**8. Future horizons in RSV vaccine and RSV therapeutics**

• Continuous struggles are going on for the development of effective and safe RSV vaccines for each target group (infants, children, elders including pregnant women). Previous struggles made to build up a safe vaccine were failed. High antibody production was seen by the use of FI-RSV vaccine in 1960. However, unfortunately vaccinated children developed a severe disease after administration of FI-RSV vaccine. Difficulties and barriers associated with vaccine development particularly live attenuated vaccine are enhanced respiratory disease, maternal antibodies, nasal congestion, low immunogenicity, genetic variability and instability, immature immune system of infants, vaccine virus transmission and immune-senescence as well as preexisting immunity in elders. However, these problems are being slowly overcome [118].


## **9. Conclusions**

One of the most common causes of the respiratory tract diseases is the RSV affecting infants, young children and the elderly people. Only supportive treatment is available such as corticosteroids, bronchodilators, oxygen supplement and ribavirin etc. which may not be occasionally effective. Palivizumab has decreased hospitalization; however, its use is limited due to high cost. Despite it is the era of progress and technology, no RSV licensed vaccine is available in the market to prevent RSV infection. Natural infection also provides partial immunity. A successful vaccine candidate will provide the long term protective immunity and must not lead to induction of enhanced RSV disease. For RSV vaccine development different target groups are being considered such as elders including pregnant women, children and infants. Each of these target groups has different challenges for vaccine development. Maternal antibodies, enhanced disease and immature immune system are the major barriers for vaccine development in the infants. The children >6 months of age have more mature immune system than infants but still can be at the risk of enhanced disease from non-live RSV vaccine. For elderly target population immune-senescence as well as pre-existing immunity is the barrier for vaccine development.

An ideal RSV vaccine should be safe, well tolerated and provide long lasting immunity as compared to natural infection against both RSV strains A and

**87**

*Hurdles in Vaccine Development against Respiratory Syncytial Virus*

B. Further, it is recommended that separate vaccines should be developed for each target group. The tools that ought to enable us to build up a sheltered and successful RSV vaccine are accessible and our challenge is to utilize them wisely. We trust the suggestions for vaccine advancement noted above can support researchers, subsidizing offices, and industry center their endeavors and assets most productively

There is no potential conflict of interest among the authors listed in this

\*, Muhammad Asif Zahoor1

and Muhammad Usman1

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

1 Department of Microbiology, Government College University, Faisalabad,

2 Institute of Microbiology, University of Agriculture Faisalabad, Pakistan

\*Address all correspondence to: drmshafique@gcuf.edu.pk

, Muhammad Hidayat Rasool1

, Muhammad Imran Arshad2

,

,

*DOI: http://dx.doi.org/10.5772/intechopen.87126*

and viably.

manuscript.

**Author details**

Bilal Aslam1

Pakistan

Muhammad Shafique1

Muhammad Usman Qamar1

, Abu Baker Siddique1

provided the original work is properly cited.

**Conflict of interest**

*Hurdles in Vaccine Development against Respiratory Syncytial Virus DOI: http://dx.doi.org/10.5772/intechopen.87126*

B. Further, it is recommended that separate vaccines should be developed for each target group. The tools that ought to enable us to build up a sheltered and successful RSV vaccine are accessible and our challenge is to utilize them wisely. We trust the suggestions for vaccine advancement noted above can support researchers, subsidizing offices, and industry center their endeavors and assets most productively and viably.
