Have you prevented influenza (flu)?

From the Guidelines

To prevent influenza, getting an annual flu vaccine is the most effective method, as it reduces outpatient medical visits for illness caused by circulating influenza viruses by 50% to 75%. According to the recommendations for prevention and control of influenza in children, 2016-2017 1, any licensed and age-appropriate IIV available should be used, as the vaccine strains are predicted to be well matched to circulating strains with the intent of providing optimal protection. The universal administration of seasonal vaccine to everyone 6 months and older is still the best strategy for preventing illness from influenza.

Some key points to consider for flu prevention include:

• Getting vaccinated annually, as the flu virus strains change each season
• Practicing good hygiene, such as washing hands frequently with soap and water for at least 20 seconds
• Avoiding touching your face and staying away from sick people to reduce transmission risk
• Maintaining a healthy lifestyle with adequate sleep, regular exercise, proper nutrition, and stress management to strengthen your immune system

It's essential to note that while antiviral medications like oseltamivir (Tamiflu), zanamivir (Relenza), peramivir (Rapivab), or baloxavir (Xofluza) can be prescribed by healthcare providers to prevent flu after exposure or for high-risk individuals, vaccination remains the best available preventive measure against influenza 1.

In terms of specific vaccine recommendations, the study suggests that any licensed and age-appropriate IIV available should be used, as the vaccine strains are predicted to be well matched to circulating strains with the intent of providing optimal protection 1.

From the FDA Drug Label

The efficacy of oseltamivir phosphate in preventing naturally occurring influenza illness has been demonstrated in three seasonal prophylaxis (community outbreak) clinical trials and one post-exposure prophylaxis trial in household contacts In a pooled analysis of two seasonal prophylaxis trials in healthy unvaccinated adults (aged 18 to 65 years), oseltamivir phosphate 75 mg once daily taken for 42 days during a community outbreak reduced the incidence of laboratory-confirmed clinical influenza from 5% (25/519) for the placebo group to 1% (6/520) for the oseltamivir phosphate group Among household contacts 1 year to 12 years of age not already shedding virus at baseline, the incidence of laboratory-confirmed clinical influenza was lower in the group who received oseltamivir phosphate prophylaxis [3% (3/95)] compared to the group who did not receive oseltamivir phosphate prophylaxis [17% (18/106)] The incidence of confirmed clinical influenza was 3% (7/238) in the placebo group compared with 2% (5/237) in the oseltamivir phosphate group; this difference was not statistically significant. Among subjects who were not already shedding virus at baseline, the incidence of RT-PCR-confirmed clinical influenza infection was 3% (7/231) in the placebo group and <1% (1/232) in the oseltamivir phosphate group

The answer to whether oseltamivir phosphate has prevented influenza (flu) is yes, as it has been shown to reduce the incidence of laboratory-confirmed clinical influenza in various clinical trials, including seasonal prophylaxis and post-exposure prophylaxis trials in adults and pediatric subjects 2.

• Key findings include:
  • Reduced incidence of laboratory-confirmed clinical influenza in healthy unvaccinated adults
  • Lower incidence of laboratory-confirmed clinical influenza in household contacts 1 year to 12 years of age
  • Reduced incidence of RT-PCR-confirmed clinical influenza infection in immunocompromised subjects However, the difference in incidence was not statistically significant in one trial of immunocompromised subjects.

From the Research

Prevention of Influenza

• The use of oseltamivir has been shown to prevent influenza in certain cases, with a study from 3 demonstrating that oral oseltamivir (75 mg once or twice daily for 6 weeks) significantly prevented the development of naturally acquired influenza by >70% compared with placebo in unvaccinated otherwise healthy adults.
• Vaccination is also a key preventive measure against influenza, with the Centers for Disease Control and Prevention (CDC) recommending annual vaccination against seasonal influenza for all persons aged ≥6 months except when contraindicated, as stated in 4 and 5.
• The effectiveness of the influenza vaccine can vary from season to season, with some studies showing lower effectiveness against certain strains of the virus, such as the 16% effectiveness against medically attended outpatient ARI associated with influenza A(H3N2) virus reported in 4.
• Despite variable effectiveness, vaccination is still recommended as it can prevent some infections with currently circulating influenza viruses and reduce the risk of serious outcomes such as hospitalization, intensive care unit (ICU) admission, or death, as noted in 4 and 5.

Treatment and Prophylaxis

• Oseltamivir has been shown to be effective in the treatment of influenza, reducing the duration of symptomatic illness and hastening the return to normal levels of activity when initiated promptly, as reported in 3 and 6.
• The drug has also been used for prophylaxis, with studies demonstrating its effectiveness in preventing influenza in household contacts of infected persons and in high-risk populations such as the elderly or those with chronic cardiac or respiratory disease, as stated in 3 and 6.
• Antiviral medications such as oseltamivir are recommended as an adjunct to vaccination, particularly in cases where vaccine effectiveness is reduced, as noted in 4.