FA16 Immunization Module’s Updates

Live vs inactivated vaccines - weighing the pros and cons

As we have all read, live and inactivated viruses are both used for vaccines with each type having its own benefits. Summarizing the CDC Principles of Vaccination, live samples are able to replicate and thus can be administered only once. Inactivated samples are grown in culture and inactivated by heat or chemicals which removes the ability of the pathogen to replicate. Therefore, inactivated vaccines typically require multiple doses to achieve immunity. Furthermore, immunity may diminish over time depending upon the vaccine, and booster shots may be needed. Live vaccines seem to be the clear choice; however, live vaccines may easily be damaged from light or heat. Live vaccines may also pose a threat by eliciting reactions in immunodeficient people.

From these basic descriptions of vaccine production, it would seem that inactivated vaccines are the best solution as they are more durable for transport with minimal risk of reaction. However, the delivery of vaccines must be thought about as well. The polio vaccine is a prime example of this. The United States has eliminiated polio since 1979. However, lesser developed countries are not as fortunate. The United States is lucky enough to have a well developed health care system that allows for easy access to clinics for vaccinations. As such, there is little risk of a patient not completing a vaccination protocol. In areas where health care is limited such as Somalia or Sudan, this is not an option, and children are forced to consume the oral polio vaccine. In addition to the risk of reaction described above, the polio vaccine is the only vaccine in which a vaccination may revert into its pathogenic form resulting in paralysis. While the risk of reversion is low, paralysis from polio is a drastic side effect which is even more difficult to manage in undeveloped countries. Furthermore, seeing someone become paralyzed after receiving a vaccination can produce fear of vaccines (and for good reason too).

Vaccination still needs to occur as the risk of contracting polio through the oral vaccination is lower than without the vaccine though the modality of vaccination is not always clear. There are other variables such as cost and ease of administration. A shot requires a degree of expertise while oral administration of the vaccine is quite simple. In areas where patients far outnumber medical personnel, oral vaccinations may seem to be the only option as achieving herd immunity can greatly impair the spread of a pathogen. For those who decide to take their medical talents abroad, be sure to carefully evaluate vaccine delivery options to see what really is best for your patients.

Sources:

http://www.chop.edu/centers-programs/vaccine-education-center/vaccine-details/polio-vaccine#.V-ssligrKUk

https://www.cdc.gov/vaccines/pubs/pinkbook/downloads/prinvac.pdf

  • Daniel Cibich