BY OSAMU TSUKIMORI, STAFF WRITER
Globally, there’s an intense race to secure COVID-19 vaccines, with many countries going to great lengths to curry favor with Beijing and Moscow to secure millions of doses to help overcome the pandemic.
As Western manufacturers struggle to meet demand for vaccines, Russia, China and India have been strategically donating or selling vaccines to dozens of countries to use them as diplomatic leverage.
China and India are ramping up coronavirus vaccine exports, as more than 15 countries have given regulatory approval for their vaccines for general use. The Chinese Olympic Committee has offered vaccines for Olympic and Paralympic participants in the Tokyo Games, but Chinese vaccines have not been granted approval for use in Japan.
China has approved five of its local COVID-19 vaccines so far, but none of the results of large clinical trials have been fully vetted, raising concerns about their efficacy globally.
For example, several countries that conducted clinical trials for a shot developed by Sinovac Biotech Ltd. have announced varying efficacy rates of between 50% to 84%, with none of the data peer reviewed in a medical journal. Data on the final overseas clinical trial conducted for the vaccine developed by Sinopharm has also not been published or peer reviewed.
“Chinese vaccine manufacturers could not complete a phase III clinical trial in China, as the number of infections there despite the large population was much smaller than those in Japan,” Dr. Hiroyuki Moriuchi, professor of pediatrics at Nagasaki University, said. “If a thousand participants receive a vaccine or placebo each in a randomized clinical trial with almost none of them having been infected, a successful phase III trial cannot be completed.”
Vaccines are given to healthy people, so it’s imperative to use vaccines that have cleared the necessary review process, including vetting evidence from clinical trials, he said.
“Chinese vaccines may turn out to be good ones but sadly no data has been released yet,” Moriuchi said. “Given the characteristics of the inactivated vaccines developed by Sinovac and Sinopharm, their efficacy is perhaps on par with the influenza vaccines at around 50% to 60%. It’s not bad, as we’re told every year that we must get an influenza shot.”
The same situation is seen for vaccines developed in India, as none of the results have been peer reviewed yet, he added.
India approved the Covaxin vaccine developed by a local drugmaker Bharat Biotech International Ltd. in January before efficacy data was released. The interim results released earlier this month for a clinical trial involving 25,800 participants showed an efficacy rate of 81% after the second dose. The company plans to submit the final analysis from the trial to a peer-reviewed journal for publication.
Russia’s Sputnik V vaccine, meanwhile, uses a harmless virus that delivers the genetic code needed to produce antibodies for the coronavirus. Developed by the state-run Gamaleya National Center of Epidemiology and Microbiology, the world’s first registered vaccine raised eyebrows across the globe last August when Moscow sanctioned its use without completing a large clinical trial.
But it was scientifically vindicated in February when British medical journal The Lancet published the interim results of a late-stage trial showing a notable 91.6% efficacy against the novel coronavirus, with complete protection against severe cases of the disease.
That was higher than the 82% efficacy rate after the second dose of the similar vaccine developed jointly by AstraZeneca PLC and Oxford University, according to the results of the late-stage clinical trial conducted in the U.K., Brazil and South Africa.
Moriuchi says the results of the final-phase clinical trial for Sputnik V that passed the journal’s stringent peer review process clearly show that the shot compares favorably with any Western vaccine.
“Sufficient data have been submitted, and there is no reason to doubt it,” said Moriuchi, who also serves as director of the Japanese Society for Virology. “Sputnik V is similar to AstraZeneca’s vaccine as they both use an adenovirus vector. It’s difficult to make a comparison, as the data on safety and effectiveness cannot be compared on a level playing field, but (Sputnik V) may be better than AstraZeneca’s vaccine.”
Amid a growing consensus that none of the vaccines developed by Japanese manufacturers are likely to get the official stamp of approval for use until 2022, the government may be forced to order additional doses to tide the country over until the 2022-23 winter season, as it remains unclear how long vaccine-induced immunity lasts. Some experts say that annual inoculations may be needed, just like the usual influenza shots that many people receive every year.
