January 30, 2023
The COVID-19 pandemic has had a significant impact on global health and has highlighted the importance of immunization. While COVID-19, the flu, and respiratory syncytial virus (RSV) are all respiratory illnesses, they have some important differences, and it is important for all of us to be aware of these differences and the importance of getting immunized against all three.
As winter approached epidemiologists were strongly predicting that the U.S. would face a rare “triple epidemic” of RSV, Influenza and COVID-19 cases. This winter we are also confronted by a new COVID-19 variant: XBB.1.5. This new covid variant pegged by the World Health Organization as “the most transmissible” descendant yet of the omicron variant, is quickly becoming the dominant strain in the U.S.
Similarities and Differences Among the Three Viruses
COVID-19 is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and was first identified in Wuhan, China in 2019. It has since become a pandemic, with cases identified in nearly every country in the world. The main symptoms of COVID-19 are fever, dry cough, and difficulty breathing, although some individuals may be asymptomatic or have mild symptoms. The virus is primarily spread through respiratory droplets produced when an infected person speaks, coughs, or sneezes. It can also be spread by touching surfaces contaminated with the virus and then touching the mouth, nose, or eyes.
The flu, or “influenza”, is a viral respiratory illness that is caused by the influenza virus. It is characterized by fever, cough, sore throat, muscle aches, and fatigue. The flu is likewise spread through respiratory droplets produced when an infected person talks, coughs, or sneezes. It can also be spread by touching surfaces contaminated with the virus and then touching the mouth, nose, or eyes. While the symptoms of the flu can be similar to those of COVID-19, the flu is generally less severe and is less likely to result in death than COVID-19.
“RSV” is a viral respiratory illness caused by the ‘respiratory syncytial virus.’ It is characterized by symptoms such as fever, runny nose, cough, and difficulty breathing. In the same manner as influenza and COVID-19, RSV is primarily spread through respiratory droplets produced when an infected person talks, coughs, or sneezes. It can also be spread by touching surfaces contaminated with the virus and then touching the mouth, nose, or eyes. RSV is more common in young children and can lead to serious illness. This is particularly true in infants where the bronchial tubes are very small in diameter and the congestion caused by RSV severely restricts the passage of air.
“One to two out of every 100 children younger than 6 months of age with RSV infection may need to be hospitalized. Those who are hospitalized may require oxygen, IV fluids (if they aren’t eating and drinking), and/or mechanical ventilation (a machine to help with breathing). Most improve with this type of supportive care and are discharged in a few days.” cdc.gov/rsv
Immunization is Important
It is important for everyone to get immunized against COVID-19 and the flu., and (when available) RSV to protect themselves and others from these illnesses that can spread at an epidemic rate. COVID-19 vaccines are now widely available and have been shown to be safe and effective in preventing COVID-19. The flu vaccine is also widely available and is recommended for everyone over the age of 6 months. The flu vaccine is not perfect, but it can reduce the severity of the flu and can also prevent hospitalization and death. There is currently no FDA-approved vaccine available for RSV, but research is ongoing and manufacturers are on the verge of releasing new RSV vaccines.
Moderna said it plans to file an application for approval by the Food and Drug Administration in the first half of 2023. In phase three RSV vaccine trials in older adults, “The vaccine was 83.7% effective at preventing lower respiratory tract disease, defined as two or more symptoms, in people ages 60 and older, according to the Boston biotech company. It was 82.4% effective at preventing lower respiratory tract disease with three or more symptoms.”
In addition to protecting individuals from getting sick, immunization also helps to reduce the spread of these illnesses across the population and protect vulnerable populations who may be at higher risk of severe illness or death. This is known as “herd immunity.” When a large percentage of a population is immunized (likely 60-70%), it is less likely for an outbreak to occur, and the virus or illness can have a difficult time spreading. This is especially important for protecting those who are unable to get vaccinated due to age or underlying health conditions (such as a weakened immune system.)
As a country, we have reached “herd immunity” against some formidable viruses, such as rubella and measles. It was thought that the US would get there with Covid-19, but that is probably wrong.
“The concept of classical herd immunity may not apply to Covid-19,” Dr. Anthony Fauci, the recently-retired director of the National Institutes of Allergy and Infectious Diseases, said in an interview with CNN (April 15, 2022.) And that “means we’re not going to be without SARS-CoV-2 in the population for a considerable period of time,” said Fauci, who recently co-authored a paper on herd immunity for the Journal of Infectious Diseases.
It is important for everyone to be aware of the importance of immunization and to take steps to protect themselves and others from COVID-19, the flu, and RSV. This includes getting vaccinated, practicing good hygiene, such as washing hands frequently and covering coughs and sneezes and following guidelines from public health officials. When indoors in tight crowded spaces, the use of a quality face mask is encouraged*. By working together and taking these steps, we can help to protect ourselves and our communities from these illnesses.
**[Reference: Allyson Chiu “Masks and covid-19: Explaining the latest guidance.” The Washington Post, Dec17, 2021.]