Military Jet Injectors: Med-E-Jet

Jet Infectors - Med-E-Jet

Background Info
The Med-E-Jet injector invented by Oscar Banker, an immigrant originally from Armenia. The invention came at the suggestion of Mr. Banker’s wife, who while watching television heard Dr. Robert Hingson discuss his idea of an ideal jet injector. Hingson wished for a multi-use nozzle jet injector that did not rely upon electricity as its energy source. He believed using CO2 as a reliable, effortless energy source would allow a multi-use nozzle jet injector to traverse distant locales (Zsigmond, 2002).

Banker, up to the challenge, attempted to develop such a device. In 1963 and 1964, he filed patents for two similar jet injectors that utilized compressed gas, as Hingson desired (US Patent No. 3292621 A; US Patent No. 3292622 A). However, these devices utilized metapules, which resembled bullets filled with vaccine and restricted the rapidity required for mass vaccinations.

In the mid-1960s, Banker redesigned his invention to replace the need of metapules. The new device utilized a pumping system that sucked liquid medicament from a vaccine vial into a reservoir chamber. When actuated a plunger forced the liquid medicament out of the reservoir, through the nozzle orifice where it was turned into a fine jet stream. He patented this device in May of 1968 (US Patent No. 3518990 A).

The Med-E-Jet was manufactured by the Med-E-Jet Corporation of Cleveland, Ohio. Sometime after the mid-1980s the device was sold to Evans Enterprise of Mayfield Heights, Ohio, who renamed the device as the Med-E-Jet Inoculator. Currently the rights to the device are owned by Donald Kuch of Olmsted Falls, Ohio (Weniger, 2013).

The Med-E-Jet was used within the U.S military and in mass vaccinations campaigns across the globe.

Jet Infectors - Med-E-Jet Injector

Military Usage
Although the Med-E-Jet was not as popular or as widely-used as the Ped-O-Jet, the device was used within the U.S. military between the early 1970s and 1987.

Med-E-Jet Corp tried hard to get a foothold within the Department of Defense (DoD). In 1981 the manufacturer requested the military try its device as shown in the DoD memorandum below. Between August 1981 to October 1981, two Med-E-Jet injectors were used at the Naval Training Center Orlando daily upon recruits. The report states approximately 28,000 shots were administered with these devices.

1981 Med-E-Jet Tested Upon Recruits at Navy Training Center Orlando

In 1987, the Armed Forces Epidemiological Board recommended the discontinuation of Med-E-Jet injectors from the U.S. Military and their removal from the Federal Stock System (Woodward, 1990). This recommendation stemmed after a Med-E-Jet injector was implicated in the transmission of the Hepatitis B Virus to 57 patients within a Los Angeles clinic.

Jet Infectors - AFEB Discontinuation of Med-E-Jet

Research Documented Presence of Blood & Risk of Hepatitis
Numerous laboratory studies have documented the presence of blood when administering jet injections and have implicated Med-E-Jet injectors in the cross-contamination blood and infectious viruses.

  • Dr. J. Black and his colleagues assessed the safety of a Med-E-Jet injector by replicating an experiment from British researcher H.M. Darlow. Within this in vitro test the researchers administered injections into tissue infiltrated with radioactive isotope. After administering an injection into the tissue, the results found no detection of radioactive human serum on the nozzle of the Med-E-Jet. The researchers concluded, “In the demonstrated absence of contamination with blood or tissue fluid, the risk of spreading hepatitis appears remote” (Black et al., 1978). Yet the 1985 outbreak by a Med-E-Jet injector has proven otherwise.
  • In 1985, Peter Brink and his colleagues studied the risk of virus transmission via jet injection. These researchers from the Netherlands assessed the degree of contamination after administering jet injections to mice chronically infected with lactic dehydrogenase (LDV) [better known today as lactate dehydrogenase virus], a highly infectious pathogen. Results found 16 out of 49 (33%) mice became infected with the LDV virus after receiving injections from a Med-E-Jet injector. Most shockingly, researchers observed “post-injection bleeding was relatively uncommon,” occurring in only two out of 49 (4%) of the mice. Assuming the two bleeders were amongst the mice who became infected with LDV, indicates at least 14 out of 16 (88%) of the mice became infected despite the lack of visual bleeding. This is worth repeating, even though there was no visible bleeding during or after the jet injection, transmission of a highly infectious pathogen still occurred. This study demonstrates cross-contamination of a highly infectious virus within microscopic levels via jet injection.

Brink and colleagues concluded transmission occurred when excessive tissue pressure after the delivery/dispersion phase of an injection caused retrograde flow of the liquid medicament that had mixed with skin tissues, blood, and LDV. This retrograde flow is thought to be responsible for carrying the virus in the reverse path of the injection, out of the injection site and contaminating the nozzle orifice of the jet injector. Brink stated until further investigations into the safety of jet injectors are conducted, “it might be justifiable to screen for HBsAg when a patient belongs to a high risk group, or to abandon the jet and give the treatment with individual syringes and needles” (Brink et al., 1985).

Brink and colleagues noted the differentiations between studies accessing the safety of jet injectors. These differences were the cause of conflicting results to the safety of these devices. Several studies—such as, Lipson et al., 1958; Darlow, 1970; Spiess, 1975, and Abb et al., 1981—only delivered intracutaneous jet injections which were shallow injections and elicited less splash back. These studies used an intradermal nozzle, which acted as a spacer to achieve a shallower vaccination within the layers of tissue just under the skin. Therefore, these studies posed a lesser risk and produced negative to minimal contamination than deeper subcutaneous injections, as in Brink’s study, which required direct contact of the jet injector’s nozzle and the vaccinee’s skin. Brink had written, “the investigations cited above were designed to exclude the risk of transmission of virus infection by intracutaneous jet injections. However, subcutaneous jet injections might have a higher risk of contamination, because of the direct contact between skin and nozzle” (Brink et al., 1985).

