We at Hyfe, Inc., are a company devoted to working on tools to better understand the importance of cough. It is Hyfe’s intention in the future to seek regulatory approval for medical products that analyze cough in order that they may be used to diagnose, monitor, and facilitate better treatment of respiratory illnesses.
Currently, only two vaccines for respiratory viruses are available – the influenza vaccine and the COVID-19 vaccine.
These respiratory vaccines are especially useful among those who have a chronic illness, along with high-risk groups, such as young children, pregnant women, and adults above 65 years of age. All these groups may have a more difficult experience if they contract a respiratory disease. Additionally, with more people vaccinated, viral spread declines over time as it has fewer people to infect, limiting the number of positive cases every season.
However, viruses evolve based on the immune status of a population. The influenza virus is particularly known for this. This is often why new vaccines are developed to boost immunity toward developing viral strains.
To understand how vaccines work, learning more about vaccine development is important. We can divide them into six sources1.
These are vaccines made from an attenuated (weakened) form of the virus. Exposure to these vaccines prompts a significant immune response from your body. This means that if the actual vaccine tries to infect you, your immune system will know how to mount a very strong defense. Frequently, one or two doses are sufficient for significant immune protection.
These types of vaccines use the killed version of the virus. While it will still result in an immune response, the intensity of the response will not be as strong as that prompted by a live vaccine. Therefore, several doses of an inactivated vaccine are typically required for your immune system to mount a significant response.
These varieties of vaccines are made from different parts of the virus, such as specifically the disease-causing part. Recombinant vaccines use genetic engineering to produce proteins or other antigens of the virus to be used in vaccines. Similar to inactivated vaccines, these vaccines may require several booster doses to result in the desired, ongoing immune response, although the responses they do prompt from your body are usually strong. They are suitable for people with weakened immune systems whose systems may not be able to handle a live vaccine.
Some viruses produce toxins, and it is these which are the primary disease-causing product of such a virus. These toxins can elicit an immune response. So certain vaccines are made only of these specific viral toxins and no part of the actual virus.
This type of vaccine has successfully been used during the COVID-19 pandemic. While these vaccines have been researched for a while, it has only recently been used as a vaccine variant. mRNA is present in all our cells – our DNA uses mRNA to tell the cell to make certain proteins. Viruses hijack this and use their own mRNA to make our cells produce the proteins the virus wants. The mRNA vaccine makes our cells produce these viral proteins, but without the virus being present, so your immune system can recognize them more quickly if you get infected.
This is also a new vaccine technology that has been studied for decades and has recently been successfully used. These use another virus to deliver the intended virus during the immunization. Measles, influenza, and adenovirus are among the vectors used in these types of vaccines2. Viral vector vaccines have been used for COVID-19 and Ebola virus outbreaks. Its benefit is being researched for Zika and HIV.
Ultimately, regardless of the type of vaccine, after a form of infection is introduced into the body through vaccination, the body works to build an immune response to protect from the virus. This induced immune response will not be as severe as the actual infection, but it helps to facilitate the development of immune cells, such as the B and T lymphocytes, required to fight infection. The memory of the immune system then stores these cells.
A Basic Understanding of How Vaccines Work
Image Source: Sanofi Pasteur
Since the initial vaccine exposure may not produce the desired level of effect, we often get second and third doses. Following this, you can get a booster after a few years. These subsequent doses intensify immune responses to a particular virus.
When exposed to the virus, since the immune system has already built up its defenses following the vaccination, it minimizes the impact of the viral infection. This is why some people are asymptomatic even after exposure.
Currently, there are two vaccines for respiratory viruses.
You can get the influenza viral vaccine (seasonal flu shot) every year. There are many different strains of the influenza virus that you could get. The available flu shot for a particular year protects against the top four influenza viruses likely to be a source of infection during the coming flu season3.
Live attenuated and inactivated vaccines are the two most common varieties of vaccines available for influenza. The live attenuated vaccine is frequently recommended for those who have strong immune systems, do not have a chronic illness, and are not immunocompromised. Inactive vaccines are more suitable for immunocompromised and pregnant people4, who are at a higher risk of adverse events from live vaccines.
For the elderly (above 65 years of age), an adjuvant vaccine has recently been approved, which has been shown to prompt a stronger immune response compared to the inactive influenza vaccine5. This is especially useful since elderly people are a high-risk demographic for the flu.
The COVID-19 pandemic facilitated the development of the second respiratory virus vaccine. Almost 70% of the world population has received at least one dose of the COVID-19 vaccine6.
Three variants of the COVID-19 vaccines are approved for use in the US, an mRNA vaccine, a subunit vaccine, and a vector vaccine7. A few countries have also used an inactivated version of the virus for their vaccines 8 9.
A lot of trials are in their final stages to prove the efficacy of the various COVID-19 vaccines. This is why not all of them have been approved and even used during the pandemic. While the viral spread has appeared to slow down, new variants continue to emerge which might require a change in vaccination strategy.
While currently only vaccines for these two respiratory viruses are available, another disease is in the crosshairs. The respiratory syncytial virus (RSV), a common culprit for respiratory infections, also has trials going on for potential vaccines10. This could prove beneficial, especially for high-risk groups where the potential for severe disease and subsequent increased risk of death is possible11.
