Covid-19 could struggle to compete with seasonal coronaviruses, study suggests

Covid-19 may find itself in competition with seasonal coronaviruses and either struggle to persist in the long-term or push out one or more existing ones, new research suggests.

A study led by the MRC University of Glasgow Centre for Virus Research carried out what is thought to be one of the most detailed studies of coronaviruses in a patient population.

Experts said it could be important for understanding and predicting the behaviour of Covid-19.

When data on age and seasonal risk profiles are lacking, particularly early on in an outbreak, we can learn from other infectious diseases that spread in a similar way

Some coronavirus infections are a common cause of mild colds, infecting thousands of people every year in the UK and mostly circulate in the winter in temperate regions, where they are often referred to as seasonal coronaviruses.

Researchers used data from more than 70,000 NHS Greater Glasgow and Clyde patients with respiratory illnesses attending GP surgeries and hospitals between 2005 and 2017, who were tested for a panel of respiratory viruses, including common seasonal coronaviruses, to look for patterns related to age and seasonal frequency and any variation between the different coronavirus types.

They found different types of coronaviruses coexist in most winter seasons in the UK and exhibit structured seasonal patterns, with some appearing to generate illnesses in the community at the same time. But others appeared to circulate in their own unique pattern.

Researchers said the findings could suggest SARS-CoV-2, the coronavirus causing Covid-19, may find itself in competition with current seasonal coronaviruses and either struggle to persist in the long-term or may push out one or more of the existing seasonal coronaviruses.

Lead author Dr Sema Nickbakhsh, said: “When data on age and seasonal risk profiles are lacking, particularly early on in an outbreak, we can learn from other infectious diseases that spread in a similar way.

“So by looking at the robust data we have on other coronaviruses from Scottish patients from 2005 to 2017, we can improve our understanding of normally-occurring seasonal coronaviruses, which is greatly needed to guide future Covid-19 science and to prepare for the post-pandemic era.”

Dr Nickbakhsh added: “More research is needed to understand whether infection with seasonal coronaviruses in young children provides lasting immunity and whether seasonal coronaviruses can also protect against SARS-CoV-2. ”

The World Health Organisation says the virus can be transmitted in all areas “including areas with hot and humid weather” and there is currently no suggestion Covid-19 transmission will slow due to sunny weather.

Researchers in Glasgow said so far Covid-19 appears to be more similar to flu than seasonal coronaviruses in terms of the fraction of cases leading to severe illness and their older age profile, although this comparison is currently complicated by data biases.

They said detailed information on seasonal coronaviruses will be important for predicting what will happen to Covid-19 in the long term, and its impact on other respiratory viruses.

The researchers also found common seasonal coronaviruses are detected among all ages, which differs from Covid-19, where cases in children have rarely been reported.

It is unclear whether children are less susceptible to infection with SARS-CoV-2 virus or whether they are susceptible and spread infection but are protected from severe illness.

The research is published in the Journal of Infectious Diseases.