Breakthrough against RS virus: Two safe, effective vaccines developed

There’s been a breakthrough in the fight against the RS virus - two vaccines have proven to be safe and effective, according to three studies by the Dutch pediatrician infectiologist Louis Bont of UMC Utrecht. One vaccine is administered to pregnant women, the other to newborns, NOS reports.

The RS virus is the second leading cause of infant death worldwide, second only to malaria. Although it is rare for a child to die of the virus in the Netherlands, about 150 to 200 babies end up in ICU due to RSV per year. Among healthy infants, one in 56 is hospitalized due to an RS infection.

Pfizer developed the first vaccine. The pregnant woman is vaccinated, and the antibodies she produces are then transferred to the baby through the placenta. Trials involving 7,400 women and their babies showed that it protects babies well against the RS virus in their first three vulnerable months.

“I expect that this vaccine will prevent a considerable proportion of hospitalizations. Every year about 2,000 children with RSV end up in the hospital, and I think we can prevent between 1,000 and 1,500 of those admissions. That’s really an unbelievable amount,” Bont said. According to UMC Utrecht, the European Union will likely register this vaccine next year. It can also protect older people with poor health who get flu-like symptoms and respiratory infections from RSV.

The second vaccine, made by AstraZeneca and Sanofi, is for newborns. The EU already registered this vaccine late last year. The antibody in this vaccine targets a protein on the virus's surface. Bont’s research showed that the vaccine is safe and protects against RSV for extended periods.

According to Bont, both vaccines are safe and have no known severe side effects. “Every vaccine has side effects - think of redness at the injection site - but with the pregnancy vaccine, you can really speak of safe immunization. And the baby vaccine is even safer.” The vaccines offer 80 percent protection, so people will still get the virus but with less severe symptoms. “This is the solution for that first year of life when RSV can be so dangerous,” Bont said.

The Bill & Melinda Gates Foundation bought the rights to the Pfizer vaccine and wants to produce it for and in developing countries. Bont is very excited about that. “In this way, you can really prevent a lot of mortality in the world. So many children are dying,” Bont said. “Normally, Pfizer has little interest in sending a drug to developing countries, so it ends up in countries where it makes much less difference. Where the vaccine is less needed.”