Could the world soon kiss the coronavirus goodbye and return to the good old days before the pandemic?
The news that experimental COVID-19 vaccines produced by U.S. drugmakers Pfizer Inc. and Moderna Inc. were about 95% effective in late-stage trials helped push up global stock markets and offered a ray of hope around the globe.
But not so fast, say some medical experts in Japan.
Masayuki Miyasaka, professor emeritus of immunology at Osaka University, said in a Lower House committee meeting last week that the vaccines being developed by Pfizer and Moderna look to be highly effective. The two pharmaceutical companies say their interim analysis of the late-stage trials reported no serious safety concerns.
But Miyasaka, nevertheless, voiced worries about their safety over the long term.
“Vaccines usually take 10 years or more to develop, but the world is racing to develop COVID-19 vaccines in just a year,” he said.
Pfizer, for example, says it conducted the late-stage trials in the U.S. and five other countries. The European Union and the U.S. have a “mutual recognition agreement,” which allows the drugs to be used within each other’s borders to avoid the duplication of clinical trials.
But Japan, which is one of the very few countries that require additional clinical trials within the country to ensure safety, could have difficulty conducting a successful late-stage trial. The recent rate of infections in Tokyo was estimated at only several out of 1,000 people, which might be too low to make a valid assessment in a late-stage trial in Japan to replicate the high efficacy of the vaccines confirmed overseas, Miyasaka said.
That would mean the country may need to skip the late-stage trials, which Japan has done in the past. But skipping the trials — or relying only on the results of overseas trials — could have severe consequences, experts say.
Japan approved the Arava rheumatoid arthritis drug in 2003 without conducting a late-stage trial in the country. The drug was administered to around 5,000 patients but 25 of them died, Miyasaka said. It was later found that the dosage should have been lower in Japan than it was overseas, he said.
“My conclusions are that the efficacy (of those drugs) should be high, but safety has not been guaranteed, and we have to treat them with extreme caution,” he said.
Because of the possible side effects, Miyasaka said people should have the choice of whether they would get a shot.
“Only those who wish to have vaccinations should do so. It’s highly questionable to prioritize medical workers (for vaccinations). Individual wishes should be respected.”
His comments are in sharp contrast to those of Dr. Anthony Fauci, the top U.S. infectious disease expert and a member of the White House coronavirus task force, who said the vaccines under development by Moderna and Pfizer are “extraordinarily impressive” and brushed aside concerns about the speed of development.
“The process of the speed did not compromise at all safety, nor did it compromise scientific integrity,” Fauci said during a briefing at the White House last Thursday. “It was a reflection of the extraordinary scientific advances in these types of vaccines, which allowed us to do things in months that actually took years before. So I really want to settle that concern that people have about that.”
Last Thursday, the Lower House approved a bill to provide vaccinations to all residents for free and allow the government to shoulder any liability damages for the pharmaceutical companies.
The health ministry plans to prioritize vaccinations for the elderly, followed by those with chronic diseases, when the vaccines become available.
Older people are at least a dozen times more likely to develop severe complications compared with healthy adults, while those suffering from heart or chronic lung illness, cerebrovascular disease or renal dysfunction face risks a few times higher, according to the ministry.
Although the bill stipulates that efforts should be made to vaccinate residents, Chief Cabinet Secretary Katsunobu Kato has said that it’s ultimately up to the individuals whether to get the shot considering there are potential side effects.
Dr. Tetsuo Nakayama, a project professor at Kitasato Institute for Life Sciences and director of the Japanese Society of Clinical Virology, says although the vaccines under development by Pfizer and Moderna successfully created antibodies in trials, there are still doubts about whether those antibodies remain a year or two after vaccination.
There are also underlying concerns about the vaccines’ safety over the long term. Judging from past precedents, their safety and effectiveness are not something that can be determined until at least a year after a massive number of vaccinations have been administered, experts say.
In a worst-case scenario, antibodies could worsen the disease by essentially helping the infection of cells — a phenomenon called antibody dependent enhancement (ADE) — rather than fighting the virus pathogens.
For example, a dengue fever vaccine made by Sanofi, based on a yellow fever vaccine embedded with a part of the dengue virus genome, at first appeared to be effective. But it caused the deaths of children who had been given the vaccination due to the ADE phenomenon.
“Concerns over ADE still remain. I am an elderly person myself, but if I were asked, I would say I don’t want to get a shot,” Nakayama said. “Not all of the 120 million people (in Japan) should get the vaccinations. Children, for example, would not need it because there’s scarcely any risk of severe cases.”
Pfizer said that its COVID-19 vaccine under development could obtain emergency U.S. and European authorization next month, saying that its final trial confirmed no serious side effects.
So far, the Japanese government has signed an agreement to receive 120 million doses, enough to inoculate 60 million people, from Pfizer by the end of June. It also would receive 50 million doses, which could cover 25 million people, of Moderna’s vaccine from Takeda Pharmaceuticals Co. by the end of September.
Some medical professionals say that society needs to take a hard look at the fact that the majority of people getting infected with the coronavirus only experience minor symptoms, with there being a relatively low chance of developing a severe condition or dying.
“The U.S. and Europe put priority on the vaccine’s effectiveness first, followed by the side effects, in a bid to reduce the number of infections amid the pandemic, but the Japanese have a tendency to worry about both effectiveness and safety,” Nakayama added.
More than 500,000 people have died in the U.S. and Europe, but Japan’s total death toll has been much smaller, at around 2,000.
“The development of drugs should come first, to make people feel at ease in the event they get infected,” he said.
A treatment for the disease would be a game-changer. Fujifilm Holdings Corp. last month filed an application with the health ministry to have its anti-influenza drug Avigan approved for treating COVID-19.
“We still don’t have established therapeutics yet to cure COVID-19, but if medicine that could be used for mild symptoms like Avigan were approved, it could change the situation,” Nakayama said.
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