It is easy to get swamped by all the research on coronavirus. New Zealand’s Science Media Centre is keeping track of much of it so you don’t have to. The Research Tracker is prepared by Dr Robert Hickson for the Science Media Centre New Zealand.

Non-vaccine-related papers

Indoor transmission can occur beyond 2 metres

A review of 13 studies concludes that there is good evidence for SARS-CoV-2 transmission beyond 2 m indoors. Studies from a range of indoor settings were included. The frequency of such events is uncertain, and several factors are associated with long distance transmission.

For example, insufficient air replacement and singing can increase the concentration of airborne viral particles, while recirculating unfiltered air can distribute these particles. The paper has not yet been peer reviewed.

Infection risks for different essential workers

An Arizona study found that first responders are at a greater risk of infection than healthcare workers who directly interacted with patients. First responders included correctional officers, fire fighters, law enforcement, and emergency medical services workers.  

The incidence of SARS-CoV-2 infection (per 1000-person weeks) was 60% higher for first responders than healthcare workers when confounding factors were excluded. The incidence among other essential personnel (such as education, childcare, social services, and retail workers) was similar to healthcare workers. There were higher risks for education, childcare and social service workers than others in their group.

The study started before some interventions, such as school closures, reduced risks for some occupations. The paper was published in JAMA Health Forum.

Statin treatment can increase the risk of developing severe Covid-19

Hospitalised Covid-19 patients given statins when admitted had an 18% higher risk of developing more severe symptoms. Mortality was not affected by statin treatment. This study, involving over 4,000 patients, came to different conclusions about the effect of statins than earlier smaller studies. The authors suggest that statins may increase inflammatory responses. The paper was published in PLOS ONE.

Long Covid

Long Covid symptoms occur in both adolescents and adults, according to a large German study. Incidence (out to 3 months post-infection) was greater in adults, but the results suggest increased post-Covid pressures on medical services will apply for all age groups. The paper has not yet been peer reviewed.

Wastewater testing can help detect new mutations earlier

Wastewater testing can provide a good early warning of new variants or mutations, according to a study from Pune, India, identified. Mutations were found in wastewater samples that were not detected in infected people, or did not appear in clinical samples until a month or more later. The paper was published in Science of the Total Environment.

Genetic factors that influence Covid severity

Patterns of transcription for several human genes were associated with more severe Covid-19 in people under 50. Machine learning was used to analyse the data. Five genes were found to be potentially important drivers of development of severe Covid, based on their differences in transcription levels between severe and less severe cases.

In lab experiments one of these genes was found to strongly affect uptake and replication of the virus. Inhibiting it reduced entry into and replication in a lung cell like. The authors suggest that this gene could be a potential therapeutic target.  The paper was published in Science Translational Medicine.

Open schools + mitigation practices don’t appear to increase infection rates

A US study found that opening schools for in-person learning did not often lead to increased community infection rates. However, this did not hold for some regions in southern states. In these states mitigation measures tended to be more limited, but other factors may also have contributed to the variability between regions and this requires further study. The research was conducted before the Delta variant became prevalent. The paper was published in Nature Medicine.

In Japan schools did not appear to have a significant impact on community spread. The study compared infection rates in communities where schools were closed with similar communities that kept schools open. There were no significant differences in community infection rates between these two groupings. In Japan, schools that allowed in person learning generally had stringent mitigation practices. The paper was published in Nature Medicine.

Possible seasonal influence on infections

An analysis found that there is a seasonal pattern to Covid-19, similar to the 'flu and colds. Outbreaks in summer months were less frequent, and attributed to other factors, such as air-conditioning and social clustering at outdoor events. The authors acknowledge that the newness of Covid-19 means that a different pattern may emerge as more data on infections is collected. The paper was published in Nature Computational Science.

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