  • Only months after Brink’s study, the fear of cross-contamination via a jet injector became reality when a Med-E-Jet was implicated in spreading the Hepatitis B Virus amongst patients at a California weight reduction clinic. Amongst those individuals who exclusively received a jet injection, twenty-four percent (57/239) developed an acute Hepatitis B virus infection. (CDC, 1986; Canter et al., 1990). Interestingly, the 22 patients who received injections exclusively by a syringe never acquired the hepatitis B virus (CDC, 1986). The outbreak caused further investigations of the jet injector within the CDC.
  • Laboratory studies by the CDC found hepatitis B contamination could occur when blood or hepatitis B surface antigen (HBsAg) remained within jet injector nozzle orifices. The CDC’s investigation found,

In the first set of experiments (no acetone swabbing), HBsAg was found in 80% of the injection fluid vials and 87% of the swabs from the exterior and interior nozzle surfaces. [That is to say, the internal parts of the Med-E-Jet injector were found to be contaminated with the HBV antigen making the device highly more susceptible to transmitting the virus to the next recipient]. Swabbing the contaminated tip of the Med-E-Jet with a cotton ball moistened in acetone did not significantly reduce the frequency with which HBsAg was found in any of these sites (CDC, 1986).

  • At the request of the World Health Organization, Dr. Peter Hoffman, from the United Kingdom’s Public Health Laboratory Service, created a model to detect whether low volumes of blood were being transferred via jet injectors. Hoffman’s initial investigation in 1997 tested the volume of contamination after a Med-E-Jet injector administered an injection into calves. Assessment of the Med-E-Jet found a 97.4 percent contamination rate above 10 picoliters of blood (Hoffman et al., 2001). These results show gross contamination when using the Med-E-Jet.

In an extended sampling, the Med-E-Jet nozzle was wiped with alcohol between subsequent injections. Results found a lower contamination rate than in the initial series when the nozzle head was not wiped (Hoffman et al., 2001). These results demonstrate when the nozzle is swabbed only superficial contamination is removed and sterilization of the internal fluid pathways is neglected.

  • The WHO panel was shocked with Hoffman’s preliminary findings. WHO noted Hoffman’s preliminary study found “systematic contamination of the fluid path and vaccine reservoir is observed in animal tests of the Med-E-Jet.” The researchers concluded,

A hypothesis has therefore been proposed that contamination of the fluid path occurs along the jet-stream at the end of the shot when pressures in the liquid column at the site of the injection begin to exceed the pressures at the injector head (WHO, 1997).


  • (Abb Deinhardt & Eisenburg, 1981) Abb J, Deinhardt F, Eisenburg J. 1981 The risk of transmission of Hepatitis B virus using jet injection in inoculation. Journal of Infectious Diseases 144: 179.
  • (Black et al., 1978) Black J, Nagle CJ, Strachan CHL. Prophylactic low-dose heparin by jet injection.Br Med J 8 July 1978;2(6130):95.
  • (Brink et al., 1985) Brink PRG, van Loon AM, Trommelen JCM, Gribnau FWJ, Smale-Novakova IRO. Virus transmission by subcutaneous jet injection. J Med Microbiol. December 1985; 20(3): 393-397.
  • (Canter et al., 1990) Canter J, Mackey K, Good LS, Roberto RR, Chin J, Bond WW, Alter MJ, Horan JM. An outbreak of hepatitis B associated with jet injections in a weight reduction clinic. Arch Intern Med. 1990 Sep; 150(9):1923-7.
  • (CDC, 1986) Centers of Disease Control. Epidemiologic Notes and Reports Hepatitis B Associated with Jet Gun Injection — California. MMWR 1986;35(23):373-376.
  • (Darlow, 1970) Darlow HM. Jet vaccination. British Medical Journal 4(734):554, 1970.
  • (Hoffman et al., 2001) Hoffman PN, Abuknesha RA, Andrews NJ, Samuel D, Lloyd JS. A model to assess the infection potential of jet injectors used in mass immunization. Vaccine 19 (2001): 4020-4027.
  • (Lipson et al., 1958) Lipson MJ, Carver DH, Eleff MG, et al. Antibody response to poliomyelitis vaccine administered by jet injection. Am J Public Health 48:599–603, 1958.
  • (Spiess, 1975) Spiess H. Letter: Hepatitis transmission by high pressure injection? Dtsch Med Wochenschr 21 Nov 1975; 100(47): 2465.
  • (US Patent No. 3292621 A) US 3292621 A Banker O. Jet Type Portable Inoculator. Issued 20 December 1966.
  • (US Patent No. 3292622 A) US 3292622 A Banker O. Power Operated Inoculator. Issued 20 December 1966.
  • (US Patent No. 3518990 A) US 3518990 A Banker O. Gun Type Inoculator. Issued 7 July 1970.
  • (Weniger, 2013) Weniger BG. Jet Injection Bibliography. 11 July 2013.
  • (WHO, 1997) World Health Organization. Steering group on the development of jet injection for immunization. May 14, 1997. [draft]
  • (Woodward, 1990) Woodward TE. The Armed Forces Epidemiological Board: Its first fifty years. Center of Excellence in Military Medical Research and Education. 1990.
  • (Zsigmond, 2002) Zsigmond EK. Jet Anesthesia and Jet Local Anesthesia for the 21st Century. Journal of Nat’l Med. Assoc. (2002) 94;11: 1004-06.

© Jet Infectors, 2016 – 2021
Fair Use Notice (17 U.S.C. § 107)

2 thoughts on “Military Jet Injectors: Med-E-Jet

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s