Protecting Infants, Young Children by Vaccinating Teens and Adults

The value and need for pediatric vaccines is on display and abundently clear with what is being experienced right now in parts of the United States.

Hospitals are filling up with cases of pediatric RSV. Some hospitals are overcapacity and either having families wait long hours for a bed to become available or hospitals are sending families to other healthcare facilities miles away.

At the moment there are no FDA approved RSV vaccines available for any population, and as we have entered into the seasonal virus season in the northern hemisphere, the return of additional respiratory infections will begin to surface.

For example, pertussis or whooping cough continues to be a burdensome challenge. There is an estimated 24.1 million cases of pertussis and about 160,700 deaths worldwide per year, according to the Centers for Disease Control and Prevention. And vaccine coverage for the youngest patients can be somewhat limited. According to Dynavax Technologies Chief Medical Officer Robert Janssen, MD, as many as 17 million infants were not given the Diphtheria Tetanus and Pertussis (Dtap) vaccine and another 5.6 million were only partially vaccinated.

In addition, pertussis is a highly contagious virus that can be spread from adults and teens to the youngest populations.

“It’s critical that infants get vaccinated as it’s critical that adolescents and adults get vaccinated too,” Janssen said. He mentions the need for the latter groups to get a vaccine because of outbreaks that occur every 3-4 years. He says that approximately 60% of cases in the United States occur in teens and adults, thus making vulnerable family members such as infants and young children at risk for pertussis.

Right now public health officials and biopharmaceutical companies are looking for ways to protect infants and young children from respiratory infections and one strategy is to vaccinate teens and adults to avoid transmitting viruses to the former, vulnerable populations.

For example, there are ongoing studies for an investigational RSV vaccine being administered to expecting mothers.

Dynavax is a biopharmaceutical company exploring the utility of vaccines in adults and teens for not only protection for the person vaccinated, but vulnerable populations such as infants or expecting mothers. The idea here is for the mother to provide antibodies that get passed along to their babies.

Dynavax has developed its diphtheria tetanus and pertussis booster vaccine (Tdap-1018 CpG Adjuvanted) and released its results during the recent ID Week. The company's results were presented at the conference as a poster titled, “Safety, Tolerability, and Pertussis Immunogenicity Findings From a Randomized, Participant-Blinded, Active-Controlled, Dose-Escalating, Phase 1 Trial of a Tetanus/Diphtheria/Pertussis Booster Vaccine (Tdap-1018 CpG Adjuvanted) Compared With Boostrix in Healthy Adults Aged 18 to 22 Years.”

In this randomized, controlled participant-blinded, study, adults aged 18 to 22 years received 1 booster dose Tdap-1018 (with same Tdap composition as in Boostrix and escalating CpG 1018 dose of 1500 µg and 3000 µg) or Boostrix on Day 1. “Pertussis immunogenicity evaluations assessed booster response rates (BRRs) for anti-pertussis toxin (anti-PT), anti-filamentous hemagglutinin (anti-FHA), and anti-pertactin (anti-PRN) antibodies, and systems serology at Week 4 post-vaccination,” the investigators wrote. “Safety and tolerability were assessed for solicited local and systemic post-injection reactions for 7 days and unsolicited adverse events for 12 weeks after vaccination.”

“In this phase 1 trial, both dose levels of Tdap-1018 were generally well tolerated. Tdap-1018 3000 µg induced statistically significantly higher BRRs than Boostrix for anti-PT and anti-PRN, and a similar response for anti-FHA antibodies,” the investigators wrote.

Contagion spoke to Janssen about their booster vaccine including its study results, next steps, and how it could be utilized in the market if approved.