Miller Fisher Syndrome

Respiratory syncytial virus had stymied vaccine research efforts for decades. Now there are two vaccines approved for the pathogen. The FDA on Wednesday approved Pfizer’s RSV vaccine, which carries the brand name Abrysvo. The regulatory decision follows the approval of GSK’s RSV shot, Arexvy, in early May. The approvals of both vaccines cover the prevention of lower respiratory tract disease caused by RSV in those age 60 and older. RSV typically leads to symptoms resembling those of the common cold in healthy people. But in infants, the elderly, and those with weakened immune systems, the pathogen can cause a serious and potentially deadly infection. The Centers for Disease Control and Prevention estimates that each year, RSV infection results in between 60,000 and 160,000 hospitalizations in those 65 and older and as many as 10,000 deaths in that age group. The approved RSV vaccines from Pfizer and GSK as well as others in development build on National Institutes of Health research regarding a key protein that the virus uses to enter cells. NIH scientists found that antibodies to a prefusion version of this protein are highly effective at preventing infection. The antigens in Abrysvo are two version of pre-fusion F (preF) proteins engineered to elicit an immune response that protects against the RSV A and B strains. The Pfizer vaccine does not include an adjuvant, an ingredient that boosts the immune response. FDA approval of Abrysvo is based on the results so far from a placebo-controlled Phase 3 clinical trial that enrolled about 37,000 people. On the main goal of preventing severe lower respiratory tract infection, interim results showed vaccine efficacy of 85.7%. Results from the clinical trial were published in April in the New England Journal of Medicine. The Phase 3 study spans two RSV seasons. Pfizer said efficacy data are still being collected from the second RSV season. The Pfizer RSV vaccine was well tolerated by study participants. The most common adverse effects reported in the study included fatigue, headache, injection site pain, and muscle pain. Three patients in the Abrysvo arm experienced serious adverse effects that were deemed possibly related to the vaccine, according to the prescribing information. One was Guillain-Barré syndrome, in which an immune response damages nerve cells. The other was Miller Fisher syndrome, a nerve disease related to Guillain-Barré. A third participant experienced hypersensitivity. Guillain-Barré was observed in a study evaluating GSK’s RSV shot in older adults. The FDA’s approval of that vaccine includes a post-marketing requirement that the company conduct additional testing to assess the risk of Guillain-Barré as well as acute disseminated encephalomyelitis, a type of brain and spinal cord inflammation. The approval of Pfizer’s vaccine carries no such post-marketing requirements. “A vaccine to help prevent RSV had been an elusive public health goal for more than half a century,” Annaliesa Anderson, senior vice president and chief scientific officer, vaccine research and development, Pfizer, said in a prepared statement. “Today’s approval is a monumental step forward in delivering on Pfizer’s commitment to help alleviate the significant burden of RSV in higher-risk populations, which includes older adults.” The next step for both the Pfizer and GSK RSV vaccines is a June 21 meeting of the CDC’s Advisory Committee on Immunization Practices. The body will discuss the vaccines and make recommendations on their use in older adults. Like GSK, Pfizer anticipates its vaccine will become available in the third quarter in advance of the RSV season. By this coming fall, the FDA might already have a decision on the use of the Pfizer RSV vaccine in pregnant women to offer protection to infants. Sanofi and AstraZeneca aim to protect infants with an antibody drug. The product, approved last year in Europe where it is branded as Beyfortus, is currently under FDA review. Meanwhile, an RSV vaccine from Moderna posted positive Phase 3 data and the company has said it expects to seek regulatory approval in the first half of this year. Public domain image by the CDC

THURSDAY, June 1, 2023 -- Older adults may have a second vaccine option for RSV following the U.S. Food and Drug Administration's approval of a Pfizer vaccine on Wednesday. The other shot for adults 60 and up is made by GSK. It was approved May 3. Both should be available by fall, before the seasonal spread of respiratory syncytial virus (RSV), T he New York Times reported. The Pfizer vaccine, known as Abrysvo , has effectiveness of nearly 67% when a patient has two symptoms of RSV, such as a sore throat and cough. It's 86% effective when three or more symptoms surface. Its GSK competitor — named Arexvy — was about 83% effective against severe RSV, the Times reported. The study on the Pfizer vaccine did include a concern about autoimmune syndromes. One patient among the 34,000 who received the vaccine in the study developed a life-threatening case of Guillain-Barré syndrome a week after receiving the shot. Another developed Miller Fisher syndrome, which is a subtype of that condition. That means the incidence rate for these syndromes is 1 in 9,000, higher than the 1 in 100,000 seen in the general population. FDA advisors voted 7 to 4 in favor of the vaccine’s safety and efficacy. It had voted 10 to 2 for the GSK vaccine, which was linked to similar cases. Advisers for the U.S. Centers for Disease Control and Prevention will meet this month to talk about their recommendations for health care providers. They have suggested that the vaccines may be recommended for those aged 65 and older, according to the Times . The vaccines come after a winter season in which COVID-19, the flu and RSV all spread. While RSV infection is generally mild and cold-like in healthy people, it can be fatal in infants and the elderly. In the United States, about 60,000 adults aged 65 and up are hospitalized with RSV, and 6,000 to 10,000 die each year, the FDA estimated. To prevent one of these deaths, about 21,000 to 25,000 older adults would have to be vaccinated against RSV, depending on the vaccine. Seniors on Medicaid and Medicare will not have a co-pay for a vaccine deemed medically necessary, a Pfizer spokeswoman said. Sources The New York Times Posted June 2023

THURSDAY, June 1, 2023 -- Older adults have a second vaccine option for respiratory syncytial virus (RSV) following the U.S. Food and Drug Administration approval of a Pfizer vaccine on Wednesday. The other shot for adults 60 years and older is made by GlaxoSmithKline. It was approved May 3. Both should be available by fall, before the seasonal spread of RSV, The New York Times reported. The Pfizer vaccine, known as Abrysvo, has effectiveness of nearly 67 percent when a patient has two symptoms of RSV, such as a sore throat and cough. It is 86 percent effective when three or more symptoms surface. Its GSK competitor -- named Arexvy -- was about 83 percent effective against severe RSV, The Times reported. The study on the Pfizer vaccine did include a concern about autoimmune syndromes. One patient among the 34,000 who received the vaccine in the study developed a life-threatening case of Guillain-Barré syndrome a week after receiving the shot. Another developed Miller Fisher syndrome, a subtype of Guillain-Barré. That means the incidence rate for these syndromes is one in 9,000, higher than the one in 100,000 seen in the general population. FDA advisers voted 7 to 4 in favor of the vaccine's safety and efficacy. The panel had voted 10 to 2 for the GSK vaccine, which was linked to similar cases. Advisers for the U.S. Centers for Disease Control and Prevention will meet this month to talk about their recommendations for health care providers. They have suggested that the vaccines may be recommended for those aged 65 years and older, according to The Times . The New York Times Article More Information Posted June 2023