With the current worldwide vaccination program against the H1N1 flu virus, you may be wondering just what a vaccine is and how it works.

In essence, it’s a substance, usually a protein or carbohydrate, that induces immunity to a disease or infection. You can get immunity to a disease in two different ways.

One is to have the infection and thereafter you have a level of immunity.

The other way is to receive a part of the virus or bacteria that won’t cause an infection, but will allow you to develop antibodies so that when you later get the infection, you will be able to handle it.

The H1N1 flu vaccine falls into the latter category, exposing recipients to a small amount of a purified version of virus, grown in a laboratory, in order to boost the body’s level of resistance to that specific illness.

What is a vaccination and how does it work?
Vaccinations protect you from specific diseases that can make you very sick, disable or even kill you. They boost your body’s own defence system, which is also called the immune system.
Vaccines create immunity that protects you from an infection without causing the suffering of the disease itself.  Sometimes vaccines are called immunizations, needles or shots.

How vaccines work
- Most vaccines contain a little bit of a disease germ that is weak or dead. Vaccines do NOT contain the type of germ that makes you sick. Some vaccines do not contain any germs.
- Having this little bit of the germ inside your body makes your body’s defence system build antibodies to fight off this kind of germ. Antibodies help trap and kill germs that could lead to disease.
- Your body can make antibodies in two ways: by getting the disease or by getting the vaccine. Getting the vaccine is a much safer way to make antibodies without having the suffering of the disease itself and the risk of becoming disabled or even dying.
- Antibodies stay with you for a long time. They remember how to fight off the germ. If the real germ that causes this disease (not the vaccine) enters your body in the future, your defence system knows how to fight it off.
- Often, your defence system will remember how to fight a germ for the rest of your life. Sometimes, your defence system needs a booster shot to remind it how to fight off this germ.
- Sometimes vaccines prevent one disease. Sometimes they are combined to protect you from several diseases with one shot. For example, the MMR vaccine fights Measles, Mumps and Rubella (German measles).

Scientists are looking at new ways to give vaccines, such as by mouth or with nose spray.

Today Q&A about the news that a 14 year old girl died soon after receiving the Cervarix vaccine in the UK.

My view

It’s always sad when someone dies.

I have no objection to the safety of vaccinations. It is a fact that there are risks, but they are remote, especially when compared to the diseases they prevent.  We do not know yet what caused the accident but this is the first death in England.

Any doctor will tell you that death caused by vaccine will be very rare and that since 750 women die from cervical cancer in England every year the benefits outweigh the costs.

One issue does remain, the vaccine has not been proved to work beyond the 5 year period and the vaccine is marketed as working for 5+ years, so there may be a need for vaccinate again all those young girls (see death stats here).

I have to say there are a lot of critics out there. Some will question the success rate of the vaccine, some will question the link between the HPV virus and having cervix cancer, some will attack the marketing techniques, some will say that regardless of the vaccine a yearly review will still be needed, some regard the vaccination program as an experiment. So many more…

Apart from all these views which are well worth listening to,  I am of the view that this vaccine program is worth being undertaken. I just hope a better vaccine will in time be developed  that has lesser side effects.

What happened?

All we know at this stage is that a 14-year-old girl tragically died shortly after being given the vaccine. We do not know her past medical history, and a post-mortem has yet to be held to ascertain the cause of death.

What do we know about the vaccine?

Cervarix vaccine prevents infection with the two commonest types of HPV involved in cervical cancer. HPV stands for Human Papillomavirus.

Cervarix is given in three doses during a six-month period to trigger immune responses that help protect against two strains of HPV responsible for most cervical cancer cases.

The vaccine is approved for females ages 9 to 26. The vaccine has not been tested beyond 5 years so it is not known how long the immunity from the vaccine will last beyond that.

Even with the cervical screening program, in England, each year, there are:

• 21,617 cases of advanced precancerous disease.

• 2,221 cases of invasive cancer of the cervix.

• 899 deaths from cancer of the cervix.

The vaccine will probably prevent around 70% of these. It has been used in this country for just over a year, and more than a million doses have been given. Worldwide, many more doses have been administered with a good safety record.

Here are links to some stats and infor from the NHS

Is the vaccine safe?

The vaccine is safe, there will always be events of bad reactions and some mild to serious side effects.  Since the vaccine was introduced (it is now licensed in over 90 countries), its safety has been monitored very carefully. In spite of millions of doses being given, we haven’t heard of other deaths.

Now i don’t want to appear biased but the side effects do exist.  In the UK, Cervarix has been used for a year now, there have been over 2000 adverse reactions and over 4000 suspected adverse reactions. About 10 of these are so serious that their families are suing Glaxo Smith Kline, the manufacturer of the vaccine. Read here on page 2.

My conclusion is that overall, rarely a person does have a life-threatening allergic reaction after a vaccine and things have not changed with this one.

Could there be a problem with a particular batch of vaccine?

Until we know more, this is impossible to say. However, as a precaution, the batch from which this young girl was immunised (AHPVA043BB).

Should we go on using the vaccine?

The worldwide track record of this vaccine is such that it is most unlikely there is any problem with the vaccine in general.