Thursday, October 07, 2021

Incredible Covid trend in Japan baffles experts as cases suddenly plummet

I think I have a fair idea of what is going on. Delta is highly infective but only for a minority of people. So once it has infected them it dies out

Despite our enjoyment of the Olympics from afar, there was a debate around whether or not the games should have gone ahead, given what was happening in Japan at the time.

The nation of 125 million had done reasonably well for a country of its size and population density before then, keeping Covid cases relatively under control and preventing deaths from the virus.

But then, almost in tandem with Australia, things started to head south in July with the introduction of the Delta strain.

It was terrible timing for Japan, with the Olympics about to bring athletes and dignitaries from all around the world into the country just as cases began to take off.

Many residents and health experts wanted the games to be called off.

Things were not looking good after athletes returned home either, as infections kept rising.

By the end of August, Japan — which has the world’s third largest economy — was clocking up more than 24,000 cases a day. Deaths began to climb too, with the seven-day average hovering around 50-60 for several weeks.

However, something truly remarkable has happened since then, and experts around the world can’t believe what they are seeing.

As other parts of Asia are seeing their cases rise, infections in Japan have plummeted to their lowest levels in nearly a year.

New daily cases in Tokyo dropped to just 87 on Monday, the city’s lowest tally since November 2 last year and a massive decline from the thousands of new cases each day seen just a matter of weeks ago.

Other cities around the nation are seeing the same trend, with the average number of daily new infections falling by more than 8000 in the past three weeks.

Experts scratching their heads

The huge decline in cases is obviously welcome news to everyday Japanese residents, but the reasons behind it are leaving experts around the world perplexed.

Professor Mark Woolhouse, epidemiologist at the University of Edinburgh, said the plunge was probably because the Delta variant appears to “move faster through populations”.

“Spikes for the Delta variant tend to be spikier. They go up faster, and they come down faster,” he told the UK’s inews.

Although the drop in cases itself is not a “particular surprise”, cases have come down “fast”, he said.

“We first saw that in the first wave of Delta which hit India and that had the same characteristic; it went up very fast, and it came down very fast,” he said.

He added that is because the Delta variant has a shorter “generation time”, meaning how long it takes one infected person to infect another.

He and government experts in Japan have put the drop in cases largely down to vaccinations and recent restrictions linked to the state of emergency.

Much of Japan has been under virus emergency measures for a large part of the year, with the restrictions finally lifting last week due to the decline in infections.

Other experts, like Kyoto University’s Hiroshi Nishiura, say the recent spike in cases has ended because of changes in the flow of people, with fewer travellers now holidaying and socialising in Japan.

Mr Nishiura believes infectivity, as measured by the effective reproduction number, is correlated with holiday breaks.

“During the holidays, we meet persons whom we seldom meet up with, and moreover, there is a substantial chance to eat together in a face-to-face environment,” Mr Nishiura, a top infectious disease modeller advising the government, told Reuters.

He said recent record cases in South Korea and Singapore may be connected to some mid-year holidays, and a convergence of Asian and Western holidays at the end of the year could lead to a “nightmare”.

Another school of thought is that the virus comes in vicious cycles, fuelled by one particular age demographic.

Jason Tetro, a Canada-based infectious disease expert and author of The Germ Code, said different age cohorts become “fuel” for the virus to spread, depending on vaccination rates and prior infections, at different times.

“Without elimination of the virus, we will continue to see spikes until 85 per cent of the population is immune to the dominant strain,” he told Reuters.
“This is the only way to get out of these vicious cycles.”

Another theory is that Covid-19 and its variants tend to move in two-month cycles, though Mr Tetro argued the cycles were “more a factor of human nature than mother nature”.

Fears as Japan heads into winter

Although cases have dropped significantly, there are fears of another wave as the nation heads into winter.

More than 60 per cent of the population is now fully vaccinated, but there are concerns that the healthcare system could easily become overwhelmed again, should a new wave emerge.

Japan’s vaccination rollout was initially slow compared to other G7 nations. Frontline health care workers were jabbed on February 17, but the rollout to older people did not start until late April.

However, Japan picked up quickly and now more than 158 million doses have been administered, with 63.5 per cent of people aged 12 and over double jabbed. That’s 57 per cent of the total population.


Pfizer and Moderna Covid vaccines were 95% effective against infection and 91% against hospitalization among US veterans - with NO deaths, study finds

Data from early this year

COVID-19 vaccines are effective at preventing infections and hospitalizations among U.S. veterans, a new study finds.

Researchers from the Department of Veterans Affairs and the Food and Drug Administration looked at data from the first three months of the shots' availability.

They found that the Pfizer-BioNTech and Moderna vaccines had an efficacy of 95 percent against infection and were 91 percent effective at preventing hospitalization.

There were also no deaths among fully vaccinated veterans.

The team says the findings shows how protective the vaccines were early on in the roll out and why it was so important to get veterans - who are a population at increased risk of severe Covid - immunized quickly.

Researchers gathered data from 6.6 million veterans between December 2020 to March 2021. They found that 1.3 million - almost one out of every five - received at least one shot of a COVID-19 vaccine during that period.

Older veterans were more likely to have received the shots at this point than their younger counterparts, though researchers found little difference in vaccination rates across racial lines.

At the time, the Covid vaccines were not available to all Americans, but instead only to certain groups depending on what state someone live in.

Seniors were prioritized in basically every state - which is why older veterans had better vaccine coverage - but veterans with certain comorbidities or who were front line workers were eligible in some states as well.

More than 472,000 participants in the study had tested for COVID-19 at some point during the study period, with 15,000 positive cases being detected.

Of the positive cases, 41 were breakthrough cases detected in fully vaccinated people, 270 were in partially vaccinated veterans and 14,799 were among the unvaccinated.

Researchers, who published their findings in JAMA Network Open on Wednesday, found that only 22.8 out of every 100,000 participants who were at least partially vaccinated in the study contracted Covid.

The rate of infection is more than ten-fold for the unvaccinated, with 280 out of every 100,000 people contracting the virus.

When adjusting for other factors, such as age, race and geography, researchers found that the vaccine is 95 percent effective at preventing infection, and 91 percent effective at preventing hospitalization.

There were also no COVID-19 deaths among fully vaccinated participants in the study.

Partial vaccination - meaning receiving only one shot of a two-dose series - still provides protection as well with 64 percent vaccine effectiveness against infection.

One shot was also 48 percent effective at preventing hospitalization and 63 percent effective at preventing deaths, the researchers found.

While the results of the study do capture the initial effectiveness of the Moderna and Pfizer-BioNTech vaccines, the situation in America has changed since data was captured.

The Delta variant, a highly contagious strain of the virus that caused a massive surge of cases in the U.S. over the summer, had not yet reached the nation in March.

More recent data also shows that the vaccine's effectiveness at preventing infection does wane over time, meaning the earliest adopters of the shots - who would be among those vaccinated seven months ago - will not be as protected now as they were then.

In order to combat the waning effectiveness, booster shots have been made available to people over the age of 65 or with comorbidities that put them at serious risk from the virus.

Currently in the U.S., 65 percent of people have received at least one dose of a COVID-19 vaccine and 56 percent of residents are fully vaccinated.

Just over six million booster doses have been administered as well, according to official data.




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