CAMBRIDGE, Mass. — Scientists have developed a 3D-printed microneedle vaccine patch patients can apply to their skin, offering a pain-free alternative to traditional injections. Researchers from the Massachusetts Institute of Technology (MIT) say you can store these patches at room temperature for months, making them ideal for large-scale shipments to developing nations.
“We could someday have on-demand vaccine production. If, for example, there was an Ebola outbreak in a particular region, one could ship a few of these printers there and vaccinate the people in that location,” says study co-author Dr. Ana Jaklenec in a media release, who adds this technique has the potential to revolutionize immunization programs.
A vaccine “ink” is injected into molds by a robotic arm and then drawn to the tips using a vacuum chamber. The resulting patches, about the size of a thumbnail, contain hundreds of microneedles that enable the vaccine to dissolve. Experiments found these patches to be as effective at protecting mice against COVID-19 as traditional injections.
Most vaccines require refrigeration, making stockpiling and distribution difficult. They also need syringes, needles, and trained healthcare professionals for administration. Similar patches are now being developed to combat polio, measles, and rubella. The needles’ tips dissolve under the skin, releasing the vaccine.
“When COVID-19 started, concerns about vaccine stability and vaccine access motivated us to try to incorporate RNA vaccines into microneedle patches,” explains lead author Dr. John Daristotle.
The ink consists of RNA vaccine molecules encapsulated in lipid nanoparticles, which help maintain their stability for extended periods. After filling the molds, they take a day or two to dry. The current prototype can produce 100 patches in 48 hours, with the hope that future versions will have higher capacities.
Scroll down to read 5 facts about modern-day vaccines
Scientists could produce ‘on-demand’ vaccines
The researchers first created an ink containing RNA that encodes luciferase, a fluorescent protein. They applied the resulting microneedle patches to mice after storing them at either four degrees Celsius or 25 degrees Celsius (room temperature) for up to six months. They also stored one batch of particles at 37 degrees Celsius for one month. Under all storage conditions, the patches induced a strong fluorescent response when applied to mice. In contrast, the fluorescent response produced by a traditional intramuscular injection of the fluorescent-protein-encoding RNA declined with longer storage times at room temperature.
The researchers then tested their COVID-19 microneedle vaccine. They vaccinated mice with two doses of the vaccine, four weeks apart, and measured their antibody response to the virus. Mice vaccinated with the microneedle patch had a similar response to those vaccinated with a traditional, injected RNA vaccine. The researchers also observed the same robust antibody response when they vaccinated mice with microneedle patches stored at room temperature for up to three months.
“This work is particularly exciting as it realizes the ability to produce vaccines on demand,” says Joseph DeSimone, a professor of translational medicine and chemical engineering at Stanford University, who did not take part in this research. “With the possibility of scaling up vaccine manufacturing and improved stability at higher temperatures, mobile vaccine printers can facilitate widespread access to RNA vaccines.”
The researchers plan to adapt the process to produce other types of vaccines, including those made from proteins or inactivated viruses.
“The ink composition was key in stabilizing mRNA vaccines, but the ink can contain various types of vaccines or even drugs, allowing for flexibility and modularity in what can be delivered using this microneedle platform,” Jaklenec concludes.
The new study is published in the journal Nature Biotechnology.
5 facts about vaccines from StudyFinds’ Dr. Faith Coleman:
1. If a child is mildly ill, immunization can proceed using the recommended schedule for healthy children.
Since a mild illness does not affect how well the body responds to a vaccine, your child can still be vaccinated if he or she has:
- A low grade fever
- A cold, runny nose, or cough
- An ear infection (otitis media)
- Mild diarrhea
Doctors at leading health organizations, like the American Academy of Pediatrics and the American Academy of Family Practice, recommend that children with mild illnesses receive vaccinations on schedule. There is no health benefit to waiting to immunize your child if he or she has a mild illness. Children need to get their vaccines on time so that they are protected against serious, even life-threatening diseases.
2. Pregnant women should receive the flu vaccine during pregnancy
Influenza (flu) is more likely to cause illness that results in hospitalization in pregnant people than in women of the same age who are not pregnant. Flu can even be harmful for a developing baby. Fever, a common flu symptom, has an association with neural tube (spine and brain) defects and other poor outcomes for a developing baby.
Getting vaccinated during pregnancy also protects a baby from flu during the first several months after birth, from antibodies the mother passed on during the pregnancy. Antibodies are also passed on in breast milk, protecting the breastfed infant.
3. COVID-19 vaccinations begin at 6 months of age.
The Centers for Disease Control and Prevention (CDC) recommend COVID-19 vaccines for everyone ages six months and older, and COVID-19 boosters for everyone five years and older. Ongoing safety monitoring ensures that the vaccination is safe for children and teens. The known risks and potential severe complications of the disease outweigh the potential risks of having a rare adverse reaction to vaccination.
4. Vaccines in which the infectious agent is alive and weakened produce the strongest immune response
There are several different types of vaccines:
- Live attenuated vaccines, in which the infectious agent is alive but weakened, mimic natural infection, producing a strong immune response.
- Subunit vaccines, which are generated from parts of the infectious agent (often surface proteins) generally produce long-lasting immune protection.
- DNA vaccines contain one or more segments of the infectious agent’s genetic material. Cells use the genetic information to produce immune-stimulating proteins. These vaccines are relatively inexpensive and simple to produce. They are associated with long-lasting immunity.
- RNA vaccines, like DNA vaccines, contain segments of genetic material. They are also less expensive than other types of vaccines and easier to produce. It was RNA vaccines that were developed quickly and used to help stop the spread of COVID-19, or limit the severity of illness, during the global pandemic.
5. No vaccines have ever had an association with autism
Autism spectrum disorder (ASD) is a developmental disability that causes significant communication, social, and behavioral challenges. The CDC’s Autism and Developmental Disabilities Monitoring Network finds that about one in 44 children have ASD across the United States.
Some people have had concerns that ASD might have a link to childhood vaccines, but hundreds of studies have shown that there is no link between receiving vaccines and developing ASD.
Your best source of information for parents on vaccines from birth through 18 years is the CDC website: Vaccines for Your Children
You might also be interested in:
- Fact or Fiction: 10 Common Beliefs About Vaccines Explained
- Vaccines replacing needles with puffs of air could feel like painless Nerf darts
South West News Service writer Mark Waghorn contributed to this report.