FDA approves GSK shot for older adults

The Food and Drug Administration on Wednesday approved an RSV vaccine manufactured by GlaxoSmithKline for use in adults age 60 and older.

The approval, the first globally by a regulatory body for an RSV vaccine, is a decisive victory for GSK in a race against drugmakers Pfizer and Moderna to bring to market a shot that targets respiratory syncytial virus.

Shares in GSK rose almost 2% on Wednesday after the approval.

GSK’s chief scientific officer Tony Wood said in a statement that the decision “marks a turning point” in the company’s efforts to reduce the “significant burden” of RSV.

The company will now focus on ensuring eligible older adults in the United States can access the vaccine “as quickly as possible,” he said. GSK will also work towards regulatory review and approval of the shot in other countries.

London-based GSK said during a results presentation last week that it has “millions” of doses of the RSV vaccine ready to ship.

The company plans to meet in June with the federal Centers for Disease Control and Prevention’s vaccine advisory committee to hash out potential vaccination plans for the United States, according to that presentation.

GSK’s shot is also approaching approval in the EU. Last week, the European Medicines Agency recommended that the company’s vaccine be approved by the EU for older adults.

The shot would help countries combat the next RSV season in the fall.

The United States suffered an unusually severe RSV season last year.

Cases of the virus in children and older adults overwhelmed hospitals across the country, largely because the public stopped practicing Covid pandemic health measures that had helped keep the spread of RSV low.

RSV usually causes mild, cold-like symptoms. But each year, the virus kills 6,000 to 10,000 elderly people and a few hundred children under the age of 5, according to the CDC.

The FDA said the approval of GSK’s vaccine was based on data from a phase three study in older adults.

In March, an independent panel of advisors to the FDA recommended the shot based on those trial results, which found the shot nearly 83% effective in preventing lower respiratory illnesses caused by RSV. Illness was defined as two or more symptoms including shortness of breath, wheezing, cough, increased mucus production, crackles, low oxygen saturation or need for oxygen supplementation.

The independent panel unanimously said that the efficacy data on GSK’s vaccine was sufficient.

But the advisers also flagged potential safety concerns over a nervous system disorder, Guillain-Barre syndrome, that may be linked to the shot.

A 78-year-old woman in Japan was diagnosed with Guillain-Barre syndrome nine days after receiving GSK’s vaccine, according to an FDA document. She was hospitalized for six months before being released.

The document said the woman was the only case of Guillain-Barre syndrome out of the more than 12,000 people who received the shot.

GSK said in February that there is insufficient evidence to confirm that the woman developed Guillain-Barre as a result of GSK’s shot.

But the FDA said at the time that it considers the case to be related to GSK’s vaccine.

On Wednesday, the agency said it will require GSK to conduct a study to further assess the risk of Guillain-Barre syndrome and another side effect observed in a clinical trial that co-administered the RSV shot with a flu vaccine.

Guillain-Barre syndrome is a rare disorder in which the immune system attacks its own nerves, causing muscle weakness and sometimes paralysis. Most people recover completely from the disorder, but some cases can be fatal or have lasting effects.

The incidence of Guillain-Barre syndrome is typically one to two cases per 100,000 people each year in the United States, according to the National Organization for Rare Disorders.

The FDA flagged the disorder as a potential safety concern with Pfizer’s RSV vaccine for older adults.

Two people developed Guillain-Barre syndrome after receiving Pfizer’s shot in a late-stage clinical trial involving more than 20,000 vaccine recipients.

Pfizer said in February that it would conduct a safety study to further evaluate Guillain-Barre syndrome if the FDA approves the vaccine.

The pharmaceutical company hopes to win that approval later this month.

No cases of Guillain-Barre syndrome were identified during a clinical trial of Moderna’s RSV vaccine.

Moderna plans to submit an application for FDA approval during the first half of this year.