Although attention has focused on the worrying new variants of SARS-CoV-2, there has been some good news: despite the evolution of a series of strains that appear to spread more readily, the total number of COVID-19 cases has declined, both in the United States and globally. Although there are several nations that still see an increase in infections, a combination of reduced post-holiday spread and increased social interventions appears to be controlling the outbreaks seen in January.
That said, there are worrying signs that, at least in the United States, several states are making the same mistakes that ensured that the virus never really left after the first spike in cases. And the spread of many new variants shows the need to avoid complacency.
Going down
The general drop in cases occurred at a recent World Health Organization press conference. “For the third week in a row, the number of new COVID-19 cases reported globally dropped last week,” said WHO Director-General Tedros Adhanom Ghebreyesus. “There are still many countries with increasing numbers of cases, but globally, this is encouraging news.”
The United States is part of this trend. In the states, cases peaked in mid-January and have been decreasing ever since. In late January, levels dropped to where they were in early November. (Deaths remain high due to the significant delay between diagnosis and mortality, but are expected to start falling soon.) Even with the drop, however, daily cases are still well over three times what they were during the first peak of the pandemic in April and about double the levels seen during the summer peak in the USA.
The fall in the United States appears to be occurring before some of the most infectious variants of the coronavirus spread. But there is some reason for optimism, since even countries where these variants are common, such as the United Kingdom, are seeing a significant drop in cases. This suggests that at least part of the increase in cases was driven by socialization during the winter holidays, which many health experts feared would lead to an increase in cases.
But Dr. Tedros, from WHO, also suggested that social restrictions put in place in response to the increase in cases also played an important role. “It shows that this virus can be controlled, even with the new variants in circulation,” he said. “And it shows that if we continue with the same proven public health measures, we can prevent infections and save lives.”
Who needs health measures?
Tedros, however, also issued a note of caution, saying: “We’ve been here before. Last year, there were times in almost every country when cases dropped, governments opened doors very quickly and individuals let their guard down, just for the virus to roar again. “This caution is supported by several studies that indicated that states and countries that increased their restrictions too early saw continued infections and previous returns from generalized infections.
This is a basic result of viral spread. The drop in cases is the result of social restrictions, whether mandatory or voluntary, which reduce the rate of transmission of the virus to each infected individual. The ultimate goal of these restrictions is to reduce general cases so that when people start their daily activities again, there are very few infections, allowing contact tracking and isolation to limit the spread of the virus. Stop social restrictions too soon, and many more people will be infected, making contact tracking ineffective and starting new infections at a very high level.
This is what seems to have happened in the United States, which has never seen distinct waves of infections, but had a series of peaks standing out in a scenario of high levels of viral spread.
Unfortunately, the United States seems dedicated to revisiting its previous mistakes. At a time when infections were still well above any point before November, several states responded to the drop in new cases with plans to lift restrictions. Although California was a little cautious and only suspended hospitalization requests after ICU capacity increased last week, areas within the state are already allowing restaurants to reopen.
New York is taking a similar approach: restrictions have been lifted in much of the state and indoor dining will resume in less than two weeks. The Empire State is also planning to allow weddings of up to 150 people in March. These actions occur at a time when The New York Times reports that many key health workers stopped smoking during the pandemic due to conflicts with New York Governor Andrew Cuomo. In that article, Cuomo is quoted as saying that he does not trust his own experts.
About these new variants …
Relaxing restrictions so early is also a concern, because it is clear that the three most worrying variants are now circulating in the United States, although they do not yet appear to be widespread. These variants have the potential to outweigh some of the benefits of social restrictions or increase the speed at which the virus spreads in their absence.
To get a sense of the problems that the combination of new SARS-CoV-2 variants and completion restrictions can create, let’s take a look at the Brazilian city of Manaus. There, an initial wave of infections in May was extremely difficult, and blood donation studies indicated that up to 75% of the population was infected in October. A draft of the manuscript even suggested that the low infection rate that followed this wave was an indication that the region could have achieved collective immunity. As infections declined in late July, social restrictions were lifted. After months when infections remained low, entertainment venues were reopened in December.
And now the pandemic is back in Manaus, as described by a recent article in The Lancet. Local authorities have tried to impose social restrictions in response to the increase in new cases, but have backed down in response to strong public resistance. With the limits suspended, a second severe wave of infections hit the city.
In the new article, some of the researchers studying Manaus have four potential reasons. One is simply that previous studies overestimated the number of people who were exposed in the first wave. A second option is that we are seeing the impact of weakened immunity. Although several cases of reinfection have been reported, the number of second confirmed cases remains low and it is not clear whether this is due to limited testing or not.
Wear a mask
Related to this option is the possibility that some of the strains that now circulate in Manaus have contracted enough mutations to prevent the immune response generated by the first wave of infections. Finally, it is possible that some of these strains are simply more infectious and are doing better at reaching the population that went through the first wave without infection. Obviously, more than one of these four factors may be at play during the recent outbreak of infections.
Manaus is not a typical experience for other cities in Brazil, so that does not mean that the United States should expect to see an equivalent spike in infections, as these and other strains become more common here. But the possibility cannot be ruled out either, which is why limiting the spread of infections through the use of masks and social restrictions will remain critical, even with the peak of post-holiday cases disappearing.