photo by stevendepolo
Tuesday morning, our local news aired a brief segment on the release of the H1N1 vaccine. They quickly noted who should get the vaccine and who should not. All-in-all, less than 30 seconds were taken to explain this week's release of the H1N1 vaccination. I wanted to know more, and so I started to dig around.
Here are 5 facts I discovered that I want to share with you:
1) The FluMist version of the H1N1 vaccine is what is known as a Live Attenuated Influenza Vaccine. This means that it is made with live, weakened viruses. Because of this, the FluMist version of the H1N1 and the seasonal flu vaccine is not recommended for:
- People less than 2 years of age
- People 50 years of age and over
- People with a medical condition that places them at high risk for complications from influenza, including those with chronic heart or lung disease, such as asthma or reactive airways disease; people with medical conditions such as diabetes or kidney failure; or people with illnesses that weaken the immune system, or who take medications that can weaken the immune system.
- Children less than 5 years old with a history of recurrent wheezing
- Children or adolescents receiving aspirin
- People with a history of Guillain–Barré Syndrome that occurred after receiving influenza vaccine
- Pregnant women
- People who have a severe allergy to chicken eggs or who are allergic to any of the nasal spray vaccine components.
(Source: CDC)
2. Because the FluMist version of the H1N1 and seasonal flu vaccination contains the live virus, it is possible for the virus to "shed" from the vaccinated person to those he encounters. Please note this from the CDC (which speaks to general flu vaccinations, not just the H1N1 vaccination):
Because LAIV contains live influenza viruses, a potential exists for transmission of these viruses from vaccinees to other persons. Vaccinated immunocompetent children can shed vaccine viruses for <3 weeks (6). One unpublished study in a child care center setting assessed transmissibility of vaccine viruses from 98 vaccinated to 99 unvaccinated subjects, all aged 8--36 months. Eighty percent of vaccine recipients shed >1 virus strain, with a mean of 7.6 days duration (17). One influenza type B isolate was recovered from a placebo recipient and was confirmed to be vaccine-type virus. The estimated probability of acquiring vaccine virus after close contact with a single LAIV recipient was 0.58%--2.4%. The type B isolate retained the cold-adapted, temperature-sensitive, attenuated phenotype, and it possessed the same genetic sequence as a virus shed from a vaccine recipient in the same children's play group.
Should you choose the FluMist version of any flu vaccine, you may want to exercise care in thinking about whom you will come in contact with in the days (and possibly weeks?) following vaccination.
3. Speaking of shedding, it's important to remember that everyone infected with any kind of virus will shed that virus for 24 hours after fever subsides, but possibly longer. There is some evidence that the H1N1 virus may shed longer than other influenza viruses:
A similar study of 70 patients by a team headed by Dr. David Chien Lye, of Tan Tock Seng Hospital in Singapore, showed that 80 percent were shedding virus after five days, 40 percent after seven days and 10 percent after 10 days. Both researchers agree that more study is needed to determine the period of time the disease can actually be transmitted, but that patients shouldn't rush to return to work or school.
Source: News-Medical.Net
4. Because pregnant and nursing mothers and children under two are not supposed to receive the FluMist version of the H1N1 vaccine, some health care providers are encouraging these groups to get the injected vaccine. Please note this information from the vaccine manufacturer's (Novartis) insert:
8.1 PregnancyPregnancy Category C: Animal reproduction studies have not been conducted with Influenza A (H1N1) 2009 Monovalent Vaccine or FLUVIRIN. It is also not known whether Influenza A (H1N1) 2009 Monovalent Vaccine or FLUVIRIN can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity. Influenza A (H1N1) 2009 Monovalent Vaccine should be given to a pregnant woman only if clearly needed.8.3 Nursing MothersIt is not known whether FLUVIRIN or Influenza A (H1N1) 2009 Monovalent Vaccine is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when Influenza A (H1N1) 2009 Monovalent Vaccine is administered to a nursing woman.8.4 Pediatric Use
Safety and effectiveness in pediatric subjects below the age of 4 years have not been established. [see ADVERSE REACTIONS (6) and CLINICAL STUDIES (14)]
Essentially, the vaccine is safe for pregnant women, but it is unclear what effects it might have on the unborn baby. It is also unclear what effect it will have on children under four.
This clearly creates quite a predicament for pregnant women. There are some reports that H1N1 is more dangerous for pregnant women than the seasonal flu; however, in my county and in areas across the nation, health care providers are no longer screening for H1N1. It seems to me, then, that this belief that pregnant women are more likely to die from H1N1 may not be entirely accurate because there is no longer an accurate number being reported on how many pregnant women are actually coming down with H1N1.
Again, I would just encourage women to exercise caution.
5. Finally, it is important to note that multi-dose vials of the injected H1N1 vaccine do contain thimerosal. Thimerosal is a mercury-containing compound used as a preservative in some vaccinations. I am not about to engage in the thimerosal-autism debate, and I actually don't want to address whether or not thimerosal is actually toxic in the amount it is found in vaccines. What I do want to do is make you aware that of the nine different H1N1 vaccines (both injected and nasal mist) approved by the FDA, four do contain thimerosal:
- Novartis's single-dose syringe contains a trace of mercury
- Novartis's 10 dose bottle contains 25 mcg of mercury per dose
- CSL's 10 dose bottle contains 24.5 mcg of mercury per dose
- Sanofi Pasteur's 10 full-dose bottle or 20 1/2 dose bottles contain 25 mcg per dose
I hope this provides some helpful information for you in making a decision about whether or not to get the H1N1 vaccine. Each family and individual must weigh the risks of the vaccine against the risks of this strain of influenza. I have said before and I'll continue to say the only bad vaccination decision is an uninformed vaccination decision.
