New coronavirus vaccines are seen as crucial for the protracted launch of the Tokyo Olympics and Paralympics less than a year away. But a number of research studies are showing people infected with COVID-19 have lost their immunity to the infection within a few months, casting a shadow over Japan’s hopes to give a much-needed shot in the arm to its battered economy.
The research has poured cold water on the optimism of vaccine manufacturers who have been working around the clock to produce mass vaccinations that boost antibodies in people against the disease.
Still, experts say that it may not be as bad as it seems. A King’s College London study of more than 90 people infected with COVID-19 showed that the levels of antibodies peaked three weeks after the onset of symptoms, and then declined rapidly. Only about 16.7 percent of them had elevated levels of antibodies three months later. Similar findings have been reported in Spain as well.
“Antibody levels for asymptomatic individuals are low, and the antibodies in people with no or mild symptoms do not last long,” Dr. Tetsuo Nakayama, a project professor at Kitasato Institute for Life Sciences and director of the Japanese Society of Clinical Virology, said.
Dr. Barry Bloom, a professor at Harvard School of Public Health, says the data from many countries indicate that SARS-CoV-2 antibodies in patients tend to decline more rapidly than in other virus infections. “They last for sure for several months and some may last a lot longer.”
For the original global severe acute respiratory syndrome (SARS) outbreak in 2002-2003, some people had antibodies 18 years later, Bloom added.
It remains unclear what antibody level is sufficient to ensure protection, but even a slight amount of neutralizing antibodies could be protective, Bloom said.
The situation does not seem to be as bad as many fear thanks to our powerful immune system composed of T cells in the blood that bind to and kill infected cells — with the aid of B cells that produce antibodies — based on memory from past infections.
“T cells carry immunologic memory and the reintroduction of the virus could stimulate a memory response leading to rapid production of antibodies,” Bloom said.
There are many questions surrounding the effectiveness and efficacy of the vaccines in preventing the coronavirus disease, but a team of scientists at Oxford University said the results of Phase I-2 trials showed that the vaccine it is developing with U.K. biopharmaceutical firm AstraZeneca provoked a T cell response within 14 days of vaccination and an antibody response within 28 days.
“We saw the strongest immune response in the 10 participants who received two doses of the vaccine, indicating that this might be a good strategy for vaccination,” Professor Andrew Pollard, chief investigator for the University of Oxford COVID-19 vaccine study, said.
The vaccines would hopefully pave the way for getting the world’s economy back on a normal footing and for Japan to be able to host the Olympic Games next year, Nakayama said. But that’s not easy to accomplish in such a short time frame as long-term follow-up studies are needed to see whether people who have received inoculations against the disease experience severe COVID-19 symptoms down the road a few years later.
“The successful creation of antibodies through a booster shot of the vaccines and reports of no side effects alone are not enough to provide comfort,” he said.
The outlook over Tokyo’s successful holding of the Olympics hinges on the vaccines, but it remains unclear how long it would take for manufacturers to make the five billion doses to protect all the people at risk globally, Bloom said.
“One can hope the pandemic will be controlled by summer of 2021 but that is not certain at this time,” he added.
One ray of hope for Tokyo is the news of Russia’s approval of the world’s first vaccine against the new coronavirus, which could help spur the development of many more vaccines around the world. Still, Moscow’s move has raised eyebrows as the approval came “without full and rigorous safety and efficacy trials,” Bloom added.
“There are concerns that to come in first, the Russian authorities approved a vaccine without the necessary trial data,” he said. “It is a recombinant of two adenovirus strains so there is no reason to believe it might not be effective and safe, but there needs to be real data.”
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