Is there a correlation between the end of mask mandates and the rise in cases of the common cold and influenza?

The start of the summer is aligning with another new beginning, one in which many around the world make a return to the “New Normal” and relearn what life was like before COVID-19. While some take baby steps in adjusting to a post-pandemic landscape, most are ready to step into their typical routines that they once knew.

A major change has erupted across the United States in the past couple months in terms of leaving COVID-19 in the past: unmasking. The U.S. Centers for Disease Control and Prevention stated on May 13, 2021, that those who are fully vaccinated—meaning they have received the single dose of the Johnson & Johnson vaccine or both doses of the Pfizer/Moderna vaccines, and have had these vaccines in their systems for two weeks—may go maskless in the majority of public settings. As states and local governments across the country have come to terms with this new advisory, more people have felt comfortable following the guidelines and discarding their face coverings from over the past year. However, with that shift, common ailments are making a comeback in a peculiar fashion.

The difference between seasonal influenza and COVID-19

According to the CDC, “influenza (flu) and COVID-19 are both contagious respiratory illnesses, but they are caused by different viruses.”1Despite the similarities of each illness, there are distinct qualities about the two diseases. Both viruses lead to several critical symptoms including coughing, fever, fatigue, shortness of breath and muscle aches. The two types of viral infections vary in the timing of when these symptoms typically occur. With the flu, patients will begin to experience symptoms around one to four days post-exposure; whereas with COVID-19, patients experience symptoms anywhere from two to 14 days post-exposure. Another major difference between the two diseases is in their recovery states. While most people who come down with the flu will recover within a few days with medications and rest, COVID-19 recovery can last anywhere from weeks to months. The CDC also states that even though both viruses spread in the environment in a similar fashion, COVID-19 is more contagious than influenza.

Understanding how a virus, like influenza or SARS-CoV-2, spreads is important in determining its rate of infection. Scientific experts rely on the basic reproduction number, R0 or R-naught, to determine the average amount of people that can be infected by an individual who carries the virus.2The R0 is calculated using the average of three factors: the infectious period of the disease, the way of transmission and the amount of people who have been in contact with an infected subject.

According to an article published by the University of Michigan School of Public Health, the R0 range of seasonal influenza sits at 0.9 to 2.1.3The data also shows SARS-CoV-2, the virus that causes COVID-19, has an R0 range of 1.5 to 3.5, which demonstrates how much more it can reproduce as opposed to the flu. While scientists are working on determining the R0 for the Delta variant of COVID-19, a table produced by Imperial College London estimates the range being anywhere in between 5-84, with the CDC saying the strain is as contagious as chickenpox.

How the seasonal flu declined during the time of COVID-19

Throughout the pandemic in 2020, COVID-19 took center stage and the typical flu season received little to no attention. This is not necessarily a coincidence though; the incidence of seasonal influenza was not as common as in years past. According to data from the CDC’s website, there was only one influenza-related pediatric death reported in the 2020-2021 flu season. Meanwhile, the previous flu season in 2019-2020 resulted in 199 deaths.5On that same wavelength, Scientific American reported there were approximately 600 deaths from influenza in the U.S. during the 2020-2021 season.6This number is small compared to the 22,000 deaths in the 2019-2020 season and the 34,000-recorded deaths in the 2018-2019 season.

The novel Coronavirus took precedent in the headlines during the regular flu season in 2020-2021 due to its substantial amount of deaths in the U.S. and worldwide. According to data published by the Center for Systems Science and Engineering at Johns Hopkins University, there have been more than 3.8 million deaths related to COVID-19 globally, with more than 600,000 of those in the U.S. alone (as of June 23, 2021).5

What does the most recent flu season mean for the upcoming season

Public Health officials have noted the decrease in seasonal influenza cases throughout the span of the COVID-19 pandemic, and several are raising concern about the negative effects of the non-existent flu season last year. The CDC reported that the hospitalization rate for seasonal flu during the 2020-2021 season was 0.7 per every 100,000 people in the U.S.7 This marked the lowest number of cases on record.

Advisory Board spoke with Rachel Baker, who studies public health and infectious disease at Princeton University for its High Meadows Environmental Institute, to see what her research has found in correlation to the low flu numbers. She and her team attributed the increase in social distancing to prevent the spread of COVID to the 20% decrease in respiratory syncytial virus (RSV) in the U.S.8

In an article published by CNN, Lynette Brammer, the head of the CDC’s Domestic Influenza Surveillance Team, predicted an uptick in flu cases as the general population returns to its routine lifestyle.9

"I certainly think as the mitigation measures as we have in place for COVID come down and kids go back to school in person and we all start traveling again, particularly internationally, we know all sorts of respiratory viruses are going to have much more opportunities to spread," Brammer explained.

University of Michigan School of Public Health epidemiologist Aubree Gordon studies the influenza virus. She told CNN that another reason this flu season may be heightened is due to a decrease in exposure throughout the past 15 months.

