LONDON – A month ago, the pandemic looked bleak. In a single day, more than 750,000 cases of coronavirus were registered worldwide.
Infections increased across the United States. New variants identified in the United Kingdom, Brazil and South Africa threatened the rest of the world.
But in the last month there has been a Change of trend surprisingly fast, if partial.
People receive a dose of Sinovac Biotech’s COVID-19 vaccine at a Hong Kong community vaccination center. Photo Paul Yeung / Pool Photo via AP.
New cases have fallen to half their peak worldwide, largely driven by constant improvements in some of the same places that suffered devastating outbreaks this winter.
Cases are an imperfect measure, and uneven records and evidence mask the extent of the outbreaks, especially in parts of Africa, Latin America and South Asia.
However, there are fewer and fewer patients in hospitals in many countries with the highest rates of infection, leaving experts confident that the decline is real.
“It’s a great moment of optimism, but it’s also very fragile in many ways,” said Wafaa El-Sadr, an epidemiologist at Columbia University’s Mailman School of Public Health.
“We see the light at the end of the tunnelbut it’s still a long tunnel. “
The pause in many of the world’s worst outbreaks creates a critical opportunity to keep the virus in retreat as vaccines begin to take effect.
Experts believe vaccines have done little to curb most outbreaks so far, but a small group of countries, mainly wealthy ones, plan to vaccinate vulnerable groups by the spring.
Positive signals are accompanied by a series of warnings and risks.
Many countries continue to fight. Brazil it is fighting a serious outbreak in the face of a new variant discovered in the country.
Hospitalizations in Spain they are higher than ever, although official counts show a decline in new cases.
And in several European countries -the Czech Republic, Estonia and Slovakia– the infection rate is getting worse.
Nail most contagious variants – or simply a failure in social distancing and other control measures – could lead to new spikes in infections that could outweigh the positive effects of vaccination.
A variant first found in Britain it is spreading rapidly in the United States, and has been implicated in rallies in Ireland, Portugal and Jordan.
And while most countries have seen a decline in cases in the last month, the overall reduction globally has been largely driven by sonly six countries with huge epidemics.
There is no single cause for the decline, and the factors may be different in each location.
Public health experts in the most affected countries attribute the advances to a combination of greater social distancing and mask use, the seasonality of the virus and the accumulation of natural immunity among groups with high rates of existing infection.
Each factor may not be enough on its own.
It is believed that natural immunity, for example, it is far below the levels needed to stop the epidemic.
But the factors can combine to slow the rate of spread of the virus.
Though U.S did not impose a national shutdown, voluntary behavior changes, coupled with some degree of immunity in the hardest hit communities, may have helped prevent an even worse outcome after the holidays, said Caitlin Rivers, a public health researcher for the Johns Hopkins University.
“During the winter, when things really got worse, I think people saw how bad things were getting in their community and made different decisions,” Rivers said.
“They canceled meetings, stayed more at home, looked for the mask, and those things really help, together, to reduce transmission.”
The decline in South Africa has had many causes, but the main driver was the sheer intensity of the infection rate last month, said Marc Mendelson, head of HIV and infectious disease medicine at the University of Cape Town.
“At some point, the virus reaches a barrier, because it cannot find new people to infect, and it can no longer increase its transmission, “he said.
British experts attribute the decline to a strict national blockade launched after the holidays.
Vaccines don’t explain it: Although a quarter of the population has been vaccinated, only the first recipients had significant protection on January 10, when cases began to decline.
Those first doses were mostly for healthcare workers and older patients already in the hospital.
And some of the worst outbreaks in all of the Americas, southern Africa, and Europe peaked during or just after partiessaid El-Sadr, the Columbia University researcher.
“During these months there have been all these occasions for people to get together, mingle and travel with family and friends. I think that has probably driven that increase as well.”
The challenge of keeping infections at bay until vaccines take effect will be considerably greater in countries with slower vaccination schedules.
According to the World Health Organization, at the beginning of this month vaccination had not started in 130 countries, and more than three-quarters of the doses of vaccines administered have been applied in only 10 countries.
Many rich nations are hoarding doses, asking for enough to immunize their residents multiple times, while the poorest nations have yet to receive any.
And the South African finding that the AstraZeneca It had little effect on a fast-spreading variant and was another blow to countries that had planned to rely on the relatively cheap and easy-to-store vaccine as part of their deployment.
“We have just started our vaccination campaign in South Africa, and it’s going to be incredibly slow and it’s nowhere near where we wanted to be now, “Mendelson said.” For countries that have vaccines, the picture is slightly different. “
Experts believe that vaccines will play a critical role in reducing infections, preventing hospitalizations and deaths, and even reducing the possibility of future mutations if countries are able to vaccinate large swaths of their populations.
But the next period will be critical to avoid another wave of infections.
“We have a small window of opportunity to take advantage of the decline in the number of new infections,” said Bruno Ciancio, head of disease surveillance at the European Center for Disease Prevention and Control.
“We must continue with current public health measures and vaccinate as many people as possible.”
Allison McCann reported from London, Lauren Leatherby from New York and Josh Holder from Birmingham, England.
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