Before a drop of an oral immunization reaches a newborn’s mouth or a syringe delivers a first shot, vaccines have cleared a multitude of hurdles, each carefully designed to ensure that they are safe and effective.
“It takes a village to raise a child,” the saying goes, and one of the first instances of collective care a child receives is immunization. Bringing a vaccine through research and into the clinic or field takes a veritable village of scientists, experts, and ethicists, and a rigorous process that ensures they collaborate at the highest standards.
My role as director of the Vaccine Development Program at PATH, and a long career in vaccine research and development, have afforded me valuable insight on the need for vaccines throughout the world and the commitment of scientists in making sure vaccines safely protect our children.
From the initial stages of early research and clinical development through regulatory approval and use, vaccines are painstakingly evaluated for safety and efficacy. By the time a physician prepares an injection and administers it to stimulate a child’s immune system, the vaccine contained within has been carefully studied in the laboratory and through several phases of clinical trials.
Each phase builds on the information received from the previous one, and if safety is not assured at any point, the vaccine candidate simply does not advance.
On the journey to impact: the role of independent reviewers
A trial’s researchers aren’t the only ones to evaluate vaccine safety: expert, independent advisors make pivotal contributions throughout.
Ethical committees, independent safety review boards, and regulatory agencies—among these the US Food and Drug Administration and its counterparts in other countries—must approve a trial’s design before it commences.
Each trial incorporates multiple levels of oversight to ensure the safety of its subjects. These groups join safety monitors and local community advisors in routinely checking standards, ensuring informed consent, and reviewing data collection. They evaluate all reported adverse events, both expected and unexpected, their severity and frequency, and whether such events call for halting the trial.
Defining impact: affordable, safe, and effective for all children
From this village of scientists and experts, ultimately we derive our intended impact—affordable, safe and effective vaccines for all children around the world, and particularly those in villages themselves: rural communities where the luxuries of our everyday lives aren’t available to help keep kids healthy.
In communities where safe drinking water, access to routine health care, or appropriate nutrition are beyond reach, immunization may be the only health intervention that is both affordable and effective. Even today, children are suffering needlessly from diseases that we know vaccines can prevent. With infectious diseases like polio, measles, and Haemophilus influenzae type b all but eradicated in the US, many have forgotten how threatening and devastating they can be.
A mistaken interpretation of the risks and benefits of vaccination may lead some parents to incorrectly conclude that the vaccines themselves pose a greater risk than the diseases they prevent. When vaccines spare us from fear of disease—a reassurance that can too easily lead to complacency—lack of attention to vaccination can allow the diseases to return, causing needless illness and death.
Value of vaccines: a global view
Where pneumonia, diarrhea, measles, influenza, and other vaccine-preventable diseases are still viewed as a common, lethal threats, the promise of vaccines takes on vital value and priority among families.
When our team and partners select clinics and communities to participate in large vaccine field trials—culminating steps in the long process to demonstrate safety and efficacy—we find that parents are eager to help investigate a vaccine that could literally mean the difference between life and death.
And for those who graciously participate in vaccine trials, researchers provide comprehensive information when requesting their consent for enrollment and sharing background about the disease, the vaccine candidate and manufacturer, risks, benefits, and how the clinical trial will be conducted.
The science continues
After clinical trials, once a vaccine has demonstrated appropriate safety and significant potential for preventing disease, after it is licensed and put into practice, the science continues.
Effectiveness studies allow us to see direct real-world impact as well as the value of herd immunity, which emphasizes the urgency to immunize children eligible for vaccination to better protect those who cannot be vaccinated because they are too young or their immune systems are compromised.
Routine surveillance shows us how well vaccines perform but also how rapidly risk can rise when families forego immunization.
Manufacturers and public health authorities monitor the experience of many thousands of children over many years to identify adverse events that are potentially related to vaccination but so rare that they may never appear in clinical trials. Ongoing evaluations of these very rare adverse events occurring in both vaccinated and unvaccinated populations, together with other data collected in post-marketing studies, enable us to further define vaccines’ real-world risk/benefit ratio.
Clinical studies are crucial steps along the journey to make sure that every child is protected from vaccine-preventable diseases. Careful study allows PATH and our partners to ensure that new vaccines are safe and effective and ultimately close gaps in access to lifesaving immunizations.
By also strengthening health systems, accelerating research and development, and creating innovative technology solutions, PATH is working to make safe and effective vaccines affordable and available to all families.
This post is part of Mapping the Journey, a multi-part series which explores how PATH turns ideas into solutions that bring equity, dignity, and health to women, children, and families worldwide.
- John Donnelly was formerly the director of the Vaccine Development program at PATH.