One Year with COVID: Lessons Learned

Rachel Weinstein

Published: Mar 13, 2021

Sunday, March 14, 2021, marks the one-year anniversary of the first recorded COVID-19 death in Louisiana. Over the past year, almost half a million Louisianans have tested positive for COVID-19 and nearly 10,000 have died. Over the last 12 months, COVID-19 has killed more people in Louisiana than were killed by the flu, firearms, drugs, car accidents, and diabetes combined in 2019. The scale of this health crisis is unmatched in modern history.

Our scientific understanding of the novel coronavirus (or SARS-CoV-2) has advanced significantly since March of 2020. From months of strict Stay-At-Home Orders to the ability to open more businesses with the use of physical distancing and face masks, the more we learn about the virus, the more we are able to mitigate its spread while engaging in normal day-to-day activities. Increasing understanding of who is spreading COVID-19, how it spreads, and the settings where outbreaks are likely help us to adapt strategies for reducing its impact. Not only has the science of transmission evolved, but so has our understanding of the demographics of who has been most severely impacted. Data pertaining to the age, race, and sex of those who have contracted or died from COVID-19 have improved in quality and granularity over time.

While herd immunity through widespread vaccination represents a pathway to a sense of normalcy, quickly emerging variant strains threaten our progress. But this past year has provided us with the knowledge and tools needed to stay ahead of the curve. Here is a review of some major lessons learned during the previous 365 days with COVID-19.

Science of SARS-CoV-2

Built on a foundation of knowledge about coronaviruses dating back to 1940, our scientific knowledge about this new coronavirus has advanced significantly over the last year. Notably, researchers first became aware of the potential lethality of coronaviruses with the 2002 emergence of SARS. When the first Stay-At-Home Order was put into effect in Louisiana on March 22nd, 2020, residents were instructed to shelter in place, and to limit movement beyond essential needs. This period lasted nearly two months while the world gained valuable insights about the virus. SARS-CoV-2 seemed to be more contagious than many other coronaviruses, but exactly how it spread remained unclear.

Early research on COVID-19 published in March of 2020 concluded that the virus could be detected on cardboard for up to 24 hours. As a result, much focus was put on transmission from contaminated objects and surfaces. Within months, experts began to suspect that transmission through objects, also known as fomite transmission, occurred far less frequently than initially thought. Though we now know COVID-19 does not transmit very effectively on objects, it is still possible to be transmitted via a surface for one to two hours after an infected person has sneezed or coughed directly on it. For that reason, good hand washing practices are still highly recommended. Nonetheless, activities with some potential for fomite transmission, such as take-out and food delivery, are now understood to be relatively safe COVID-19 activities.

We now understand that most people contract COVID when they come in close contact with another person infected with the virus. COVID hitches a ride on respiratory droplets produced when an infected person speaks, sings, sneezes, coughs, or even just breaths. An individual becomes infected when those respiratory droplets are inhaled or absorbed by the mucus membranes in the nose or mouth. Over time, large respiratory droplets fall out of the air and the infectiousness of those droplets wanes.

Mounting evidence suggests that in poorly ventilated spaces, COVID can stay suspended in the air for over three hours. Case studies involving vertical apartment neighbors who share air ducts, and super-spreader choir practices are often cited. In the coming months, especially with more transmissible variants of the virus predicted to dominate U.S. cases, places like office buildings, schools, jails, grocery stores, and meat packing plants may have to increase measures to restrict spread. These places and other environments where people are exposed for long periods may need protections like respirators and better ventilation. Occupational Safety and Health Administration (OSHA) is working with the Centers for Disease Control and Prevention (CDC) to issue an emergency temporary standard for workplace ventilation this spring.

Accompanied by physical distancing, masks are incredibly cost-efficient and effective at preventing transmission. Masks reduce both the emission and inhalation of droplets by the wearer. It is estimated that 50 percent of transmissions occur from people who feel well and are not aware that they have a COVID-19 infection. In fact, we now know one significant way COVID-19 differs from other coronaviruses is in its ability to be transmitted by pre-symptomatic and asymptomatic carriers. This provides increased opportunity for undetected infectiousness — making the spread of the disease more difficult to contain. Infectiousness of pre-symptomatic and asymptomatic carriers amplifies the importance of universal mask wearing. In Louisiana, the second state-wide wave quickly receded after Governor John Bel Edwards issued a statewide mask mandate.

