considering the numerous variants that appear around the world.

Governments using the Sinopharm vaccine must “accept a significant failure rate and plan accordingly,” said John Moore, a vaccine expert at Cornell University. “You need to make the public aware that you still have a good chance of getting infected.”

Many in Seychelles say the government was not ready.

“My question is, why did you push everyone to take it?” said Diana Lucas, a 27-year-old waitress who tested positive on May 10th. She said she received her second dose of the Sinopharm vaccine on February 10th.

Government attorney Emmanuelle Hoareau, 22, tested positive on May 6th after the second dose of the Sinopharm vaccine in March. “It doesn’t make sense,” she said. She said the government failed to provide enough information about the vaccines to the public.

“They don’t explain the real situation to people,” she said. “It’s a big deal – a lot of people get infected.”

Ms. Hoareau’s mother, Jacqueline Pillay, is a nurse at a private clinic in Victoria, the capital. She believes there is a new variant in the Seychelles because a lot of foreigners have arrived in the last few months. The tourism-dependent country opened its borders to most travelers without quarantine on March 25.

“People are very scared now,” said Ms. Pillay, 58. “If you gave people the right information, people wouldn’t speculate.”

Health officials recently appeared on television to encourage those who only took the first dose of the Sinopharm vaccine to come back for the second shot. But Ms. Pillay said she was frustrated that the public health officer hadn’t addressed why the vaccines don’t seem to be working as well as they should.

“I think a lot of people don’t come back,” said Ms. Pillay.

Marietta Labrosse, Elsie Chen, and Claire Fu have contributed to the research.