The H1N1 virus is full into its second wave all over the world. There has been a large increase over the last 2-3 weeks, including in China. There are some disturbing signs that this H1N1 virus is more dangerous to pregnant women and children than previously thought. With pregnant women, the risk of death from H1N1 is six times higher than the population, and health authorities are stressing that pregnant women get the vaccine. And as for children, already in the US 86 children have died from H1N1, again already a higher total number than we would usually see during the entire seasonal flu season.
And yet there are widespread reports of uncertainty about the H1N1 vaccine. Is there any data to support such fears? The quick answer is no, but let’s talk more about it…
Where’s The Data?
No vaccine is ever 100% safe, but so far this H1N1 vaccine is proving to be as safe as expected — which is to say, very safe. And why wouldn’t it? It is not a completely “new” vaccine, in the sense that it is made the same way as the seasonal flu vaccine, using a similar non-active fragment of the virus. So you would expect the same adverse effect profile.
As for chronic worries by some regarding thimerosal and adjuvants, those issues are moot here, as there are no adjuvants in the H1N1 vaccine nor is there any thimerosal in the single-use vaccines (there is thimerosal in some multi-use vials). Moreover, there continues to be no good evidence linking either thimerosal or adjuvants to increased illnesses.
As for real data on safety, within China, of the 300,000+ initial vaccine group, there are about 100 reported side effects, none serious. That’s considered an even lower side effect profile than the usual seasonal flu vaccine. An earlier report had stated that of the first 39,000 recipients, only 4 had side effects, all mild (muscle cramps and headaches, usually).
There are a lot of websites providing poor information, or latching on to alluring but clinically irrelevant case reports, so it’s best to stick with the most reliable news sources such as WebMD. You can also follow the most reliable tracking of adverse effects from the US CDC and the WHO websites; they have frequent H1N1 updates.
Does the Seasonal Flu Vaccine Help or Hurt H1N1?
You may have read some conflicting news sources over the last couple weeks regarding the seasonal flu vaccine and how it affects H1N1. First, there had been news from an as-yet unpublished Canadian study suggesting that persons vaccinated against seasonal flu were twice as likely to get swine flu. But then a study in Mexico reported the exact opposite finding — that the seasonal flu vaccine actually offers partial protection against H1N1 (here is that original article, published in BMJ). So, who to believe? Well, as this WebMD article discusses, both studies have their flaws, and the overall numbers from other countries still show that there is no cross-over protection to H1N1. And the recommendation remains for those at highest risk to get both seasonal and H1N1 vaccines this year.
Still Not Available in China…Except Schoolkids
Most parents know that the government is offering the H1N1 vaccine to all students over 3, including the expat schools. I personally think this is a great idea, and I hope that parents can assess the real data and say “yes” to vaccination. Unfortunately for us adults, there is as yet still no word as to when the local expat clinics in Beijing will receive the H1N1 vaccine, as the government is allocating these initial stocks. There will be very limited supply for months; even by December there may be enough for only 5% of China’s population. So, China is doing what every country is doing — prioritizing limited supplies for those most at risk. So, stay tuned, and as usual, always practice good prevention. And don’t forget that the seasonal flu vaccine is available now.
Meanwhile, the CDC has updated Q&A about H1N1 vaccine, as well as specific information for pregnant women. The WHO also has their latest update, which specifically mentions concerns that many younger healthy people are ending up in critical care; also, the highest risk patients remain children under 1 and pregnant women.
There is no evidence so far that this H1N1 vaccine is causing any more adverse effects than the regular seasonal flu vaccine. Moreover, the flu season is heating up, and there are some disturbing trends that pregnant women and children under 1 are having more serious illnesses than expected — including death. So, please consider vaccinating your children this week in school, and as the rest of us wait for the H1N1 vaccine, it’s a good idea for those at highest risk to get the available seasonal flu vaccine now. And as we wait, keep up with your best preventive medicine habits!