Confirmed cases of COVID-19 in Louisiana

 Download Data Source: The Data Center analysis of Louisiana Department of Health data.

Notes: Days with negative number of cases or deaths were removed from the chart. Negative numbers reflect a retroactive data dump of new information on one single day and distort daily trends.

Properly worn masks are highly effective at preventing spread of the coronavirus. In human experiments, multi-layer masks achieved blockage of respiratory droplets upwards of 80 percent. In light of the more transmissible new COVID variant strains, the CDC now recommends “double-masking”. Double-masking entails wearing a cloth mask over a medical procedure mask. Doing so improves the overall fit of the mask to the face and maximizes filtration properties. Double-masking has been found to reduce the wearers exposure to COVID by more than 90 percent.

Moreover, early evidence indicates that the amount of COVID-19 one is exposed to likely contributes to severity of illness and intensity of future transmission. In cases where people become infected while wearing a mask, there is an increased chance that the mask helped to reduce the severity of illness as well as the future likelihood of infecting others. And infections acquired from mildly symptomatic spreaders are less likely to be severe as well, though age and co-morbidities also play a significant role in the severity of illness a person experiences.

While the science behind masking is strong and continues to grow, this knowledge has not always translated to a change in behavior. A New York Times survey conducted during the first two weeks of July 2020 interviewed Americans about their mask wearing tendencies. Among parishes in Louisiana with over 50,000 residents, mid-summer coronavirus spikes in cases were linked to self-reported apathy towards mask wearing.

Mask wearing

Demographics of COVID-19

The evidence is clear; significant strides can be made in the fight against COVID with consistent and widespread masking and physical distancing. Understanding the source of outbreaks provides additional opportunities to prevent and reduce transmissions. Nationally, several studies have identified 20- to 49-year-olds as the primary source for sustained and resurgent COVID transmission. Local data of COVID cases by age group mirror national trends. Preceding the second and third waves, cases among 18- to 29-year-olds began increasing before all other age groups, and peaked higher. This pattern was followed closely by the 30- to 39-year-old age group.

COVID by age group weekly data

 Download Data Source: The Data Center analysis of Louisiana Department of Health data.

Note: Recent counts are likely to increase when additional reports are received. Week is based on sample collection date.

In August of 2020, the CDC identified a concerning increase in COVID cases among 18- to 22-year-olds. Young adults are less likely to adhere to some COVID-19 prevention measures, which researchers speculate may be contributing to this group’s infection rates. Notably, the number of new COVID-19 cases among White 18- to 22-year-olds increased 150 percent in the United States last summer but declined or stayed the same among young adults of racial and ethnic minority groups. Approximately 45 percent of all 18- to 22-year-olds attend college or university, and more than half identify as White. Institutions of higher education were strongly linked to growing cases among young adults in August of 2020. While colleges have been quick to address outbreaks on campus, these outbreaks contributed to significant COVID spread throughout the communities in which they are located.

Importantly, although young adults led infections in two of the U.S.’s major waves, the impact of these spikes did not break evenly across all communities. Nationally and locally, people of color have borne the brunt of the COVID-19 pandemic — including higher risk of exposure, severe illness, hospitalization and death. People of color have also borne the brunt of the economic fallout of COVID, as low-wage jobs with significant face-to-face interaction (restaurant servers, hotel desk clerks, and more) were disproportionately held by people of color when COVID hit. Notably, a Louisiana survey revealed people of all racial and ethnic minority groups were more likely to wear a mask than White people, consistent with national findings. This survey found that Black people were 20 percent more likely than White to wear a mask or cloth covering over their mouth and nose in public. Black respondents were also twice as likely as White respondents to indicate that they were “very concerned” about becoming infected with coronavirus and dying if infected. The disproportional health and economic impacts of COVID on low-income people and people of color are consistent with trends related to other disaster types. Disasters tend to increase inequity because more vulnerable individuals suffer more severe health impacts, greater income loss, and receive less government assistance despite experiencing equivalent or greater damages.