The government has so far signed contracts with AstraZeneca and U.S. pharmaceutical firms Pfizer Inc. and Moderna Inc. for a total of 314 million doses, more than enough to cover its entire 126 million population. All of these have been vetted and confirmed for their effectiveness and safety through large clinical trials overseas, with each involving at least tens of thousands of volunteers.
The obvious question is whether Japan will want to take advantage of the Russian vaccine, given that its safety and efficacy have been proven. It may also save money for the government, which set aside more than ¥670 billion for vaccines from the three Western firms.
The Sputnik V costs less than $10 (¥1,090) per shot, its Twitter account says. That is higher than the AstraZeneca vaccine, as the British firm has pledged to sell it at cost, but it is considered cheaper than vaccines such as Pfizer’s, which works in a different way and is said to cost closer to $20 per dose.
Still fresh in the memory of older people is that Japan imported millions of polio vaccines from the Soviet Union and Canada 60 years ago to inoculate children amid an epidemic without vetting the vaccine itself due to the emergency situation.
“Thousands of children a year lost their lives or became unable to live a normal life due to polio then, but the (Soviet) vaccine was excellent and cut the number of patients to virtually zero,” Moriuchi said. “Russia has strategically regarded vaccines as something to rely on when there’s bioterrorism, so the vaccine development capabilities of Russia are by nature very high.”
Russia is struggling to meet robust demand for Sputnik V, which is easier to store and transport than some other alternatives, as it can be stored at normal fridge temperatures. It has been authorized for use in more than 50 countries. In the face of slow distribution of vaccines and a mounting death toll in Europe, Hungary last month started administering the Russian shot, while Italy plans to produce the vaccine from July.
Russia has been courting Japan as well. The country’s ambassador to Japan, Mikhail Galuzin, revealed in a news conference earlier this month that the country has told the Japanese government that it is willing to export the vaccines, possibly along with a transfer of Sputnik V’s technology and production.
Taro Kono, the minister in charge of the vaccine rollout, however, indicated on a television program in mid-February that Japan is unlikely to take advantage of Russian and Chinese vaccines anytime soon.
“Unless in extreme circumstances, I’m thinking of going ahead with the three kinds” of vaccines, he said, referring to the three U.S. and U.K. firms that Japan has agreed to buy from.
A senior official at the Ministry of Health, Labor and Welfare said that Japan’s basic policy is to secure necessary volumes of vaccines if their safety and efficacy are likely to be confirmed through large clinical trials. The government will also take into consideration various things such as whether companies can conduct a clinical trial in Japan and make necessary filings for regulatory approval, he added.
“We would like to look broadly at the vaccines available on the market, not limiting it to those of the three firms,” said the official in charge of vaccine procurement. “But companies have to get regulatory approval in Japan for use here. For example, Moderna, which has no Japanese subsidiary, has partnered with Takeda Pharmaceutical Co. to make distribution in Japan possible. So we need to look at whether the vaccines made in Russia and China can secure approval in Japan.”
The government will also examine the benefits and the disadvantages of various vaccine types, health ministry officials said. The advantage of adenovirus vector vaccines such as those developed by Russia’s Gamaleya and AstraZeneca is that a single shot alone provides a high efficacy rate. New Jersey-based Johnson & Johnson’s single-shot vaccine, for example, which recently received approval from the U.S. and the European Union, was 66% effective with no hospitalizations or deaths reported during the late-stage clinical trial.
“An adenovirus vector vaccine would be best during the middle of the pandemic because it instantly gives you a high efficacy rate even after the first shot,” Moriuchi said.
But the drawback is that the repeated use of adenovirus vector vaccines results in reduced efficacy, as the immune system will produce antibodies targeting the adenovirus vector. In that respect, messenger RNA vaccines such as those made by Pfizer and Moderna have an advantage when it comes to repeated vaccinations, he added, though their disadvantage is that they are slightly likelier to cause cases of severe allergic reactions called anaphylaxis.
Japanese vaccine manufacturers face hurdles to approval and production, as daily infections have slowed from their peak during the third wave this winter. They are looking at conducting large clinical trials overseas instead, but another difficulty they’ll face is enrolling participants in the clinical trials, as effective vaccines have already entered the market.
“So far it is unlikely that Japanese vaccines will be developed in time for the next winter, but I hope they will be made available for use before the following winter,” Moriuchi said.