Many new vaccines have been developed recently to fight against infectious diseases and advanced stages of diseases. Let us first understand what is vaccine. Vaccine contains disease causing organism (either live or dead) to improve the human immunity against a particular disease. These agents stimulates the body's immune system and destroys or kill the cells against the particular disease

Vaccines are of two types :-

1. Prophylactic - These vaccines helps to prevent the future infections
2. Therapeutic - These vaccines act as medicine and helps to reduce the particular disease. Ex - Cancer vaccine are given in cancer patients to fight against the cancer cells. But cancer vaccine is still under investigation.Recently developed new vaccines are

A) Vaccine against Pneumococcal disease ( Prevnar)

Pneumococcal disease is the lower respiratory tract disease and caused by bacteria called Streptococcus pneumoniae.It is a acute disease and causes death of millions of people in a year. This disease is commonly seen in developing countries and young chidren are commonly affected.

The vaccine called Prevnar is developed to fight against the seven strains of pneumococcal diseases. It is a conjugate vaccine which means made by attaching poor polysaccharides organism (antigen) to a carrier proteins and thus confers the immunological attribute of the carrier on the attached antigen. This vaccine has been developed by Wyeth Vaccines and widely used in United States. This vaccine has magically reduced the deaths in USA.
Price of vaccine - The price of vaccine is high especially for the developing countries. People with good economic background can afford the vaccine.

B) Vaccine against Human Papilloma Virus

Human Papilloma Virus is the major cause of sexually transmitted disease and causes cervical cancer. Cervical cancer is common disease in women and kills nearly 75 to 80 % of patients.

The vaccine called Gardasil fights against HPV virus and cervical cancer. HPV causes genital warts and cervical cancer. HPV is spread by sexual contact and hence it is best to vaccinate the people in adolescent age. Still the further studies are going on with respect to HPV vaccine.

C) Rotavirus Vaccine

Rotavirus is responsible for the serious acute diarrheas and causes many deaths in a year in children.Vaccine called Rotarix is developed and effective against the numerous rotavirus strains. Rotavirus vaccine is usually live, oral vaccine and hence it should interfere with polio vaccine. This vaccine has been developed by GlaxoSmithKline.

D) Malaria Vaccine

The vaccine against malaria is currently under the clinical trial. According to some research study only 5 % of volunteers developed immunity against the malaria. The experiment conducted on mice shows if vaccine is administered directly into the blood stream then shows effective results as compared to other administration like skin and body fats.

This vaccine uses the infected mosquitoes. The presence of this infected mosquito stimulates the body's immunity and fight against the infection.
But the problem may arises as the same mosquito can cause many diseases. Still human trials are going on.

E) HIV Vaccine

There is no such effective vaccine against HIV/ AIDS. During the research of SIV ( Simian Immunodeficiency Virus) researcher came across certain type of immune cells called T-helper 17cells (Th17) in rehsus monkeys and they had lower level of virus as compared to others.

SIV is a retrovirus that infects the monkeys and primates. But the strains of SIV is similar to HIV and when same virus infects the humans it is called as HIV.Th17 are effective cells and protect against HIV or SIV. Research team found that the SIV infection causes the weakening of immunity and reduction in the protective activity ofTh17 cells in the gut. Animals with Th17 cells are able to control SIV more better than the ones with less Th17 cells. Hence researches are trying to use the same technique in humans for protection against HIV.