Daily Bulletin


News

  • Written by Vasso Apostolopoulos, Professor of Immunology and Pro Vice-Chancellor, Research Partnerships, Victoria University

Vaccines are traditionally administered with a needle, but this isn’t the only way. For example, certain vaccines can be delivered orally, as a drop on the tongue, or via a jet-like device.

Vaccines that appear particularly suitable to needle-free technology are DNA-based ones, including a COVID-19 vaccine being developed in Australia.

Needle-free vaccines are attractive as they cause less pain and stress to people with needle phobias. But they have other benefits.

Read more: Fear of needles could be a hurdle to COVID-19 vaccination, but here are ways to overcome it

Jet injectors and beyond

The earliest needle-free injection systems date back to 1866 and used jet injectors. These hand-held devices used pressure to penetrate the skin and deliver medicine.

They became increasingly popular around the middle of the 20th century, and were used to deliver vaccines against typhus, polio and smallpox.

A hepatitis B outbreak linked to their use meant they were discontinued in the 1980s. However, research picked up again in the 1990s. Variations included a spring-loaded jet injector (a spring is released to deliver the drug), a battery-powered jet injector, and a gas-powered jet injector.

Jet injection has also been used in dental care to deliver local anaesthetic.

Read more: Australia's just signed up for a shot at 9 COVID-19 vaccines. Here's what to expect

Beyond jet injection, oral vaccines including rotavirus, cholera, polio and typhoid have been around for several decades, and are still used today in various parts of the world. They can come as a liquid or tablet.

More recently, researchers and biotechnology companies have developed vaccines you inhale, such as nasal sprays, as well as skin patches. These are mostly still in clinical testing.

A health worker drops an oral polio vaccine into a child's mouth. Oral vaccines have been around for many years. Shutterstock

DNA-based vaccines and the gene gun

DNA vaccines were a chance discovery as a result of early gene therapy experiments in the 1990s, where injecting DNA into the muscle unexpectedly generated an immune response.

With a DNA vaccine, a small section of the genetic material of the virus is delivered into cells under the skin. These cells then express the DNA as viral proteins. The body recognises these as foreign and stimulates an immune response.

DNA vaccines are simple and cheap to produce in large quantities, and they’re relatively safe as they don’t contain any infective agents, such as live virus.

Read more: From adenoviruses to RNA: the pros and cons of different COVID vaccine technologies

Scientists have explored a number of ways to deliver DNA vaccines, either with a needle or needle free. The needle-free methods include ultrasound (sound waves) and electroporation (electrical pulses) that disrupt cell membranes, allowing DNA into the cells.

The gene gun or “biojector 2000”, a form of jet injector, seems to be the most effective method. This uses pressure to inject DNA into deep layers of the skin. Because it improves the distribution of the vaccine deeper into the injection site, this method uses far less DNA than injection with a needle to generate the same immune response.

But no DNA vaccine has been licensed for use in humans yet. Although needle-free DNA vaccines have shown success in pre-clinical and early clinical trials, DNA vaccines in general are also not as effective in generating immune responses against diseases such as HIV and cancer.

Needle-free COVID-19 contenders

The University of Sydney recently received federal government funding to commence human trials using a “liquid jet” injector to deliver its DNA-vaccine.

Liquid jet injectors use small volumes of liquid forced through a tiny opening (smaller than a human hair). This ultra-fine high pressure stream penetrates the skin where cells then take up the vaccine and stimulate immune cells.

This method was effective in several clinical trials against HIV and is currently used to deliver some influenza vaccines.

A child receives a vaccination with a needle. Needle-free vaccine technologies may be appealing to many people who dislike needles, including children. Shutterstock

Other needle-free COVID-19 vaccines in development include a bandaid-like patch made up of 400 tiny needles, a nasal vaccine, an oral vaccine as a tablet, and a needle-free device that delivers an mRNA vaccine.

Vaccines based on mRNA work in similar ways to DNA vaccines.

Advantages and disadvantages

The advantages of needle-free vaccine technology, specifically jet injectors, include:

  • they may be significantly more acceptable for people afraid of needles, including children

  • there’s no risk of being accidentally injured with a needle

  • they eliminate needle disposal (up to 500 million needles are thrown in landfill every year after vaccinations, and 75 million of these could be infected with blood-borne diseases)

  • they improve vaccine delivery into the skin and use a lower vaccine volume.

Disadvantages include:

  • start-up costs for those using the device, including buying gun devices, and access to gas/air systems to power them

  • staff who administer the vaccine will need special training, and may not feel confident using the technology

  • the equipment needs regular maintenance.

Read more: Eyeing local development: a look at the 3 Australian COVID vaccine candidates to receive a government boost

Authors: Vasso Apostolopoulos, Professor of Immunology and Pro Vice-Chancellor, Research Partnerships, Victoria University

Read more https://theconversation.com/a-covid-19-vaccine-may-come-without-a-needle-the-latest-vaccine-to-protect-without-jabbing-146564

Writers Wanted

How unis can use student housing to solve international student quarantine issues

arrow_forward

The floor is lava: after 1.5 billion years in flux, here's how a new, stronger crust set the stage for life on Earth

arrow_forward

Play Poker Online Here With The Best Odds

arrow_forward

The Conversation
INTERWEBS DIGITAL AGENCY

Politics

Prime Minister Interview with Ben Fordham, 2GB

BEN FORDHAM: Scott Morrison, good morning to you.    PRIME MINISTER: Good morning, Ben. How are you?    FORDHAM: Good. How many days have you got to go?   PRIME MINISTER: I've got another we...

Scott Morrison - avatar Scott Morrison

Prime Minister Interview with Kieran Gilbert, Sky News

KIERAN GILBERT: Kieran Gilbert here with you and the Prime Minister joins me. Prime Minister, thanks so much for your time.  PRIME MINISTER: G'day Kieran.  GILBERT: An assumption a vaccine is ...

Daily Bulletin - avatar Daily Bulletin

Did BLM Really Change the US Police Work?

The Black Lives Matter (BLM) movement has proven that the power of the state rests in the hands of the people it governs. Following the death of 46-year-old black American George Floyd in a case of ...

a Guest Writer - avatar a Guest Writer

Business News

Nisbets’ Collab with The Lobby is Showing the Sexy Side of Hospitality Supply

Hospitality supply services might not immediately make you think ‘sexy’. But when a barkeep in a moodily lit bar holds up the perfectly formed juniper gin balloon or catches the light in the edg...

The Atticism - avatar The Atticism

Buy Instagram Followers And Likes Now

Do you like to buy followers on Instagram? Just give a simple Google search on the internet, and there will be an abounding of seeking outcomes full of businesses offering such services. But, th...

News Co - avatar News Co

Cybersecurity data means nothing to business leaders without context

Top business leaders are starting to realise the widespread impact a cyberattack can have on a business. Unfortunately, according to a study by Forrester Consulting commissioned by Tenable, some...

Scott McKinnel, ANZ Country Manager, Tenable - avatar Scott McKinnel, ANZ Country Manager, Tenable



News Co Media Group

Content & Technology Connecting Global Audiences

More Information - Less Opinion