- A month ago, the pandemic looked bleak. More than 750,000 coronavirus cases were tallied worldwide in a single day. Infections surged across the entire United States. New variants identified in the United Kingdom, Brazil and South Africa threatened the rest of the world.
- But the last month has brought a surprisingly fast, if partial, turnaround. New cases have declined to half their peak globally, driven largely by steady improvements in some of the same places that weathered devastating outbreaks this winter.
- Cases are an imperfect measure, and uneven records and testing mask the scope of outbreaks, especially in parts of Africa, Latin America and South Asia. But fewer patients are showing up at hospitals in many countries with the highest rates of infection, giving experts confidence that the decline is real.
- Many countries are still struggling. Brazil is battling a serious resurgence in the face of a new variant discovered in the country. Hospitalizations in Spain are higher than they’ve ever been, even though official tallies show a decline in new cases. And in a number of European countries — the Czech Republic, Estonia and Slovakia — the infection rate is worsening.
- There is no single cause behind the slowdowns, and the factors may differ in different places. Public health experts in the worst-hit countries attribute the progress to some combination of increased adherence to social distancing and mask wearing, the seasonality of the virus and a buildup of natural immunity among groups with high rates of existing infection.
- Each factor may not be enough on its own. Natural immunity, for instance, is believed to be well short of levels required to stop the epidemic. But the factors can combine to slow the rate at which the virus spreads.
- 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, the head of infectious disease and HIV medicine at the University of Cape Town.
- The challenge of keeping infections down until vaccines take effect will be considerably greater in countries with slower vaccination programs.
- Vaccinations had not begun at all in 130 countries as of early this month, according to the World Health Organization, and more than three-quarters of the vaccine doses administered have been in just 10 countries. Many rich nations are hoarding doses, ordering enough to immunize their residents multiple times over, while poorer nations have yet to receive any.
- Experts believe that vaccines will play a critical role in keeping infections down, preventing hospitalizations and deaths and even reducing the chance 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 infection.
- “We have a small window of opportunity here to take advantage of the decreasing number of new infections,” said Bruno Ciancio, the head of disease surveillance at the European Center for Disease Prevention and Control. “We must continue with the public health measures in place and vaccinate as many people as possible.”