"The longer you go without exposure, the more likely you are to be symptomatic and more likely to be sicker. We do know the longer you go without being exposed to influenza, the more symptomatic you are. Sicker individuals lead to more severe cases. We absolutely know that," Gordon said.

Due to a lack of information about the 2020-2021 flu strain, Advisory Board reports that it may be more difficult for scientists to create the vaccine for the upcoming flu season as they typically base the treatment off the previous outbreak. Nevertheless, experts cannot conclude what will lie ahead in the upcoming flu season.

Should people start wearing masks if they have seasonal influenza?

As unmasking across the country continues to happen, some may wonder whether they will have to bring their face coverings back out by the time the 2021-2022 flu season comes around. Establishing masking guidelines for a non-pandemic-related illness is under consideration by scientists and researchers.

The CDC released its “Interim Guidance for the Use of Masks to Control Seasonal Influenza Virus Transmission,” which covers the common procedures recommended if someone has the flu.8 In a healthcare setting, symptomatic patients should wear a mask until they are isolated in a room by themselves. Healthcare officials should also wear a mask if they are within six feet of an infected individual for treatment.

While the guideline is clear about the precautions to take for symptomatic patients, the direction for those outside of healthcare settings or asymptomatic patients leans into a few different measures to take. The CDC recommends putting pharmaceutical and social practices in place to decrease the development of the virus. Personal preventive measures include the proper washing of hands, covering one’s mouth when they are coughing and/or sneezing and practicing social distancing from those who are not sick.

Ultimately, the CDC advises that getting the flu vaccine is the main way to stop the spread of seasonal influenza. While the organization recognizes that those who get their flu shot can still become infected, the chances of experiencing high-risk complications from the virus are low. There are also antiviral medications available for those who are greatly affected by the flu and are hospitalized.

Moving Forward to Protect Others

In order to keep our customers and our community safe from disease, Hardy Diagnostics sells numerous products that can prevent a dramatic spread of viral illnesses in order to protect others in the future. Hardy Diagnostics is an authorized distributor for the Quidel QuickVue lateral flow tests10, with the purpose of diagnosing Influenza A and B. The rapid lateral flow test is CLIA waived and delivers results in just 10 minutes.

When COVID-19 started to spread rapidly across the U.S., Hardy Diagnostics also became a distributor of a rapid test kit that was essential in detecting antibodies related to the SARS-CoV-2 virus.11 The Premier Biotech COVID-19 IgG/IgM Rapid Test Cassette is a lateral flow immunochromatographic assay can detect SARS-CoV-2 antibodies in venous whole blood, serum or plasma. The results are available in only 10 minutes and this test is CLIA waived. This test is also convenient because it does not require any equipment to perform.

As for basic protection from such viral infections, Hardy Diagnostics manufactures and distributes laboratory supplies to help keep everyone safe. These products include sanitizers and cleansers such as AloeSafe™ Antiseptic Hand Sanitizer and personal protective equipment like Exam Gloves and NIOSH-approved N95 masks with a V-fold design. These products, aligned with health guidelines, will allow healthcare workers, caregivers, and the general population to defend themselves against diseases such as COVID-19 and the seasonal flu.

To further support our healthcare heroes and laboratorians, Hardy is continuing to manufacture a room-temperature stable formulation of Viral Transport Media. This is an essential medium to transfer specimens to the laboratory for viral testing methods. Our VTM, R99, is a non-propagating culture media that complies with the CDC formulation and has the room temperature storage capability of 270 days.

At Hardy Diagnostics, we are dedicated to “A Culture of Service,” and our mission is to “partner with our laboratory customers to diagnose and prevent disease.” We are very serious about manufacturing and distributing products that can reduce the spread of viral diseases, such as COVID-19 and influenza.

By Kelly Brickey
Digital Marketing Specialist I
Hardy Diagnostics

References

  1. https://www.cdc.gov/flu/symptoms/flu-vs-covid19.htm
  2. https://globalhealth.harvard.edu/understanding-predictions-what-is-r-naught/
  3. https://sph.umich.edu/pursuit/2020posts/how-scientists-quantify-outbreaks.html
  4. https://newsroom.unsw.edu.au/news/health/what-we-know-about-sars-cov-2-delta-variant
  5. https://www.cdc.gov/flu/weekly/index.htm#S3
  6. https://www.scientificamerican.com/article/flu-has-disappeared-worldwide-during-the-covid-pandemic1/
  7. https://www.arcgis.com/apps/dashboards/bda7594740fd40299423467b48e9ecf6
  8. https://www.advisory.com/en/daily-briefing/2021/03/30/flu-season
  9. https://www.cnn.com/2021/06/08/health/influenza-season-doozy/index.html
  10. https://hardydiagnostics.com/rapid-tests-quidel/
  11. https://hardydiagnostics.com/coronavirus-covid-19-update/