China is facing the worst resurgence of the coronavirus since it quashed nearly all of its cases months ago, adding pressure to the rollout of vaccines to its vast population.
Amid this pressure is recent news from Brazil that a Chinese-developed vaccine showed significantly lower efficacy rate in very mild cases compared to its global peers.
China reported 107 locally transmitted cases of coronavirus on Wednesday, according to its National Health Commission, the most since July. The day before, it reported 85 cases. The numbers may seem small compared to the thousands of daily cases in places like the U.S., but after a hard lockdown a year ago, China has seen few large outbreaks and many days with no cases.
The commission said 90% of the new cases are in Hebei province, which encircles Beijing. The capital has been notoriously quick to lock down even amid a scattering of cases, and the new scare has led to 28 million people under home or hotel quarantine, the commission said.
The surge also comes exactly one month before China’s most important holiday, Lunar New Year, which in past years has seen so many people traveling home or on vacation that it is often called the world’s largest annual migration. Local authorities are encouraging reduced travel nationwide and outright preventing movement in several cities.
A team of experts led by the World Health Organization arrived on Thursday in Wuhan to investigate the origins of Covid-19, but without two members of the group who tested positive for coronavirus antibodies, the WHO said on Twitter.
For months China has been giving its still-experimental vaccines to frontline workers and at-risk citizens at home. Last month it officially approved one of its several candidate vaccines, produced by state-run
(1099:HK), which Beijing says is 79% effective based on late-stage data.
When asked at a press conference Wednesday if people in at-risk areas who have received the vaccine still need to isolate, Wang Bin, an official at the National Health Commission, said: “Most people have received only one dose, and therefore the protective effects of the vaccine will not be fully developed. Thus, the relevant local prevention and control requirements and regulations must be followed.”
China has 11 vaccine candidates at various research stages, according to the WHO’s tracking site. At least five of those are in Phase 3 trials, Chen Wei, a supervisor at China’s Academy of Military Medical Sciences, told Chinese media Wednesday.
Because of China’s dearth of its own coronavirus cases, many of those trials are running in foreign countries. One of the largest is in Brazil, where what had been seen as possibly the most promising candidate—Sinovac Biotech’s CoronaVac—recently produced Phase 3 results from a large sample population.
Last week Brazilian authorities said late-stage data showed it to be 78% effective in mild cases and 100% effective in moderate and severe cases. Critics were quick to ask why the company had remained silent on the data—with only the Brazilian government releasing information—and why the numbers had come out with little transparency and separate from those in Sinovac’s trials in other countries.
Those concerns seemed justified when Brazil on Tuesday said the inclusion of “very mild” cases lowered the effectiveness to 50.4% overall.
However, leading Brazilian infectious disease specialist, Marco Aurélio Safadi, said at a press conference Tuesday in Sao Paulo that the numbers remain in line with the country’s standard for acceptable vaccine efficacy, and the WHO has set 50% as its threshold for successful efficacy, which impacts its global approval process. By comparison, efficacy for the flu virus given in the U.S. each year normally ranges from 40% to 60%, according to the Centers for Disease Control.
Efficacy rates from Chinese vaccine trials in other countries have varied significantly. Turkey recently reported 91% efficacy rate from a relatively small sample size, and Indonesia, whose president was inoculated with CoronaVac Wednesday, previously reported a 65% effectiveness.
The problems plaguing Chinese vaccine makers may not be quality or efficacy—but rather transparency, Jerome H. Kim, director general of the International Vaccine Institute in Seoul, told Barron’s Wednesday. “China has a huge amount to contribute,” he said, including the capacity to make vaccines in large quantities and to produce types that do not require deep refrigeration. “Everyone wants this to work,” he said.
But Sinovac’s corporate silence, the lack of details on how its trials are run, and discrepancies in numbers of its reported samples sizes raise alarm bells, he said.
Kim said good science requires transparency. “If I were them I would hold a series of briefings and clarify everything,” he said.
Sinopharm is traded in Hong Kong, and its stock has been largely flat for most of the year. Sinovac is listed on the Nasdaq but its trading was halted in 2019 due to alleged shareholder infighting. Both companies declined to comment for this article.
Tanner Brown covers China for Barron’s and MarketWatch.