Today, immunization programs are transforming our world, having eradicated smallpox and significantly reduced the impact of many other diseases like polio, measles, and meningitis. Vaccination prevents around five million deaths every year, and has helped to halve child mortality over the past 25 years. However, infectious diseases still kill millions and children are particularly vulnerable. Among children under five, pneumonia is one of the biggest killers, while measles remains among the deadliest diseases worldwide. And infectious diseases do not respect borders: this year, Texas, USA suffered an alarming outbreak of measles, mostly among children and almost entirely among the unvaccinated.

Vaccination protects children and stops the spread of infectious diseases: The more people that are vaccinated, the safer the world becomes. Following the lead of national governments, organizations such as the WHO, UNICEF, and Gavi, the Vaccine Alliance support immunization programs reaching millions of children in some of the most hard to reach places. But recently, vaccination rates have stagnated: Coverage for the vaccine that protects against diphtheria, tetanus, and pertussis – the measure of basic childhood immunization- stalled at around 84 percent in 2023. The ideal is to make vaccines available to everyone, and especially to the most vulnerable children in regions where infectious diseases are most prevalent. And as Jenner’s work drove forward the development of the first vaccines, pioneering new innovations are now driving ever more effective, efficient, and equitable access to vaccination.

Remarkably, protection against some diseases can now begin before birth by vaccinating pregnant mothers— the vaccine stimulates an immune response in the pregnant mother, who passes protective antibodies to the baby, protecting them from the moment they are born. Such ‘maternal vaccination’ is widely used to protect newborn babies from tetanus and flu, and new developments have also made it possible for respiratory syncytial virus (RSV). Common among infants, RSV causes breathing difficulties and is the most common cause of pneumonia in infants younger than six months old. After decades of research, a new maternal vaccine for RSV has been developed and will be available to lower-income countries where it is most needed- helping to reduce the 3.6 million hospitalizations and 100,000 deaths in children under five caused by RSV.

Thanks to pioneering scientific research, vaccines are now available for more than 30 life-threatening diseases and infections. To maximize the opportunity this brings, it is key to work with countries and partners to efficiently expand global access to these life-saving tools. The new hexavalent vaccine plays a crucial role in this. It combines protection against six deadly diseases in a single vaccine, protecting a child against diphtheria, tetanus, pertussis, Haemophilus influenzae B, hepatitis B, and polio. Reducing the number of injections makes it easier for children to get their full slate of immunizations and reduces burden on caregivers, healthcare workers, and overstretched healthcare systems.

Another way researchers are working to expand access is by exploring a simpler way of administering vaccines using microneedle array patches (MAPs). About the size of a small bandage, a single-use MAP is applied to the skin where many microscopic needles deliver the vaccine into the body. It only takes minutes, and unlike traditional injections, administering a MAP may not require a highly trained health worker—it could be given by volunteers. Early trials in The Gambia have shown these patches can deliver the measles-rubella vaccines to adults, toddlers, and infants as safely and effectively as syringes.

Key to ensuring a vaccine’s efficacy is the cold chain, a network of refrigerators, freezers, and cold storage boxes that keep vaccines at the right temperature as they travel. With vaccines highly sensitive to temperature, the value of a little sticky label called a VVM cannot be overstated. VVMs, short for vaccine vial monitors, are heat-sensitive stickers that change color with cumulative exposure to heat. They enable health professionals to see at a glance when a vaccine should not be used.

But when a vaccine’s end destination lacks reliable electricity for refrigeration, the Solar Direct-Drive (SDD) refrigerator is rising to the challenge. It not only harnesses solar energy to keep vaccines at the right temperature but also stores excess energy to keep running through sunless days. For many communities they can be transformational: in Kenya’s Makueni County, the installation of an SDD refrigerator doubled the vaccination rate for children.

In the garden of Edward Jenner’s home, now a museum, is an eccentric-looking thatched summerhouse that he named his Temple of Vaccinia. Here, Jenner worked tirelessly to provide free vaccinations. It is fitting that the father of immunization never sought to profit from his efforts and was committed to equitable vaccination, because that’s what it takes to prevent infectious diseases from spreading. Through the collaborative efforts of health workers, governments, and organizations, adequately funding critical immunization programs, and harnessing the power of science and innovation, progress is possible—bringing the world closer to ending preventable child deaths.

Source: National Geographic