Japanese drugmaker Shionogi & Co. has sealed a deal to conduct a placebo-controlled trial of its COVID-19 vaccine in Vietnam and will be expanding it in the Philippines and other Southeast Asian countries, even as criticism of such tests mounts in the scientific community.
The Osaka-based company began testing the efficacy of its shot in Vietnam from Dec. 25, a spokesman at Shionogi said Monday. Participants of the trial, which will eventually total 50,000 volunteers, need to be unvaccinated, the spokesman said, with two-thirds of them receiving the inoculation and others getting a placebo. The company is also planning to analyze whether it’s effective against the omicron strain, the spokesman added.
Vaccine developers only bringing shots to the testing phase now are finding it an uphill battle, with the developed world so highly vaccinated and already moving on to booster shots. That’s left companies such as Shionogi and Chinese pharmaceutical makers such as Walvax Biotechnology Co. and Xiamen Innovax Biotech Co. seeking out developing nations where vaccination rates remain low and the virus is still active.
"This is our last chance” to run a trial that evaluates the true end point of a vaccine, Shionogi President and Chief Executive Officer Isao Teshirogi said at a briefing on Nov. 1. "Only those that proved to have prevented the onset of COVID-19 can make the WHO’s vaccine list.”
Vietnam in many ways is an ideal target, given its ongoing struggle with COVID-19, even as other parts of Southeast Asia emerge from the pandemic. Vietnam has vaccinated about 64% of its population, according to the Bloomberg Vaccine Tracker.
While Shionogi has agreed to transfer vaccine-production technology to Vietnam so that it can make doses for its citizens locally, some scientists argue that conducting placebo-controlled trials in places where vaccines aren’t sufficiently available is unethical and possibly exploitative. Shionogi shares are up 45% this year.
"The scarcity of vaccines in most countries is created by the rich nations that have hoarded vaccines,” Aasim Ahmad and Murtaza F. Dhrolia, nephrologists at the Kidney Center in Pakistan, wrote in a study earlier this year. "There are valid scientific methods like non-inferiority trials which can give reliable results, and that applying a standard of care imposed by rich nations is both unethical and possibly exploitative.”
The World Health Organization, however, has said the trials in general are justified, provided their risk-benefit profile is acceptable.
The escalation in infections has disrupted Vietnam’s supply chains, exacerbating the vaccine shortage despite it receiving millions of doses from countries including the U.S. and China. It’s not alone in the developing world, as less than half of the global population has been fully immunized, compared with around 80% among G7 countries, according to figures from Our World in Data. Just five African countries including the Seychelles, Mauritius and Morocco are projected to hit a year-end target of fully vaccinating 40% of their people and the limited access to syringes may slow the rollout, the World Health Organization said in October.
China’s Walvax is testing its mRNA candidate in placebo-controlled trials in Mexico and Indonesia, where vaccination rates for the first dose are below 60% and 64% respectively.
In an interview in September, Walvax vice-chairman Huang Zhen said some governments are already reluctant to approve requests from companies to run trials that involve some participants not receiving a vaccine. Walvax found it tough to secure regulatory sign-offs due to the pressure of such trials, Huang said.
Xiamen Innovax got approval to run a placebo-controlled trial in South Africa, where the new omicron variant emerged. The company has indicated that some of its other trial sites may have to benchmark a new shot against an existing one, given the difficulties with placebo-based studies.
Shionogi and Daiichi Sankyo Co. are also preparing to conduct those sorts of trials in Japan, where more than 75% of the population is already inoculated with existing vaccines, mostly with Pfizer Inc. and Moderna Inc. from the U.S.
Shionogi is planning to file the vaccine for a regulatory review in Japan by end of March 2022, it said in a statement on Monday. While the launch in the domestic market is the priority, it’s also considering seeking its use in other markets.
"Even now, the supply of vaccines is insufficient in many countries and regions,” Shionogi said. "We will conduct this trial with an eye on future contribution to global health.”
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