A Potential Breakthrough: Pfizer’s Ongoing Research on Respiratory Syncytial Virus Vaccines
Image Source: Hailshadow | Istock | Getty Images
Pfizer reported a slight decrease in the efficacy of their respiratory syncytial virus (RSV) vaccine for adults over the age of 60 after 18 months, based on the results of a recent clinical trial.
The trial, conducted by Pfizer in New York, involved over 34,000 older adults over a period of two RSV seasons, equivalent to 24 months. The latest data focuses specifically on participants in the Northern Hemisphere at “mid-season two” in the trial, which is approximately 18 months after vaccination.
After 18 months, the vaccine demonstrated 78.6% effectiveness in preventing more severe lower respiratory tract illness with three or more symptoms. This is a slight decline from the 85.7% efficacy observed at one year. Symptoms included wheezing, shortness of breath, rapid and shallow breathing, and mucus production.
The vaccine showed about 49% effectiveness against the same condition with two or more symptoms after 18 months, indicating a steeper decline compared to the 66.7% efficacy observed at one year, according to Pfizer.
Notably, no adverse events were reported by participants at the 18-month mark, indicating the vaccine’s overall tolerability.
Pfizer has presented these findings to an advisory committee of the Centers for Disease Control and Prevention (CDC) in order to determine the recommended administration schedule for their RSV vaccine, now that it has received approval from the Food and Drug Administration.
This RSV vaccine from Pfizer is the second one to gain approval, following GlaxoSmithKline’s vaccine, which will also present long-term data during the same period.
RSV, known for causing mild cold-like symptoms in most people, can lead to more severe infections in older adults and children. The data suggests that the protection provided by the Pfizer vaccine gradually diminishes over time, similar to what is observed with vaccines for Covid-19 and the flu.
However, the 18-month data indicates that Pfizer’s vaccine still maintains its overall effectiveness against RSV after one year. Further data on the vaccine’s efficacy at 24 months is expected to be released later this year, providing a better understanding of its long-term durability.
According to Annaliesa Anderson, head of Pfizer’s vaccine research and development, the company is “encouraged” by the phase three clinical trial data, particularly regarding the vaccine’s ability to protect against more severe forms of respiratory illness.
Anderson stated, “As with most vaccines, you’re really looking for an impact against more severe disease that causes higher levels of mortality, morbidity, and healthcare-associated contact. To be able to see high efficacy carrying on is very important to us, and we think it’s going to provide people comfort as they take the vaccine.”
Currently, there is no data available on the vaccine’s effectiveness against severe RSV disease, defined as hospitalization, the need for oxygen support, or mechanical ventilation. Pfizer continues to conduct studies in this area, as well as evaluate the vaccine’s efficacy in older adults with weakened immune systems.
According to the CDC, RSV leads to the deaths of 6,000 to 10,000 older adults each year and results in hospitalizations for 60,000 to 160,000 individuals. The risk of hospitalization increases with age, particularly for adults aged 70 and above.
Pfizer estimates that if 50% of individuals aged 60 and older receive their RSV vaccine, it could prevent over 5,000 deaths, 68,000 hospitalizations, 51,000 emergency department visits, and more than 422,000 outpatient visits.
Denial of responsibility! VigourTimes is an automatic aggregator of Global media. In each content, the hyperlink to the primary source is specified. All trademarks belong to their rightful owners, and all materials to their authors. For any complaint, please reach us at – [email protected]. We will take necessary action within 24 hours.
