COVID-19, the disease caused by the novel coronavirus, has been raging across the world for more than two years, infecting over 99 million people and killing over 1 million in the United States alone. While some experts hoped that the virus would follow a seasonal pattern and decline during the warmer months, the reality has been more complex and unpredictable.
Spring 2020: The first wave hits the Northeast
The first confirmed case of COVID-19 in the United States was recorded in January 2020 in Washington state, but it was the Northeast that bore the brunt of the disease that spring. New York, New Jersey, Connecticut, Massachusetts and Rhode Island recorded the highest per-capita cases and deaths among all states between March and May 2020. Health care facilities in the region were overwhelmed, dealing with shortages of tests, personal protective equipment, ventilators, beds and even space for the dead. “It was hell,” said Dr. Brian Strom, chancellor of Rutgers biomedical and health sciences in New Jersey.
As the virus spread across the country and the world, the World Health Organization declared the outbreak a pandemic on March 11, 2020. Many state officials enacted drastic measures to curb the transmission of the virus, such as stay-at-home orders, school closures and business restrictions. California issued the first stay-at-home order on March 19, 2020, and within a week, 21 more states followed suit. These measures had a significant impact on the economy, sending unemployment skyrocketing to unprecedented levels.
Summer 2020: A respite or a resurgence?
Some experts anticipated that COVID-19 would favor winter like its cousins, such as the common cold and influenza, and fade during the summer months. However, the exact relationship between temperature, humidity and sunlight and the virus’s survival and transmission was unclear and likely influenced by other factors, such as human behavior and immunity. Some parts of the Southern Hemisphere, such as Brazil and South Africa, saw wintertime increases in confirmed cases in June and July 2020.
In the United States, some states that had avoided major outbreaks in the spring experienced surges in cases during the summer, especially in the South and West. Arizona, Florida, Texas and California were among the hardest-hit states in June and July 2020. Some of these states had reopened their economies earlier than others or had less strict public health measures in place. Dr. Brad Spellberg, the chief medical officer at the Los Angeles County-University of Southern California Medical Center, said that he believes that California’s stay-at-home order in March helped stave off a spring outbreak in the state, but that relaxing it too soon led to a summer surge.
Fall 2020: A second wave sweeps across the country
As autumn arrived in 2020, many states experienced a second wave of COVID-19 cases that surpassed their previous peaks. The Midwest and Mountain West regions were particularly affected, with states like North Dakota, South Dakota, Wisconsin and Montana reporting record-high numbers of infections and hospitalizations. Some of these states had low population density and few urban centers, which may have delayed their exposure to the virus but also made them more vulnerable to outbreaks once they occurred.
The fall surge coincided with several factors that may have contributed to increased transmission of the virus, such as colder weather that drove people indoors where ventilation was poor; increased travel and gatherings for holidays such as Halloween, Thanksgiving and Christmas; pandemic fatigue that led to reduced compliance with public health guidelines; and lower levels of immunity in some populations due to limited exposure to the virus earlier in the year.
Winter 2020-2021: A third wave hits a new record
The winter of 2020-2021 marked the deadliest period of the pandemic so far in
the United States. More than 3,000 people per day died due to COVID-19 on average in January 2021. The country reached a grim milestone of over 400,000 deaths on January 19, 2021. The virus spread rapidly across all regions of
the country, with no state spared from its devastating impact.
The winter wave was fueled by several factors that compounded each other,
such as continued holiday travel and gatherings; increased circulation of new
and more contagious variants of the virus, such as the B.1.1.7 strain first
detected in the United Kingdom; limited availability and distribution of
vaccines; and overwhelmed health care systems that struggled to cope with the
influx of patients.
Spring 2021 and beyond: A hopeful outlook or a cautious warning?
As spring 2021 approached, there were some signs of hope that the pandemic
was finally slowing down in the United States. The number of new cases, deaths
and hospitalizations declined significantly from their winter peaks, reaching
their lowest levels since October 2020 by late February 2021. The rollout
of vaccines accelerated, with more than 100 million doses administered by
March 12, 2021. Several states eased or lifted their restrictions on
businesses, schools and social activities, citing the improved situation and
the economic recovery.
However, some experts warned that the pandemic was far from over and that
relaxing the public health measures too soon could lead to another surge in
cases, especially as new variants of the virus continued to emerge and spread.
They urged people to remain vigilant and follow the guidelines of wearing
masks, social distancing, avoiding crowds and getting vaccinated when eligible.
COVID-19 has proven to be a pandemic unbound by seasons, affecting different
regions of the world at different times and in different ways. While the virus
may have some seasonal patterns, they are not consistent or predictable enough
to rely on as a strategy to control its spread. The best way to end the pandemic is to use all the tools available to prevent infections, treat illnesses and protect populations.