Podcast from CBC's White Coat Black Art regarding H1N1

White Coat Black Art (WCBA) is an interesting CBC Radio program prepared by Dr. Brian Goldman. The following is a link to WCBA's podcast regarding the H1N1 pandemic, broadcasted on September 19, 2009.



http://podcast.cbc.ca/mp3/whitecoat_20090919_20419.mp3



You can find all podcasts of WCBA at www.cbc.ca/podcasts



Happy listening.

My decision for H1N1 Vaccination

Should I get H1N1 vaccination? Most people (especially if they are not in the high risk group) are asking this question. Public Health officials are pushing for vaccination but there is not enough vaccine out there for everybody. Supplier firm over-represented the volume they can produce, and health officials likely underestimated the impact of their social advertising on people and this resulted in short supply of vaccine. Should I get worried?

Here is my take of the situation. I believe that my family and I will get vaccinated eventually, unless we get H1N1 before our turn for vaccination. I am not panicking about this and I also think that nobody who does not not have underlying health conditions should. The following presents why I made this decision, hopefully it would help you to make your decision too.

What is the Problem here?

New Scientist writes that H1N1 is a virus that has been circulating since 1889. It is believed that 1918 Spanish flu was also an H1N1 virus and killed 50 Million people (3% of world population) and 1/3 was infected. In 1918, 1 in every 10 infected people died. Most deaths were due to secondary bacterial lung infections. This is before the time of antibiotics. The first modern antibiotic Penicillin was found in 1928 and mass produced in 1942. The rate of H1N1 infection (and consequently number of deaths) would be significantly less now both because of our ability to deal with secondary infections and also the vast improvements in hygiene.

H1N1 circulated until 1957 therefore it is believed that people who were born before 1957 has natural immunity. H1N1 was dormant until 1976; in the same year a strain of H1N1 jumps the species barrier, from pigs to humans resulting in a mass vaccination campaign. The predecessor of 2009 H1N1 appears in 1998 as a combination of human, pig and bird flu viruses.

H1N1 is a highly contagious virus but it is not a deadly one. It affects younger people because older generations possibly have immunity to the virus through past epidemics. The current strain of H1N1 is living together with seasonal influenza (H2N3) and this indicates to me that H1N1 is here to stay for a while.

US CDC estimates that for every confirmed case, there is likely a median of 79 actual people infected with the virus. By the end of October, in Canada, 22,000 people tested, of those 14,860 of them had Influenza A, and 9,418 were H1N1.

Of the H1N1 infections 948 were hospitalized, 147 were admitted to ICU and 24 were died. Of the 24, only 2 were announced to have no secondary health problems. If there were 9,418 confirmed H1N1 cases, based on CDC’s research approximately 744,000 Canadians were infected with H1N1. So if you are healthy and get H1N1, then your risk of dying from H1N1 is 1 in 370,000. If you have secondary conditions than your chance of dying from H1N1 is 1 in 33,000. Of course, these are very broad estimates.

In 1976, 48 million people were vaccinated against H1N1 and 532 people got Guillain-Barre Syndrome and 25 died. The risk of Guillain-Barre syndrome was 1 in 90,000 people and except for 25 all recovered. The risk of Guillian-Barre with current day flu vaccines is no more than 1 in 1,000,000. Over the 33 year period, vaccine production technology has also improved.

During the initial tests before the release of the H1N1 vaccine, 96 percent of people who were vaccinated against H1N1 developed immunity within 21 days after vaccination. The short term complications of H1N1 were local swelling and inflammation; no serious complications were reported. After millions of doses dispended, there may be a better idea of the vaccine complications in the coming months.

The last question I have is the use of Tamiflu (Osteltamivir) for treatment of H1N1. Osteltamivir shown to reduce the length of the flu (not H1N1) from 5.3 days to 4.4 days and reduced flu related complications by 11 percent. Another study showed that Osteltamivir reduced the non-bacterial pneumonia by 4 percent. For ease of calculation and the reason of death in H1N1 infections is the non-bacterial pneumonia, I will consider that Osteltamivir reduces the risk of death by 5 percent. In terms of complications of Osteltamivir, 5 percent of children developed who took Osteltamivir developed vomiting. Other complications included gastrointestinal symptoms, diarrhea, headache, tiredness and difficulty in concentration.

My Objective

My objective is to reduce harm that can be caused by H1N1 flu.

Alternatives and Consequences

1. Take the risk to get the flu: Possibility of infection is 1 in 30 but I will estimate somewhere between 1918 Spanish flu and current status, and use 1 in 15; dying from it 1 in 370,000. Therefore, my overall risk of death from H1N1 is 1 in 5.55 million.

2. Take the risk to get the H1N1 but use Osteltamivir to reduce the impact of the disease: If Osteltamivir makes a 5 percent improvement in non-bacterial pneumonia, lets assume that it would be reducing the risk of dying by the same amount, therefore dying from H1N1 would be 1 in 5.827 million with possible complications between 5 to 10 percent of vomiting, gastrointestinal problems, and may be additional headache.

3. Get vaccinated: Possibility of having a serious complication is 1 in 1 million, likelihood of dying from H1N1 is 1 in 111 million. Only 4 percent might get infected with H1N1, and their likelihood of death is 1 in 5.55 million.

If you look at risk of death, vaccination reduces the likelihood of death by 22 times. It is beneficial to get vaccinated and I decided to get vaccinated. But if you are comparing the dis-ease that H1N1 would cause versus the likelihood of serious vaccine complication (1 in 1 to 2 million), then it becomes a value judgement which one must include questions like "would I contact with people who has secondary conditions?" because they are 10 times more vulnerable to disease then people without secondary conditions. In addition, the fewer the number of people vaccinated, the more likely more people get infected and H1N1 will be around longer as infection would be able to find people without immunity.

People also worry about the adjuvant in the vaccine. Non-adjuvant vaccine will be available but it is likely that the effectiveness of the vaccine would decrease. The decision to wait for non-adjuvant vaccine can not be effectively made until vaccine effectiveness and comparison against possible short term and long term complications of adjuvant are available. My preference is to get non-adjuvant vaccine, if available, which may require me to have two shots rather than one.

Good luck with your decision.