On Monday, the US Food and Drug Administration approved an antibody injection to protect newborn babies from respiratory syncytial virus, better known as RSV. Nirsevimab, also known by its brand name Beyfortus, is expected to be available this fall, as long as the US Centers for Disease Control and Prevention also gives the green light.
This comes as the FDA has approved and the CDC has recommended that two new RSV vaccines be accessible for adults age 60 and older this fall. The CDC is also weighing an RSV vaccine to be administered to expectant individuals during pregnancy.
Why is it so important to have vaccines and therapeutics that protect against RSV? How effective are the vaccines for older adults? When will they be made available, and who is eligible? Can they be taken along with other vaccines, such as influenza, Covid-19 and shingles? What is the difference between a vaccine and preventive antibody shot? And what’s next in the approval process for the antibody injection and RSV vaccines for newborns?
To help us with these questions, I spoke with CNN Medical Analyst Dr. Leana Wen. Wen is an emergency physician and professor of health policy and management at the George Washington University Milken Institute School of Public Health. She previously served as Baltimore’s health commissioner and is the mother of two young children.
CNN: Why is it so important to have vaccines and therapeutics that protect against RSV?
Dr. Leana Wen: RSV is a very common virus that virtually all children are exposed to by the time they are 2 years old, according to the CDC. While most people who contract RSV will have mild symptoms akin to a cold, some experience very severe symptoms. In the US, around 58,000 to 80,000 children younger than 5 years old are hospitalized because of RSV. Newborns and young babies are especially susceptible. For babies younger than 6 months of age, the rate of hospitalization is as high as 1 to 2 out of every 100 kids infected with RSV.
RSV also poses a major health risk to older adults. As many as 159,000 adults 65 and older are hospitalized each year because of RSV, and around 10,000 to 13,000 die as a result of it.
Preventive measures like handwashing and masking can reduce the risk of contracting RSV, but given how widespread the virus is, it is a major step forward to have vaccines or therapeutics that can reduce the severity of illness, especially in the most vulnerable individuals.
CNN: How effective are the vaccines for older adults? Can anyone take them, or only people over a certain age?
Wen: There are two vaccines, Arexy from GlaxoSmithKline and Abrysvo from Pfizer, that have already received the green light from both the FDA and the CDC. Both are for individuals 60 and older. People below that age are not eligible.
The two vaccines have comparable effectiveness. Arexy’s is 88% effective against RSV that requires medical attention, while Pfizer’s is 85%. They have strong durability. While it’s not known yet whether they will need to be annual vaccines, the vaccines have good durability at least past eight months, so they will last through this year’s RSV season (which, if prior years’ seasons are guides, will be this fall and winter).
CNN: When will these vaccines be made available, and how can older adults access them?
Wen: The CDC has said that the RSV vaccines could be available as early as end of July. Eligible individuals 60 and older should speak with their physicians about the vaccine, and plan to get it where they receive other vaccines, such as pharmacies and doctors’ offices.
CNN: Can the RSV vaccine be given along with other vaccines, like influenza, Covid-19 and shingles?
Wen: Yes, the RSV vaccine can be co-administered with other vaccines. However, I would not advise people to wait. The next Covid-19 booster is not going to be released until end of September. Because the RSV vaccine has strong durability, I think it’s best to get it soon, ahead of the anticipated surge of RSV cases in the fall.
CNN: What is the difference between the vaccine and the preventive antibody injection?
Wen: Vaccines induce the body to make antibodies that can then defend against the virus. The preventive antibody injection gives the antibodies ready-made and doesn’t require the immune system to produce them.
CNN: What’s next in the approval process for the antibody injection and RSV vaccines for newborns?
Wen: The FDA has just approved nirsevimab, the antibody injection that can be given as a single shot to an infant ahead of RSV season. The advisory committee for the CDC will then deliberate and issue recommendations. The group could issue a blanket recommendation for every newborn to receive nirsevimab, or it may make it more limited to, for example, premature babies and those with chronic lung and heart conditions.
According to data from the FDA, nirsevimab was about 70% effective at reducing the risk of requiring a doctor’s visit for RSV and 78% effective at preventing hospitalization due to RSV.
It’s worth noting that another antibody injection, called palivizumab or brand name Synagis, is already approved and available, but it has a limited approval only for those born prematurely who are younger than 6 months. This injection must be administered once a month. Nirsevimab has the benefit of being a single injection per season, and the FDA approval is broader to allow for babies born at full-term to potentially receive it, too.
There is another product under consideration as well. A vaccine from Pfizer, currently called RSVPreF vaccine, has been given approval by the FDA and is pending CDC decision-making. This vaccine is given to pregnant patients, with the expectation that maternal antibodies will help to protect the newborn. The CDC has not issued its final guidance on which group will be recommended to receive this maternal vaccine, and whether nirsevimab is preferred to the maternal vaccine or vice versa.
There is a lot in flux right now when it comes to RSV prevention for newborns, but I think all of it is excellent news. RSV can be a very serious disease, and it’s really good to finally have tools that can prevent severe disease due to RSV, especially for vulnerable individuals.