Types of Seasonal Influenza Vaccines
There are a few main types of seasonal influenza vaccines available each year depending on age and health status. The most common types include:
- Quadrivalent influenza vaccines: These vaccines protect against four different strains of flu virus (two influenza A viruses and two influenza B viruses). They are recommended for everyone aged 6 months and older. The quadrivalent vaccines are available as a shot or nasal spray.
- Trivalent influenza vaccines: These older Seasonal Influenza Vaccines protect against three different flu virus strains but only contain two influenza A viruses and one influenza B virus. They are still used but quadrivalent vaccines are preferred.
- High-dose flu shot: This specialized flu shot is designed for people aged 65 and older. It contains four times the antigen (the material that stimulates the immune response) of a standard-dose flu shot in order to create a stronger immune response in older individuals.
- Cell-based flu vaccine: A newer type of flu shot that is produced using animal cell cultures instead of fertilized hen eggs. This may produce a more potent immune response than egg-based vaccines. It is approved for people aged 18 years and older.
Effectiveness of Seasonal Flu Vaccines
How well seasonal flu vaccines work can vary each year depending on several factors:
- Virus strains: The flu viruses included in the vaccine must match the strains that are actively circulating during the upcoming flu season. Effectiveness is lower in years when there is a mismatch between vaccine and circulating strains.
- Individual characteristics: Things like age, underlying health conditions, and immune status play a role. Vaccines typically work best among healthy younger adults and children. Effectiveness tends to be lower in older adults and those with weakened immune systems.
- Type of vaccine: Some vaccine types like the high-dose shot and cell-based shots may provide better protection than standard flu shots, especially for older age groups.
On average, seasonal flu vaccines reduce the risk of flu illness by 40-60% among the overall population when the vaccine strains are matched well to circulating viruses. However, it also helps reduce severity of illness in those who do still get sick after vaccination.
How Flu Vaccines Help Protect Others?
Getting vaccinated against seasonal flu not only protects oneself but also benefits the community through "herd immunity":
- Reduced spread: Vaccinated individuals who become exposed are less likely to get infected or transmit the virus if they do not develop symptoms themselves. This helps curb spread from person to person.
- Protection of vulnerable groups: When more people in the community are vaccinated, it creates a barrier of protection around those who cannot get vaccinated or do not mount an adequate immune response to vaccination, such as young infants or the immunocompromised.
- Fewer healthcare visits: By preventing many cases of flu illness, vaccines can help lessen the strain on healthcare resources during peak flu seasons so the system has more capacity to treat other patients. This reduces the chance of other illnesses spreading in healthcare facilities as well.
Who Should Get Vaccinated and When?
Seasonal influenza vaccination is recommended for everyone aged 6 months and older unless they have specific contraindications. This includes:
- All children aged 6 months to 18 years
- Adults over 50 years
- Pregnant women
- Those with certain chronic health conditions
- Healthcare workers
- Essential works like teachers, police officers, etc.
The best time to get vaccinated is in the late fall before flu activity begins increasing in communities, usually from October through November. However, as long as flu viruses are still circulating, it's not too late to get vaccinated even into January or later. Getting vaccinated early offers the best protection by allowing time for full antibody development.
Safety of Seasonal Influenza Vaccines
When administered according to recommendations, the seasonal flu shots and nasal spray vaccines have an excellent safety profile and are generally well-tolerated. The most common side effects include:
- Soreness and redness at the injection site
- Low-grade fever
- Muscle aches
- Headache
More severe side effects are very rare. The benefits of vaccination far outweigh the risks of getting sick with influenza. People with egg allergies can safely receive egg-based flu shots as long as they do not have a history of anaphylaxis. Anyone with questions should consult their healthcare provider. On average, seasonal influenza results in hundreds of thousands of hospitalizations and tens of thousands of deaths each year in the United States. Vaccination remains the best way for individuals to protect themselves and reduce community spread during flu season.
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Ravina Pandya, Content Writer, has a strong foothold in the market research industry. She specializes in writing well-researched articles from different industries, including food and beverages, information and technology, healthcare, chemical and materials, etc. (https://www.linkedin.com/in/ravina-pandya-1a3984191)
