How effective is the ‘flu vaccine?

Every year, come autumn, there is debate around the dinner table about the ‘flu vaccine’.

As it’s getting to that time of year again, when the dreaded influenza virus wreaks havoc on old and young, big and small, YEI decided to get the opinion of the experts.

The World Health Organisation, together with their partners, monitor influenza and its strains globally, and every year, highly recommends a seasonal influenza vaccination and assists in developing prevention and control strategies.

According to the WHO, some of the key facts are:

• This is an acute viral infection that spreads very easily from one person to another;
• ‘Flu can affect anyone at any age, and can cause severe illness and death in higher risk groups;
• ‘Flu can cause epidemics that strain the Health Services and takes its toll through lack of workforce productivity;
• Vaccination is the most proven and effective way to prevent infection in the first place.

YEI spoke to Professor Gillian Ainslie, Acting Head of the Respiratory Clinic at Groote Schuur Hospital and the University of  Cape Town:

Who should be vaccinated? 

Persons who are at high risk for influenza and its complications:

• Adults and children older than 6 months with underlying medical conditions (chronic lung, cardiac,  neurological and renal diseases, diabetes mellitus, immunosuppressed people including HIV-infected persons  with CD4 counts above 100 cells/μl, and children on chronic aspirin therapy)
• Residents of old age homes and chronic care and rehabilitation institutions
• All people 65 years of age or older
• Some countries recommend routine immunisation of all young healthy children from 6 months to 6 years of age
• Women who would be in the second or third trimester of pregnancy during the influenza season
• Adults and children who are family contacts of high-risk cases
• Medical  and nursing staff responsible for the care of high-risk cases
• Essential services personnel (emergency and security personnel), and people who live or work in special circumstances (e.g. mine, military, dormitory, large workforces, etc.)
• Any persons wishing to protect themselves from the risk of contracting influenza, especially in industrial settings, where large-scale absenteeism could cause significant economic losses

 Are there any groups of people who should avoid the ‘flu vaccine?

• Persons with a history of severe hypersensitivity (allergy) to eggs
• Persons with acute febrile illnesses should preferably be immunised after symptoms have disappeared
• The vaccine should be avoided in the first trimester of pregnancy unless there are specific medical indications

 Are there any risks involved in terms of people having the vaccination?

• Rarely there can be allergic reactions, more likely to occur in people with egg allergy (because the vaccine is developed in eggs).
• Otherwise there may be some pain related to the injections. It cannot cause influenza as the viral content is inactivated. People who think that it has in the past most likely had a similar but different viral infection (there are many viruses which give flu-like symptoms).

 Does the benefit of having the vaccination outweigh the risks?

• Yes, particularly in the groups listed above.
• Vaccination should be given early in the year to provide protection for the autumn and winter. A protective antibody response takes about 2 weeks to develop. However, vaccination can be done at any time of the season, even until late winter.