Who Knows Why COVID Cases Are Dropping Dramatically?

Have you been paying attention to the latest coronavirus updates? There’s good news! COVID cases are dropping! Do the experts know why?

It’s a mystery! We’ve been told that winter is the worst time of year for coronavirus transmission. That’s because the weather is awful. People are closer together indoors and are breathing dry, heated air. And let’s not forget the variants. They have been spreading like crazy. So how come COVID cases are dropping in so many places so suddenly?

The Confusing Data:

Several weeks ago the Coronavirus Resource Center at Johns Hopkins revealed scary spikes in cases. In January the United Kingdom was a mess. Variant B.1.1.7 was proliferating out of control. Daily cases hit nearly 70,000.

Germany had a double spike in December and January. Italy had a nasty resurgence around the end of November and then another bump up in January. Colombia peaked in January too and then started a sharp decline.

Look no further than the US, though. According to the New York Times Map and Case Count, we hit a peak of more than 300,000 daily cases on Jan. 8, 2021.

As of February 17, 2021, the daily total was 70,176. The seven-day average was 77, 665, down from 259,571.

As of February 18, 2021, the 14-day change in the US was -43%. Hospitalizations were down 30% and deaths were lower over the last two weeks by 34%.

Drilling Down By States:

COVID cases are dropping in 44 states!

Remember when North Dakota was in terrible shape? Wisconsin, Wyoming, and Minnesota were also in trouble. They are all doing much better now.

COVID cases are also dropping in California, which had a double surge not that long ago. A couple of weeks ago, there was a huge strain on ICU staff in southern California. Things are better now. Arizona, Arkansas, Illinois, Iowa, Nevada, New Mexico, and Washington are also reporting that COVID cases are dropping.

What’s Going On?

Once Americans got past the holiday travel season and the resulting surge, new infections started declining. Hospitalizations and deaths are also heading downward.

Scientists are not entirely certain what accounts for the dramatic reduction. One possibility is that there has been a huge change in close person-to-person interactions. Perhaps people have taken to heart the advice of public health authorities to wear masks, stay far apart and scrub hands religiously.

Another possibility is that the vaccination program is working faster than anyone imagined possible. There is also the possibility that many more people than realized have acquired immunity because of widespread infection with SARS-CoV-2.


Does any of that make sense? Maybe. But I am having a hard time putting all the pieces together into a coherent puzzle. For one thing, the weather has been even worse than usual. That means a lot of togetherness indoors. If anything, cases should be rising throughout February rather than declining.

Then there are the variants. The authorities have been telling us that the UK variant B.1.1.7 is way more contagious than the old strains we have been dealing with. And we have been told B.1.1.7 is spreading fast in the US.

I am challenged by these contradictions. Yes, the UK had a horrific spike in January. At its peak, the country was dealing with nearly 60,000 daily cases. Hospitals were overwhelmed. But even with the variant, cases have dropped precipitously in recent weeks. At last count, there were about 11,500 confirmed cases each day.

The Baffling Data from India:

Worldwide, coronavirus cases are dropping by about 16 percent. India is experiencing even more impressive reductions. In September, the country was reporting nearly 100,000 new cases daily. Now the number of COVID cases is dropping significantly to about 11,000 cases. Hospitalizations are also down.

The country has only recently begun to get its vaccinations underway, so it is unlikely that the reduction can be attributed solely to the vaccine program.

Some experts suggest that the country could be nearing herd immunity. That seems unlikely, though, because the seropositivity rate is roughly 20%, well short of the 70% to 85% required to accomplish such protection.

Others attribute the decline to mask-wearing, which has been mandated by the Indian government. In some cities the fines for not wearing a mask are substantial. And yet many people in India live in close quarters and they are not all wearing masks.

One other argument for why COVID cases are dropping so fast is that people in India have strong immune systems. Some public health authorities have suggested that people are exposed to so many serious infections such as tuberculosis, cholera, and typhoid that they are more resistant to SARS-CoV-2.

I am not buying it. India was hit very hard by the pandemic. It has the highest number of COVID cases after the US and is just ahead of Brazil. Why would cases start plummeting over the last couple of months?

No Easy Answers!

I do not have a clue to why there has been a worldwide decline in COVID cases. And there are lots of exceptions. Brazil is still a mess. France and Iran have seen improvements from their peaks, but cases are going up again. Peru and Poland are experiencing upticks after declines. And Sweden is not improving the way its Nordic neighbors have.

Whatever the reason COVID cases are dropping, public health authorities in India warn that “danger still lurks around the corner.” Variants of the virus could trigger another wave of infection.

The New England Journal of Medicine (Feb. 17, 2021) reported that the Moderna and Pfizer vaccines are quite effective against the UK variant B.1.1.7 but not as good at neutralizing the South African variant.  Variants do not stay put. The South African form of COVID-19 is already circulating in the US.

Final Words:

As far as we can tell, no public health expert can explain exactly why COVID cases are dropping. We have no way of telling whether the trend will last.

Given the uncertainty, it makes sense to continue to follow the CDC guidelines and get vaccinated. The sooner people are protected from this virus, the better. Let’s hope that the worst is behind us and that there is lasting light at the end of this horrific tunnel.

Follow Up!

We have received a large number of comments to this post from people who maintain that the reason the number of COVID cases is dropping dramatically relates to changing PCR test procedures. Many people insist that the tests have been unreliable. They are certain that there are far fewer cases in the US and around the world because of false-positive test results. Lower case counts, they say, are due to new guidelines.

Then there are other people who are convinced that there are way more people who have been infected with SARS-CoV-2 but have not been tested. The bottom line seems to be that there is tremendous mistrust about both testing and reporting of cases.

Let’s ignore cases for a moment. There are two other metrics that are independent of case counts. Hospitalizations and deaths are quantitative measurements that confirm something is changing. Over the last two weeks, hospitalizations in the US are down 30%. Deaths in the US have declined 34% over the same period of time. Globally, COVID deaths are also down.

These are what public health authorities call “lagging indicators.” That is to say, they follow by a week or two the total number of cases. In the past, when case reports surge, hospitalizations and deaths follow over the next few weeks. If hospitalizations and deaths continue to trend downward, we will be more confident this is real. Of course, we will be following the data so we can keep you informed about what is happening.

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