The future of vaccination

In the future, vaccines will offer some of the biggest improvements in public health. Traditional vaccines work by teaching the immune system how to respond to a potential pathogen, using techniques which are not too different from those used by Louis Pasteur a hundred years ago.

However, advances in molecular biology mean that scientists no longer have to inject the entire organism. Instead, they can thoroughly investigate a pathogenic organism to determine which of its components create immunity. For example, whooping cough vaccines have been developed incorporating a small number of the whooping cough bacterium’s components. This potentially reduces some of the side-effects associated with using the entire bacterium as a vaccine.

Expanding technology and an increased understanding of the infecting organisms and the immune system will allow major advances in vaccinology. In the future, new approaches such as inhaled vaccines and injectable DNA vaccines will become available. In addition, countries with less developed health systems will benefit from new delivery forms such as ‘edible vaccines’, genetically engineered into staple foods such as bananas.

The search is underway for an effective vaccine against human immunodeficiency virus (HIV), the cause of AIDS, and there is also the exciting prospect that malaria, one of the world’s major infectious diseases, may be controlled by vaccination.

Therapeutic vaccines are in development that are designed to stimulate the immune system to fight existing disease, rather than preventing a future infection. Three such vaccines – for type 1 diabetes, multiple sclerosis and rheumatoid arthritis – are now listed as ‘most favourable’ candidates and are in development in the USA. Development prospects for an anti-melanoma vaccine are also encouraging.

Many diseases are known to be partly triggered by infectious agents which could be treated with vaccines. The US National Cancer Institute is conducting a large-scale clinical trial of a new human papilloma virus vaccine as an addition to radiotherapy or chemotherapy for the treatment of cervical cancer.

In the paediatric arena, new vaccines are being developed against serious respiratory infections caused by various bacteria and viruses. Vaccines are also being developed to protect against E. coli and the salmonella pathogens which cause food poisoning, the H. pylori bacteria implicated in stomach cancer and gastric ulcers, and for sexually-transmitted diseases such as herpes and chlamydia. Prevention of illness through vaccination means that, one day, these infections may be a thing of the past.