Research for a safer smallpox vaccine

Research for a safer smallpox vaccine

Reported to have killed over 300 million people in the 20^th century before being ‘eradicated’ in the late 1970’s [1], this global killer is once again the subject of intent scientific study; not because people are contracting the disease but rather due to its potential use as a ‘bioterrorism agent’.

Smallpox (Variola Virus) has a 30% kill rate and given the fact that ‘immunization ceased’ worldwide by 1983, the UPMC Center for Health Security states, “the global population is extremely vulnerable to the disease.”[2]

Fear of smallpox as a biological weapon, has scientists avidly working on replacing ‘conventional antibodies’ with easily transformable, single domain antibodies (sdAbs) which lend also to easier bulk production.

In a 2014 study, “Development and Evaluation of Single Domain Antibodies for Vaccinia and the L1 Antigen,” researchers immunized two llamas with ‘killed viral particles’ (less risky to administer to humans than their alive counterpart)[3] and stimulated them with the L1 antigen to promote a quick ‘immune response’ but found the ‘L1-binding sdAbs’ didn’t recognize the killed vaccinia antigen.[4]

While the scientists were able to isolate the vaccinia from the immunized llamas, and with simple amino acid modifications did find the L1- binding sdAbs to have ‘thermal stability’ (up to nearly 20 degrees Celsius), the “L1 binding sdAbs [did not] bind [to] the viral target”.[4] Therefore not sufficiently replacing the current conventional vaccinia vaccine. However, even though their findings were ‘unexpected’, the results of this study are promising as it does show improvement in detection versus ‘conventional antibodies.’[4]

More research indeed still needs to be conducted for a new smallpox vaccine but one thing is for certain, these researchers found that sdAbs, given their “excellent affinities, specificities and thermal stability, [are] attractive alternatives to conventional mono or polyclonal antibodies.”[4]

References:

1. Smallpox Information and Facts. Retrieved from https://www.nationalgeographic.com/science/health-and-human-body/human-diseases/smallpox/
2. (2014) UPMC Center for Health Security, 2014; Retrieved from http://www.centerforhealthsecurity.org/our-work/publications/smallpox-fact-sheet
3. Bielinska, A. U., Chepurnov, A. A., Landers, J. J., Janczak, K. W., Chepurnova, T. S., Luker, G. D., & Baker, J. R. (2008). A Novel, Killed-Virus Nasal Vaccinia Virus Vaccine. Clinical and Vaccine Immunology : CVI, 15(2), 348–358. http://doi.org/10.1128/CVI.00440-07
4. Walper SA, Liu JL, Zabetakis D, Anderson GP, Goldman ER (2014) Development and Evaluation of Single Domain Antibodies for Vaccinia and the L1 Antigen. PLOS ONE 9(9): e106263. https://doi.org/10.1371/journal.pone.0106263