World

The pandemic is receding in the worst hot spots. Will it last?


Sep 1

October 1st

November 1

Dec 1

January 1st

February 20

400,000

600,000 cases

Rest of the world

Europe

United Kingdom

United States

South Africa

Brazil

January 11

Average number of new cases per day

LONDON – A month ago the pandemic looked grim. More than 750,000 cases of coronavirus have been recorded worldwide in a single day. Infections have jumped across the United States. New variants identified in the UK, Brazil and South Africa threatened the rest of the world.

But the past month has brought a surprisingly rapid, albeit partial, turnaround. New cases have halved at their peak globally, largely thanks to steady improvements in some of the same places that have weathered devastating epidemics this winter.

Cases are an imperfect measure, and uneven recording and testing hide scope epidemics, especially in parts of Africa, Latin America and South Asia. But fewer patients are presenting to hospitals in many countries with the highest infection rates, giving experts confidence the drop is real.

“It’s a great moment of optimism, but it’s also very fragile in many ways,” said Wafaa El-Sadr, epidemiologist at Columbia University’s Mailman School of Public Health. “We see the light at the end of the tunnel, but it’s still a long tunnel.”

How cases have changed in countries where outbreaks are greatest

New cases per 100,000 population, seven-day average. Grouped by percentage change over the past 28 days

Cases have dramatically decreased 28 countries

Cases declined in 17 countries

Flat case in ten countries

Cases have increased in 23 countries

Note: Percentage change is calculated from the rate 28 days ago. Includes only countries that have experienced epidemics of more than 10 cases per 100,000 population since October 1 and have a population of more than one million people.

The appeasement of many of the world’s worst epidemics creates a crucial opportunity to keep the virus on the decline as vaccinations begin to take effect. Experts say vaccines have done little to slow most outbreaks so far, but a small group of countries, mainly the rich, plan to vaccinate vulnerable groups by spring.

With the positive signs come a number of caveats and risks.

Many countries are still struggling. Brazil is fight a serious resurgence facing a new variant discovered in the country. Hospitalizations in Spain are higher than they have ever been, although official counts show a drop in new cases. And in a number of European countries – the Czech Republic, Estonia and Slovakia – the infection rate is worsening.

More contagious variants – or simply loopholes in social distancing and other control measures – could still lead to new spikes in infections that could outweigh the positive effects of the vaccination. A variant first found in Britain is spread quickly in the United States, and he’s been involved in outbreaks in Ireland, Portugal, and Jordan.

And while most countries have seen a drop in cases over the past month, the overall overall reduction has been largely attributable to just six countries with huge epidemics.

Six countries account for most of the global reduction in new cases

Reduction in new cases since January 11

400,000300,000200,000100,000 fewer casesJanuary 11February 20United StatesUnited KingdomSouth AfricaBrazilGermanyColombiaRest of the world183,000 fewer cases97,000 fewer cases

Note: Cases are presented as seven-day averages.

There is no single cause behind the slowdowns and the factors can differ in different locations. Public health experts in worst-affected countries attribute progress a combination from increased adherence to social distancing and mask-wearing, seasonality of the virus, and a build-up of natural immunity among groups with high rates of existing infection.

Each factor may not be sufficient on its own. Natural immunity, for example, would be well below the levels needed to stop the epidemic. But the factors can combine to slow the speed of the virus spread.

While the United States has not imposed a national lockdown, voluntary behavior changes, along with a degree of immunity in hard-hit communities, may have helped prevent an even worse outcome after the holidays, a said Caitlin Rivers, epidemiologist at Johns Hopkins University. .

“During the winter when things were really bad, I think people saw how bad things were in their community and made different choices,” said Dr. Rivers. “They canceled gatherings, they stayed more at home, they looked for the mask, and these things are really helping, to set up, to reduce transmission.

The decline in South Africa has had many causes, but the main driver has been the sheer intensity of the infection rate last month, said Marc Mendelson, head of infectious diseases and HIV medicine at the University of the Cap.

“At some point, the virus hits a barrier because it cannot find new people to infect, and it cannot continue to increase its transmission,” he said.

British experts attribute the decline to a strict national lockdown set up after the holiday season. Vaccines do not explain it: even if a quarter of the population has been vaccinated, only the first beneficiaries had significant protection on January 10, when cases started to decline. These first doses were mainly intended for health workers and elderly patients already in hospital.

And some of the worst epidemics across the Americas, southern Africa and Europe peaked during or just after the holidays, said Dr. El-Sadr, a researcher at Columbia University. “In those few months, there have been all these opportunities for people to mingle, mingle and travel with their family and friends. I think that’s probably the source of this surge as well.

The challenge of limiting infections until vaccines take effect will be considerably greater in countries with slower vaccination programs.

Vaccinations had not started at all in 130 countries as of the start of this month, according to the World Health Organization, and more than three-quarters of the vaccine doses given were in just 10 countries. Many rich countries accumulate doses, ordering enough to vaccinate their residents several times, while poorer nations have yet to receive any.

And a discovery from South Africa that the AstraZeneca vaccine had little effect on a fast release variant dealt another blow to countries that had planned to rely on the relatively cheap and easy to store vaccine as part of their deployment.

“We are just starting our vaccination campaign in South Africa, and it is going to be incredibly slow and far from where we wanted to be right now,” said Dr Mendelson. “For countries that have vaccines, it’s a slightly different landscape.”

Experts believe vaccines will play a critical role in reducing infections, preventing hospitalizations and deaths, and even reducing risk future changes whether countries are able to immunize large sections of their populations. But the next period will be crucial to avoid a new wave of infection.

“Here we have a small window of opportunity to take advantage of the decrease in the number of new infections,” said Bruno Ciancio, head of disease surveillance at the European Center for disease prevention and control. “We need to continue with the public health measures in place and vaccinate as many people as possible.”


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