COVID in the workplace

Both nationally and locally, food processing workplaces have been hard hit by COVID-19. In Louisiana, food processing settings are responsible for the largest number of cases traced back to outbreaks in the state with 41 confirmed outbreaks leading to 1,059 confirmed cases. These workplaces are usually high-density, with many workers who live in congregate housing and share transportation, making them significantly high-risk for outbreaks. Mass testing studies from March to May of 2020 at selected meat and poultry facilities found widespread outbreaks that were comprised of largely pre-symptomatic or asymptomatic carriers. In Louisiana, butchers and other meat, poultry, and fish processing workers are disproportionally Hispanic and Black. Specifically, these food workers are 11 percent Hispanic and 47 percent Black, while Louisiana’s overall population is 5 percent Hispanic and 32 percent Black. The CDC confirms disproportional risk of COVID exposure at work contributes to the disproportionate illness and death among racial and ethnic minorities. Industrial settings such as factories and assembly plants face similar challenges and are the second leading venue for outbreaks in Louisiana.

Bars and restaurants are central to many COVID debates. Small businesses are less resilient in their ability to respond to disasters because of their vulnerability to the interruption of cash flow and limited access to capital during recovery. At the same time, infection control is uniquely challenging in restaurants and bars because of the need to remove masks while eating and drinking. One study published by the CDC found that people who had tested positive for COVID were twice as likely to have dined at a restaurant at some point in the 14 days prior to that positive test than individuals who had tested negative. The necessity for mask removal was central to the study’s findings.

In Louisiana, bars and restaurants have consistently been identified as top venues for COVID outbreaks. As of mid-February 2021, Louisiana Department of Health (LDH) contact tracers had identified 98 outbreaks responsible for 382 cases originating at restaurants and 50 outbreaks responsible for 537 infections from bars. Casinos, which have similar challenges with mask removal during food and beverage consumption and large gatherings in sometimes poorly ventilated spaces, also represent a leading venue for outbreaks in Louisiana. Many policy tweaks at the parish and state level have attempted to find a balance between safety and economic viability through restricting indoor seating capacity to improve physical distancing and limiting alcohol sales. However, physical distancing may not be enough at indoor venues. Case studies have linked infections acquired in restaurants to air conditioning flow. Without proper ventilation, transmission further than six feet away is a meaningful risk.

LA Outbreaks

Download Data Source: The Data Center analysis of Louisiana Department of Health data.

Note: Recent counts are likely to increase when additional reports are received. Week is based on sample collection date.

Nursing homes and other long-term care facilities are also highly conducive to outbreaks. In addition to living in a group home setting, residents are uniquely vulnerable to COVID-19 because of their age and co-morbidity status. Nationally, as of March 3rd, 2021, 22 percent of healthcare workers who died from COVID worked at a nursing home or other long-term care (LTC) facility. Deaths among these workers outpaced all healthcare occupational settings other than private hospitals. Nursing homes and other LTC facilities residents and staff were among the first to be prioritized for the COVID-19 vaccine. However, rollout has been slower than expected among staff. In late February, the CDC reported that among U.S. facilities with available data a median of 78 percent of LTC facility residents had been vaccinated but only 37 percent of staff members. The CDC has emphasized the need to overcome any barriers to access and increasing outreach to LTC staff given their high occupational risk.

Breakthrough vaccine development

To date, COVID-19 has killed more Americans than both World Wars combined. Our united efforts to slow the spread of the virus, and scientists’ accelerated efforts to create safe and effective vaccines represent humanity’s extraordinary ability to come together and overcome a common foe. Notably, wartimes have often been the catalyst for some of the greatest innovations in history. Among the 28 vaccines developed during the 20th century, more than half of them were developed and advanced during the 1940s as a direct result of World War II. We continue to benefit from many wartime medical advancements including: widespread use of anesthesia during the Civil War, mass production of penicillin during War World II, and treatment of burn wounds during the Vietnam War. Historically, war-like events and other existential threats have sparked national – and sometimes even global – unity and urgency, which in turn have catalyzed unprecedented levels of financial support, innovation, and collaboration between governments, business leaders, and scientists.

