Originally posted by: Looney
Originally posted by: child of wonder
"The flu" is a common misnomer. Gastrointestinal viruses are what cause what we commonly refer to as "the flu." It's symptoms are fever, vomiting, diarrhea, etc.
I have never in my life, or anybody i know, ever refer to gastrointestinal viruses as 'the flu'.
Dubunking the half truths by amused:
http://www.cdc.gov/flu/about/qa/disease.htm
What is influenza (flu)?
Influenza, commonly called "the flu," is caused by the influenza virus, which infects the respiratory tract (nose, throat, lungs). Unlike many other viral respiratory infections, such as the common cold, the flu causes severe illness and life-threatening complications in many people.
What are the symptoms of the flu?
Influenza is a respiratory illness. Symptoms of flu include fever, headache, extreme tiredness, dry cough, sore throat, runny or stuffy nose, and muscle aches. Children can have additional gastrointestinal symptoms, such as nausea, vomiting, and diarrhea, but these symptoms are uncommon in adults.
Although the term "stomach flu" is sometimes used to describe vomiting, nausea, or diarrhea, these illnesses are caused by certain other viruses, bacteria, or possibly parasites, and are rarely related to influenza.
child of wonder has some very valid points.
SacrosanctFiend is also correct.
http://www.cdc.gov/flu/professionals/vaccination/composition0607.htm
Both the inactivated and live, attenuated vaccines prepared for the 2006--07 season will include
A/New Caledonia/20/1999 (H1N1)-like, A/Wisconsin/67/2005 (H3N2)-like, and B/Malaysia/2506/2004-like antigens (for the A/Wisconsin/67/2005 [H3N2]-like antigen, manufacturers may use the antigenically equivalent A/Hiroshima/52/2005 virus, and for the B/ Malaysia/2506/2004-like antigen, manufacturers may use the antigenically equivalent B/Ohio/1/2005 virus). These viruses will be used because they are representative of influenza viruses that are anticipated to circulate in the United States during the 2006--07 influenza season and have favorable growth properties in eggs.
Because circulating influenza A (H1N2) viruses are reassortants of influenza A (H1N1) and A (H3N2) viruses, antibodies directed against influenza A (H1N1) and influenza (H3N2) vaccine strains should provide protection against the circulating influenza A (H1N2) viruses.
http://www.cdc.gov/flu/professionals/vaccination/laivefficacy.htm
The immunogenicity of the approved LAIV has been assessed in multiple studies, which included approximately 100 children aged 5--17 years and approximately 300 adults aged 18--49 years. LAIV virus strains replicate primarily in nasopharyngeal epithelial cells. The protective mechanisms induced by vaccination with LAIV are not completely understood but appear to involve both serum and nasal secretory antibodies. No single laboratory measurement closely correlates with protective immunity induced by LAIV.
Healthy Children
A randomized, double-blind, placebo-controlled trial among 1,602 healthy children initially aged 15--71 months assessed the efficacy of trivalent LAIV against culture-confirmed influenza during two seasons. This trial included subsets of 238 healthy children (163 vaccinees and 75 placebo recipients) aged 60--71 months who received 2 doses and 74 children (54 vaccinees and 20 placebo recipients) aged 60--71 months who received a single dose during season one, and a subset of 544 children (375 vaccinees and 169 placebo recipients) aged 60--84 months during season two. Children who continued in the study remained in the same study group.
In season one, when vaccine and circulating virus strains were well-matched, efficacy was 93% for participants who received 2 doses of LAIV. In season two, when the A (H3N2) component was not well-matched between vaccine and circulating virus strains, efficacy was 86% overall. The vaccine was 92% efficacious in preventing culture-confirmed influenza during the two-season study. Other results included a 27% reduction in febrile otitis media and a 28% reduction in otitis media with concomitant antibiotic use. Receipt of LAIV also resulted in 21% fewer febrile illnesses.
A review of LAIV effectiveness in children aged 18 months--18 years found effectiveness against MAARI of 18% but greater estimated efficacy levels: 92% against influenza A (H1N1) and 66% against an influenza B drift variant.
Healthy Adults
A randomized, double-blind, placebo-controlled trial among 4,561 healthy working adults aged 18--64 years assessed multiple endpoints, including reductions in self-reported respiratory tract illness without laboratory confirmation, absenteeism, health-care visits, and medication use during peak and total influenza outbreak periods. The study was conducted during the 1997--98 influenza season, when the vaccine and circulating A (H3N2) strains were not well-matched. During peak outbreak periods, no difference in febrile illnesses between LAIV and placebo recipients was observed. However, vaccination was associated with reductions in severe febrile illnesses of 19% and febrile upper respiratory tract illnesses of 24%. Vaccination also was associated with fewer days of illness, fewer days of work lost, fewer days with health-care--provider visits, and reduced use of prescription antibiotics and over-the-counter medications. Among a subset of 3,637 healthy adults aged 18--49 years, LAIV recipients (n = 2,411) had 26% fewer febrile upper-respiratory illness episodes; 27% fewer lost work days as a result of febrile upper respiratory illness; and 18%--37% fewer days of health-care--provider visits caused by febrile illness, compared with placebo recipients (n = 1,226). Days of antibiotic use were reduced by 41%--45% in this age subset.
A randomized, double-blind, placebo-controlled challenge study among 92 healthy adults (LAIV, n = 29; placebo, n = 31; inactivated influenza vaccine, n = 32) aged 18--41 years assessed the efficacy of both LAIV and inactivated vaccine.
The overall efficacy of LAIV and inactivated influenza vaccine in preventing laboratory-documented influenza from all three influenza strains combined was 85% and 71%, respectively, on the basis of experimental challenge by viruses to which study participants were susceptible before vaccination. The difference in efficacy between the two vaccines was not statistically significant.