As we enter our fourth year of living with Covid-19, our fervent hope is that Covid-19 may become like many other cold-causing coronaviruses. While this would be a far better outcome than years past, it is by no means the end of our troubles with this virus. Cold-causing coronaviruses return annually to infect thousands, if not millions, of people, leading to sometimes severe respiratory issues and even death.
Earlier in the pandemic, we discussed the similarities between SARS-CoV-2’s continual waves of reemergence via variants and the seasonality of cold-causing coronaviruses. A study from 2017 showed the pattern of emergence of a wide range of coronaviruses, which could be extrapolated to SARS-CoV-2.
In fact, some human cold-causing coronaviruses are lethal. Two viruses, OC43 and NL63, regularly impact at-risk communities, such as nursing homes. Here we will describe these viruses in greater detail, lending credence to the threat of cold-causing coronaviruses.
Researchers Patrick et al. from the University of British Columbia Centre for Disease Control characterized an outbreak of respiratory illness due to HCoV-OV43 in 2003. From July 1 to August 22, 2003, 95 of 142 residents (67%) and 53 of 160 staff members (33%) were infected and experienced symptoms. None of the 53 staff members were hospitalized or died, but this was not the case for the residents.
With a median age of 83.7 years, this elderly facility and many like it are ripe for attack by dangerous pathogens. Close-quarters contact between residents and at-risk immune systems allows viruses to move swiftly from host to host.
The most common symptoms are cough (66.3%), runny nose (66.3%), sore throat (24.2%), and fever (21.1%). Not typically associated with a cold, however, is the 12 cases of pneumonia (12.6%), eight hospitalizations (8.4%), and subsequently, eight deaths (8.4%).
In a more recent study, researchers Hand et al. follow an outbreak of human coronavirus NL63 in an elderly facility in November 2017. Between November 1st and 18th, 20 residents displayed cold-like symptoms, with a median age of 82.
All patients had concurrent conditions leaving them at risk for severe disease, including heart disease (70%), dementia (65%), and hypertension (40%), among others.
As with OC43, patients displayed common cold-like symptoms, including coughing, congestion, and fever. However, more concerningly, a higher proportion of patients developed pneumonia (70%). Six of twenty were hospitalized, though no deaths were recorded.
These cases echo the fact that cold-causing coronaviruses will not be a major problem for many people, particularly those with healthy immune systems. However, some estimates suggest the at-risk population for severe illness is roughly four of ten adults. The elderly, the immunocompromised, and children are among the biggest targets for cold-causing coronaviruses to wreak the most havoc.
Coronaviruses has always been a killer. Covid-19 being relegated to a seasonal cold virus does not mean it will not be lethal. It is time we paid more attention to cold-causing coronaviruses and did our best to eliminate the whole family, either with broadly neutralizing antibodies or with a whole new pharmacopeia of safe and effective medication. The search for broadly active vaccines and truly effective drugs to prevent and treat coronavirus infections is urgent.