The development of COVID-19 vaccines has been propelled by substantial government investment. Moreover, vaccines from Pfizer and Moderna benefitted from important scientific discoveries about messenger RNA (mRNA). For decades, researchers have been studying the potential of mRNA in a range of contexts. Messenger RNA vaccines are under development to treat cancer, and have reached the clinical trial stage for preventing HIV infections. With significant public and industry support, this technology was quickly adapted to create safe and effective COVID-19 vaccines.

Both the Pfizer and Moderna vaccine proved to be nearly 95 percent effective at preventing symptomatic infection during clinical trials when tested against the original variant of SARS-CoV-2. While the later-released single dose Johnson & Johnson vaccine had slightly lower efficacy results, comparing it to the others is difficult because more variant strains were circulating by the time the J&J vaccine was tested. Pfizer and Moderna have already shown somewhat decreased efficacy when tested against new variant strains. Importantly, all vaccines available to the public have been 100 percent effective at preventing death. That means, getting vaccinated may very well save your life, and may reduce the impact of contracting COVID to something more akin to a common cold.

Strong headway has been made in vaccine research, development, and distribution. While the vaccine offers much desired hope for the future, the emergence of mutant strains represents new obstacles in our fight against the virus.

How COVID-19 mutates

When a virus enters a host cell, it begins to replicate, and the new virus particles go on to infect other cells. Replication of genetic material is not a perfect process and mistakes or mutations can result. Often times, those mistakes are inconsequential and resulting variant strains do not survive. But occasionally, a mistake in the replication process results in a characteristic that “improves” that variant strain in some way and passes on to other people.

There are a number of ways mutations can change the behavior of COVID-19. Mutations may result in new variant strains of COVID-19 that are more easily transmitted, cause more mild or severe disease, become undetectable by current COVID tests, are less effectively treated by current therapies and/or escape natural or inoculated immunity. Escaping such immunities means that those who have already had COVID-19 or been vaccinated may still become infected and spread new variants of the virus to others.

At the start of the COVID pandemic, scientists were comforted by the apparent slowness of emerging mutations. However, within the last few months several concerning mutations have been identified. The emergence of variant strains B.1.1.7 in the UK, B.1.351 in South Africa, and P.1 in Brazil set off alarm bells. Initial studies suggest these new strains are less efficiently treated by currently approved therapies, and partially escape natural and inoculated immunities. B.1.526, a variant strain in New York City represented 3 percent of cases in January 2021 but by mid-February, it was detected in 12.4 percent of cases. While the exact nature of this New York City variant is not yet fully understood, it shares similar characteristics to the South African and Brazilian strains which are less responsive to treatment and partially escape vaccine and natural immunity.

Importantly, the virus mutates faster the more people it infects. Thus, reducing transmission between non-vaccinated folks will significantly stave off COVID’s ability to evolve. In other words, to defeat the virus, it is more important than ever to continue to wear a mask, social distance, avoid crowded places, and get a vaccine when it is your turn.


The lessons learned over the last year are not likely to become obsolete anytime soon. Scientists now have a deeper understanding of the mechanisms of COVID transmission, and this understanding will be highly beneficial as evolving strains emerge.

Masks have proven to be highly effective at saving lives and will continue to be relevant until COVID is more fully controlled. Also, workplace ventilation standards may become essential for reducing transmission of COVID (and other viruses). As large numbers of Americans get vaccinated, clear and frequently updated guidance from the CDC about the safety of various behaviors and settings will be essential to combatting the virus. And Americans’ willingness to adhere to this guidance will be key to our success in the fight against COVID.

The COVID pandemic has demonstrated how interconnected we all are. Virtually every American has been impacted by the disease itself, the restrictions imposed in order to reduce the pandemic’s death toll, or both. But our joint efforts to reduce the spread of the virus, and the rapid development of multiple vaccines are testaments to our ability to come together and fight a common foe. And light is at the end of the tunnel. The CDC has issued new guidance that adults who have been fully vaccinated are now clear to gather indoors together without a mask, allowing even high-risk individuals who are vaccinated to embrace loved ones from different households for the first time in a year. Eventually, full reopening of our favorite establishments, celebrating Mardi Gras, and enjoying festival season can happen, but only if enough people “join the herd.”

Special thanks to Sara Scates, MS and Alicia Majeau, MS for their review of this paper.


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