Five years ago, a group of individuals in Wuhan, China, fell ill due to a previously unidentified virus. The pathogen lacked a name and the condition it created was not yet recognized. Subsequently, this virus initiated a pandemic that revealed significant disparities in global health systems and transformed public perspectives on managing lethal emerging pathogens.
Although the virus remains in circulation, humanity has developed immunity largely through vaccinations and previous infections. Its severity has decreased compared to its early days in the pandemic, and it no longer ranks as the leading cause of mortality. Nonetheless, the virus continues to evolve, necessitating ongoing surveillance by scientists.
The origins of the SARS-CoV-2 virus are still not definitively known. Scientists posit that it likely circulated in bats, akin to numerous coronaviruses. It is believed that the virus then jumped to another species, including racoon dogs, civet cats, or bamboo rats, which subsequently transmitted it to humans who handled or processed these animals at a market in Wuhan, where the first human cases were identified in late November 2019.
This method of transmission is well-documented and resembles the pathways that caused the earlier SARS epidemic. However, this theory remains unproven for the virus responsible for COVID-19. The presence of various research laboratories in Wuhan dedicated to studying coronaviruses has intensified debates over the possibility that the virus may have leaked from one of them.
Unraveling the true origins of the pandemic is an intricate scientific challenge, one further complicated by political tensions surrounding the virus’s origins. International researchers have voiced concerns regarding perceived efforts by China to withhold critical evidence. It may take years, if not longer, to ascertain the exact origin of the pandemic.
The death toll from COVID-19 is likely over 20 million. While the World Health Organization reported that member nations documented over 7 million deaths attributed to COVID-19, experts estimate that the actual number could be at least three times higher. In the United States, recent data from the Centers for Disease Control and Prevention indicates an average of around 900 weekly deaths linked to COVID-19 over the past year.
Older adults continue to be disproportionately affected by the virus. According to the CDC, individuals aged 75 and older represented approximately half of all COVID-19 hospitalizations and deaths in the U.S. last winter. WHO Director Tedros Adhanom Ghebreyesus emphasized that, “We cannot talk about COVID in the past, since it’s still with us.”
In terms of vaccines, scientists and manufacturers achieved remarkable speed in developing COVID-19 vaccines, which have saved millions of lives globally and played a crucial role in restoring normalcy. Less than a year after the virus was identified, health authorities in the U.S. and UK approved vaccines from Pfizer and Moderna. Prior research laid the groundwork for the creation of mRNA vaccines, which included notable discoveries that earned a Nobel Prize.
Alongside the mRNA vaccines, there is also a more traditional option from Novavax, with some countries exploring other alternatives. Although distribution to poorer regions was initially sluggish, the WHO estimates that over 13 billion COVID-19 vaccine doses have been administered worldwide since 2021.
While these vaccines have proven effective in preventing severe illness, hospitalization, and death, they are not foolproof. Mild infection protection tends to diminish after several months. Much like flu vaccinations, COVID-19 shots require regular updates to keep pace with the virus’s evolution, contributing to public dissatisfaction at the necessity for repeated vaccinations. Researchers are also working on next-generation vaccines, such as nasal versions that may enhance infection blockage.
In terms of dominant variants, genetic mutations occur as viruses replicate. This virus has exhibited similar behavior. Variants have been named using Greek letters, including alpha, beta, gamma, delta, and omicron. Delta emerged as the dominant strain in the U.S. by June 2021, raising significant alarm due to its increased hospitalization risk compared to earlier strains.
However, a new variant, omicron, surfaced in late November 2021 and spread rapidly. Dr. Wesley Long, a pathologist from Houston Methodist in Texas, noted, “It drove a huge spike in cases compared to anything we had seen previously.” Despite its rapid spread, the WHO reported that omicron generally caused milder symptoms than delta, potentially due to growing immunity from vaccinations and prior infections.
Currently, the omicron subvariant called XEC is prevalent in the U.S., comprising 45% of circulating variants in the weeks leading up to December 21, according to the CDC. Long reassured that existing COVID-19 treatments and the newest vaccine boosters should continue to be effective against it since “it’s really sort of a remixing of variants already circulating.”
Long COVID remains a challenge for millions, manifesting as a sometimes debilitating condition that lingers long after initial infection. Recovery from COVID-19 can take several weeks, with some experiencing chronic issues that last three months or more, including fatigue, brain fog, pain, and heart problems. The specific reasons why only some individuals develop long COVID, even after mild cases, remain unclear, although vaccination has shown to reduce its risk.
The underlying causes of long COVID are yet to be fully understood, complicating the search for effective treatments. Researchers have increasingly identified remnants of the coronavirus lingering in certain individuals’ bodies long after their initial illness; however, this does not account for all cases.
