When the coronavirus pandemic took hold in India, there were fears it would sink the fragile health system of the world바카라s second-most populous country. Infections climbed dramatically for months and at one point India looked like it might overtake the United Statesas the country with the highest case toll.
But infections began to plummet in September, and now the country is reporting about 11,000 new cases a day, compared to a peak of nearly 100,000, leaving experts perplexed.
They have suggested many possible explanations for the sudden drop 바카라 seen in almost every region 바카라 including that some areas of the country may have reached herd immunity or that Indians may have some preexisting protection from the virus.
The Indian government has also partly attributed the dip in cases to mask-wearing, which is mandatory in public in India and violations draw hefty fines in some cities. But experts have noted the situation is more complicated since the decline is uniform even though mask compliance is flagging in some areas.
It바카라s more than just an intriguing puzzle; determining what바카라s behind the drop in infections could help authorities control the virus in the country, which has reported nearly 11 million cases and over 155,000 deaths. Some 2.4 million people have died worldwide.
바카라If we don바카라t know the reason, you could unknowingly be doing things that could lead to a flare-up,바카라 said Dr Shahid Jameel, who studies viruses at India바카라s Ashoka University.
India, like other countries, misses many infections, and there are questions about how it바카라s counting virus deaths. But the strain on the country바카라s hospitals has also declined in recent weeks, a further indication the virus바카라s spread is slowing. When recorded cases crossed 9 million in November, official figures showed nearly 90% of all critical care beds with ventilators in New Delhi were full. On Thursday, 16% of these beds were occupied.
That success can바카라t be attributed to vaccinations since India only began administering shots in January 바카라 but as more people get a vaccine, the outlook should look even better, though experts are also concerned about variants identified in many countries that appear to be more contagious and render some treatments and vaccines less effective.
Among the possible explanations for the fall in cases is that some large areas have reached herd immunity 바카라 the threshold at which enough people have developed immunity to the virus, by falling sick or being vaccinated, that the spread begins to slacken, said Vineeta Bal, who studies immune systems at India바카라s National Institute of Immunology.
But experts have cautioned that even if herd immunity in some places is partially responsible for the decline, the population as a whole remains vulnerable 바카라 and must continue to take precautions.
This is especially true because new research suggests that people who got sick with one form of the virus may be able to get infected again with a new version. Bal, for instance, pointed to a recent survey in Manaus, Brazil, that estimated that over 75% of people there had antibodies for the virus in October 바카라 before cases surged again in January.
바카라I don바카라t think anyone has the final answer,바카라 she said.
And, in India, the data is not as dramatic. A nationwide screening for antibodies by Indian health agencies estimated that about 270 million, or one in five Indians, had been infected by the virus before vaccinations started 바카라 that바카라s far below the rate of 70% or higher that experts say might be the threshold for the coronavirus, though even that is not certain.
바카라The message is that a large proportion of the population remains vulnerable,바카라 said Dr. Balram Bhargava, who heads India바카라s premier medical research body, the Indian Council of Medical Research.
But the survey offered other insight into why India바카라s infections might be falling. It showed that more people had been infected in India바카라s cities than in its villages, and that the virus was moving more slowly through the rural hinterland.
바카라Rural areas have lesser crowd density, people work in open spaces more and homes are much more ventilated,바카라 said Dr. K. Srinath Reddy, president of the Public Health Foundation of India.
If some urban areas are moving closer to herd immunity 바카라 wherever that threshold lies 바카라 and are also limiting transmission through masks and physical distancing and thus are seeing falling cases, then maybe the low speed at which the virus is passing through rural India can help explain sinking numbers, suggested Reddy.
Another possibility is that many Indians are exposed to a variety of diseases throughout their lives 바카라 cholera, typhoid and tuberculosis, for instance, are prevalent 바카라 and this exposure can prime the body to mount a stronger, initial immune response to a new virus.
바카라If the COVID virus can be controlled in the nose and throat, before it reaches the lungs, it doesn바카라t become as serious. Innate immunity works at this level, by trying to reduce the viral infection and stop it from getting to the lungs,바카라 said Jameel, of Ashoka University.
Despite the good news in India, the rise of new variants has added another challenge to efforts here and around the globe to bring the pandemic under control. Scientists have identified several variants in India, including some that have been blamed for causing new infections in people who already had an earlier version of the virus. But they are still studying the public health implications.
Experts are considering if variants may be driving a surge in cases in the southern state of Kerala, which had previously been hailed as a blueprint for tackling the virus. Kerala now accounts for nearly half of India바카라s current COVID-19 cases. Government-funded research has suggested that a more contagious version of the virus could be at play, and efforts to sequence its genome are ongoing.
With the reasons behind India바카라s success unclear, experts are concerned that people will let down their guard. Large parts of India have already returned to normal life. In many cities, markets are heaving, roads are crowded and restaurants nearly full.
바카라With the reducing numbers, I feel that the worst of COVID is over,바카라 said M. B. Ravikumar, an architect who was hospitalized last year and recovered. 바카라And we can all breathe a sigh of relief.바카라
Maybe not yet, said Jishnu Das, a health economist at Georgetown University who advises the West Bengal state on handling the pandemic.
바카라We don바카라t know if this will come back after three to four months,바카라 he warned.
The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute바카라s Department of Science Education. The AP is solely responsible for all content.
