by Dr Pandula Siribaddana

Created on: March 27, 2010

The 2009 H1N1 or else formerly known ‘swine flu’ infection warranted a separate vaccine for its prevention as the usual seasonal influenza shots or the ‘flu shots’ did not cover against the H1N1. Following some unexpected difficulty, the manufacturers came up with two types of vaccines and one was a ‘nasal spray’ made out of a live virus where as the other was a ‘injectable’ or in other words ‘shot’ which was similar to the usual ‘flu shots’.

As mentioned before, the nasal spray vaccine was produced using a live vaccine with attenuated activity which made it less effective in the body temperature than its normal strength counterpart. Due to the presence of a live virus, the vaccine made use of the bodies’ usual immune response to produce a mild version of the illness which is not even sufficient to precipitate influenza like symptoms. But, if the vaccine is given to susceptible individuals of high risk groups for H1N1, it is possible that, there might be a vaccine related H1N1 illness. Therefore, the recommendations are that, the live vaccine should only be given to healthy individuals of the age 2 – 49 years.

The flu shot on the other hand, was developed using a killed virus and therefore is unable to cause an illness among the receiving person of the vaccine. But, it is possible for such individuals to demonstrate certain other symptoms as side effects, which usually are rare and mild. Some of these side effects include,

*Local effects

These include the soreness, swelling, redness...etc that could be seen at the site of the injection and usually would be of mild nature that relieves within 1 -2 days time.

*Systemic effects

It is possible for a person who is receiving the vaccine to develop a mild fever, generalized body aches or malaise for 1 – 2 days and the symptoms will usually begin after 6 – 12 hours following the vaccination.

*Allergic reactions

These are relatively rare and even if it is present, the outcome would be a mild reaction. This can include the appearance of hives, itching…etc. But, it should be remembered that, appearance of an allergic reactions does not necessarily mean that the person should not get the ‘flu shot’ because there are ways for such persons to receive the vaccine.

*Life threatening reactions

As with any other vaccine, the flu shot can give rise to a life threatening reaction, but, its incidence is extremely rare.

In any case, unless the side effects appear as soon as the ‘flu shot’ was given or else after 6 – 12 hours, it is unlikely to be related to the vaccination and will need further medical attention.

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