Future Developments in Vaccines and Their Delivery

Diseases Newly Vaccine-Preventable Since 1980

Hepatitis B: (vaccine U.S. licensed in 1981) Causes hepatitis, cirrhosis and liver cancer.
Haemophilus influenzae type b: (1985) Causes meningitis and other serious illnesses.
Hepatitis A: (1995) Causes hepatitis.
Varicella: (1995) Causes chickenpox and its occasional serious side effects.

Diseases Expected to Become Vaccine-Preventable in Coming Years

Rotavirus: Major cause of diarrhea and hospitalization in infants.
Lyme Disease type b: (1985) Tickborne disease causing fever, rash, arthritis and other complications.
Respiratory Syncytial Virus: Major cause of serious lung infections in infant.
Herpes Simplex Virus: Sexually-transmitted disease causing painful ulcers.
Human Papilloma Virus: Sexually-transmitted disease causing cervical cancer.
Pneumococcal Disease in Infants: Common cause of ear, lung and other infections.
Meningococcal Disease in Infants: Causes meningitis and bloodstream fections.

Some Existing Injectable Combination Vaccines Used in Childhood Immunization

MMR Measles, mumps and rubella.
IPV Inactivated polio vaccine against poliovirus types 1, 2 and 3.
DTwP / DTaP / DTwP-Hib / DtaP-Hib Diphtheria and tetanus combined with either whole-cell or acellular pertussis (whooping cough), plus Haemophilus influenzae type b.
HepB-Hib Hepatitis B and Haemophilus influenzae type b.

Jet Injectors for Immunization

These needle-free devices were developed in the late 1940s to reduce needle-phobia and pain among diabetic children. High-speed models in use since the 1950s have delivered hundreds of millions of vaccine doses in military settings, epidemics and mass immunization campaigns. The safety of models which use the same nozzle to vaccinate successive patients is in doubt after a hepatitis B outbreak caused by one device in the mid-1980s. A new generation of safer devices using disposable nozzles is in development. They are not entirely pain-free, but reduction of the typical vaccine volume of 0.5ml might help.

Less Painful Vaccine strategies Under Study

Oral and nasal vaccines using live weakened organisms (often genetically engineered): rotavirus, influenza, cholera, salmonella typhi (some can also carry antigens for other diseases like shigella, E. coli, malaria, etc.
Bioengineered plants (e.g. corn, potatoes, tobacco, tomato, alfalfa, lettuce, spinach) or their viruses produce inexpensive, potentially edible antigens. Targeted vaccines: Parvovirus, rabies, cholera, norwalk virus, hepatitis B, malaria, HIV.
Microencapsulation to protect acid-sensitive vaccines from stomach contents.
DNA vaccines administered by blowing tiny DNA-coated gold beads into the skin.
Applying liquid to skin: Cholera toxin as carrier of diphtheria and tetanus antigens through mice skin.

April 1998