Here are the common concerns people have when it comes to vaccines. We will then go through each of them in turn:
A primary concern related to vaccines is their safety and potential side effects. Before going in for a vaccination, many people read up on their side effects, such as fever, pain, and other immune responses, which often pose the question as to whether vaccines are safe or not.
With a weakened form of the virus being present in live-attenuated vaccines, it is possible to have a slight fever, runny nose, and soreness due to your body’s immune response to the weakened virus. Most of these subside on their own in a few days. Inactivted, subunit, conjugate, polysaccharide, recombinant, toxoid, and mRNA vaccines do not contain versions of the virus that can infect you.
The most serious effect of vaccinations is anaphylaxis, which is a heightened allergic reaction to components in the vaccine. We see this reaction more frequently among children. However, this level of allergic reaction is extremely uncommon. Studies indicate only about 1.31 cases per million doses of possible anaphylactic reactions12 – that’s 0.00000131%.
Another concern has been the proposed link between vaccines and autism. This was a cause of concern due to a 1998 Lancet report, observing pervasive developmental disorders following the MMR vaccine, which has since been retracted13) – i.e. withdrawn. Studies have since proven there is no causal link between vaccinations and the development of autism14.
Other myths related to vaccinations are also around. They include immune system overload or, conversely, immune system weakening. Immune system overload is the fear that a person’s immune system, particularly a child’s, will not respond properly when receiving multiple vaccinations at once. It is often related to the immune system weakening, which is the fear that the immune system will be more vulnerable to infections in the period after receiving a combined vaccine or multiple vaccinations.
In reality, an immune system can handle up to 10,000 vaccines at once, immunizations give a boost to the immune system, and they do not hamper other immune responses either occurring after vaccination or in the future15.
Another myth that circulated while the COVID-19 vaccine was in use was whether that the vaccine was capable of altering our DNA. Since both the mRNA and vector vaccines required the body to mount a response based on the processing of genetic material, some thought it alters DNA. This is a myth, and there is no change in host DNA following vaccination16.
Currently, there are two respiratory viruses for which vaccinations with approval for use: the influenza virus and the COVID-19 virus.
A third disease, respiratory syncytial virus, is under research for potential vaccine development.
Based on the immune status of a population, virus strains evolve. These viral strains can evade basic immunity, including those resulting from a vaccine for a different strain. So vaccinations can be slightly ineffective against newer strains, but offer more protection than no vaccine at all. This is why newer vaccines, especially in the case of influenza, are developed each year based on currently spreading strains of a virus.
In short, yes.
Aging immune systems might not mount as strong an immune response as expected from a vaccine. This has been showcased during the COVID-19 immunization efforts, where older individuals didn’t report as many effects from vaccinations, often due to lower antibody levels following vaccines. However, this is multifactorial, and changes to vaccines, such as increased antigen loads, can be considered alternatives to prompt the immune system to mount a sufficient immune response.
Yes, respiratory viruses have treatments to help relieve symptoms and help the body fight the infection, including both viruses with available vaccines. However, these are only symptomatic to prevent disease progression. In the case of the influenza virus, the effectiveness of medications is observed within 24-48 hours following symptom onset. Similarly, for COVID-19, treatment should be initiated within a few days of symptom onset to be most effective.
Immunity can last anywhere from six months to two years, which is often why booster shots are recommended, especially for high-risk groups. Influenza vaccinations are taken every year since new strains are often circulating during each season. Immune responses from COVID-19 vaccinations seem to have waned around eight months but still offer notable protection versus not being vaccinated19.
You can take influenza vaccines yearly. Doctors may recommend a booster dose for those with compromised immune systems. Similarly, for COVID-19, booster doses are recommended around two months after the last dose of the vaccine. It can be taken based on requirements and alteration in immune status, usually at the discretion of your primary healthcare provider.
Both viral vaccines are safe for children above six months of age. However, not all COVID-19 vaccines are for babies. Check with your primary care physician on which vaccine will be suitable for your baby.
Your immune system is what protects you from all infections. Having a strong immune system can often help tackle infections before you get the vaccine. This is why some who get viral infections may be asymptomatic or have few symptoms even without vaccination. The main focus of vaccinations is to give your immune system a boost so that it is capable of fighting any infections, especially those which have severe health consequences.
Vaccines for respiratory viruses are protective and significantly help reduce disease spread, which is the main reason for severe outcomes during viral epidemics. Due to the genetic makeup of viruses and their ability to easily mutate into resistant strains, developing vaccines takes time and rigorous trials for effectiveness. However, vaccines against any virus help to protect from severe medical outcomes often as a result of respiratory disease and are worth receiving once developed. These vaccines are easily accessible at your local hospitals and clinics. Discuss your health concerns and possible risk factors with your healthcare provider before getting vaccines.References
Michelle is a healthcare consultant and content creator with over six years of experience in the FemTech space. She contributes extensively to health forums, especially those centered on enabling wellness, advancing digital health, and FemTech solutions. She loves classic rock music, reading classic literature, and finding new spots in town for good food and some chai.