SARS-CoV-2 and Influenza Multiplex Testing

SARS-CoV-2 and Influenza A/B, the predominant types of flu to spread each year with its peak around December to February, are both spread via respiratory droplets. The dynamics of how a co-infection by the two viral pathogens could influence the disease course in people  is unclear.  A report published in Science explains that the flu season in the Southern Hemisphere, which typically occurs in March, was unprecedented this year with only a few cases, compared to hundreds of cases during the same  period in previous years. This sharp decline could be attributed to the additional public health measures, such as travel restrictions, mask wearing, school closures, and social distancing, that were in place in response to COVID-19 in March 2020. As a result, co-infection was rare and has not been fully analyzed up to now. Understanding the possible interactions between COVID-19 and other infections requires a large number of patient samples to be tested for SARS-CoV-2 and other respiratory viruses. Symptoms for both flu and COVID-19 are largely similar but require different treatment protocols. 

Thus, as flu season approaches in the United States and around the world,  and as schools, universities and businesses  reopen, the need for rapid, dual diagnostic tests is more critical than ever  for both research and treatment purposes. 

There are currently four multiplex assays which have FDA emergency use authorization and are summarized in the table below. All of the tests can both differentiate and detect nucleic acids from SARS-CoV-2,  Influenza A, and Influenza B. The Qiagen and Biofire test can also detect 22 other viral and bacterial pathogens, including Rhinovirus, Respiratory Syncytial Virus (RSV) , and Adenovirus. Labcorp is also currently working on developing an at-home test for COVID-19 and Influenza A/B which could help increase accessibility of multiplex tests. 

In addition, the importance of widespread vaccination for flu this season is more critical than ever before, especially since the dynamics of the spread of SARS-CoV-2 and Influenza is unclear and there is a  potential that high number of patients with co-infections could  overburden hospitals and as we have seen in earlier part of the pandemic, could lead to a bottleneck in critical medical resources, such as ventilators.

Data collected by the CDC shows that only 45% of adults in the United States received the flu vaccine for the 2018-2019 flu cycle. In order for vaccinations to be most effective in curbing the spread of the disease, at least 80% of the population will need to receive the vaccine.