Japanese researchers say the country’s COVID-19 vaccination program has a long way to go to reduce the number of infections and deaths.
An organization at Kyoto University led by Professor Nishiura Hiroshi published its assessment in the foreign clinical journal Scientific Reports.
Using a mathematical model, the researchers simulated the number of coronavirus infections and deaths in the absence of vaccination over a 10-month period in February 2021, when inoculation began.
The simulation was based on the assumption that the actual number of infections, adding asymptomatic cases, is 4 times higher than the number of cases shown.
The researchers also took into account people’s movements, the characteristics of coronavirus variants, and points to expand a transmission model.
The researchers say that in the absence of vaccination, the cumulative number of infections and deaths during the time would have been 63. 3 million and 364,000, respectively.
The numbers of infections and deaths were 4. 7 million and 10,000, respectively.
They say the vaccines’ maximum efficacy is likely due to the herd immunity achieved through the vaccine rollout, as you can catch the virus from other unvaccinated people.
Professor Nishiura says that through this method, the government can implement a vaccination program based on real-time observations of the vaccine’s effectiveness.
Inaba Hisashi, an assigned professor at Tokyo’s Gakugei University, says it’s highly unlikely that it would be possible to practice what the infection scenario would have been without vaccines.
But he says the mathematical-style simulation suggests that the vaccination program had significant spillover effects.
Inaba says there is no set approach to assessing the actual effectiveness of vaccination at the population level. He says the researchers want to continue investigating and that there are other points to consider.