Beginning in 2012, The World Health Organization (WHO) designated the last week of April as “World Immunization Week”. This year, World Immunization Week will take place April 24th-30th with the theme “Protected Together, #Vaccines Work”.[i]
The eradication of smallpox, and the near-global eradication of polio, a disease that decreased by over 99% since 1988, from an estimated 350,000 cases in more than 125 endemic countries to 37 reported cases in 2016[ii], are success stories following global vaccine initiatives.
In a 2008 bulletin from the World Health Organization, the authors recognized 19 discrete individual and societal benefits of vaccination from control of mortality, morbidity and complications to economic benefits, including preventing development of antibiotic resistance.[iii]
Statistics from WHO, July 2017[iv]
- Immunization prevents illness, disability and death from vaccine-preventable diseases including cervical cancer, diphtheria, hepatitis B, measles, mumps, pertussis (whooping cough), pneumonia, polio, rubella, and tetanus.
- Immunization currently averts an estimated 2 to 3 million deaths every year. However, an additional 1.5 million deaths could be avoided if global vaccination coverage improves.
- An estimated 19.5 million infants worldwide are still missing out on basic vaccines.
A current challenge with vaccines is accessibility, and cost is a primary accessibility factor. Some research is focusing on what the lowest dose is to get the necessary immune response, so a production batch will stretch further, thus lowering the unit cost. Adding an adjuvant, a substance that enhances the body's immune response to an antigen, can also stretch a production batch, and the U.S. National Institutes of Health[v] and others are funding development to advance research in this area.
Different methods than the traditional vaccine delivery methods, which include; oral, intramuscular, intradermal, or subcutaneous injection by syringe, are being explored. Costs associated with needle-free injectors have been analyzed[vi] with a positive conclusion. Needle-free injectors use a lower volume of vaccine per dose but use disposable syringes; so there are no ‘sharps’ disposal costs, no potential for ‘needle-stick’ accidents, and no contamination from needle re-use.
Combining different vaccines into one dose, like the Measles – Mumps – Rubella injection, can lower cost to a family for clinic visits, transportation, and time off work.
Another major cost factor is the shipment and storage of vaccines that must be kept at refrigerated or frozen temperatures. Vaccines work by imitating an infection and causing the immune system to produce T-lymphocytes and antibodies, which leave the body with a memory of how to rapidly combat that germ in the future, reducing or preventing symptoms. If the vaccine cold-chain is not maintained, the immune response the vaccine can elicit will be affected. Laboratory and clinical researchers seek to develop vaccines that can be transported at ambient temperatures, increasing accessibility of those vaccines to rural or geographically difficult areas. A microneedle flu vaccine patch is in development[vii] that maintained potency after 12 months at 40°C. The microneedle patch could also save on administration and waste disposal costs.
Current vaccines may not offer protection from all strains of a pathogen, and researchers strive to create ‘universal’ vaccines that can give broad generic protection. For example, Streptococcus pneumonia kills more children than AIDS, malaria and tuberculosis combined.[viii] A current pneumonia vaccine protects against 13 strains, but there are 97 known strains. Australian researchers are using an engineered, cultured, inactivated Streptococcus bacterium to produce a vaccine that shows promise to protect against all pneumonia strains, with the potential to go to market in seven years. Another example is the dengue virus, which has four distinct types. The only currently licensed dengue vaccine is now suspected to provide insufficient protection against all types. An infection with one type can increase the chances of severe reaction when exposed to a second type, so an effective vaccine must protect against all four types at once.[ix] Lastly, seasonal influenza vaccine composition is designed annually to protect against the 3-4 known types projected to circulate that season. It can take six months to produce and distribute. The influenza virus has two types, A and B., Both types can change over time through antigenic drift, small changes as the virus replicates that cumulatively make it unrecognizable to a person’s immune system, and antigenic shift, an occasional mutation in the A type that creates a new sub-type or combination from an animal population that is novel to most immune systems, with potential for pandemic outbreak.[x] The protection given by the vaccine depends on how well the vaccine composition actually matches the seasonal viruses.
Fisher BioServices, a part of Thermo Fisher Scientific, is supporting public health research efforts conducted by the National Institute of Allergy and Infectious Diseases, Division of Microbiology and Infectious Diseases. During the past 23 years, Fisher BioServices personnel have supported protocols involving the adjuvants MF59C.1 and AS03, and innovative and improved vaccines to treat pertussis, cholera, anthrax, tularemia, West Nile virus, malaria, bird flu, swine flu, seasonal flu, and Ebola. This collaboration is currently supporting several Zika vaccine protocols in Puerto Rico, Mexico, Panama, Costa Rica, Peru, Brazil, and the United States.
To learn more about the challenges involved with securing the cold chain and the logistics plan needed to ensure the vaccine's temperature is maintained so it can remain effective, download the case study below. This case study explores a qualified cold chain solution to transport Ebola vaccines to Uganda.