A coronavirus vaccine may arrive next year. 'Herd immunity' will take longer.
Anthony Fauci, the foremost infectious diseases expert in the U.S., has said a coronavirus vaccine could be available within 12 to 18 months. His timeline isn't just ambitious; it's unprecedented speed for a vaccine, which typically take many years of testing to make it to market.
The challenges are many. Any vaccine available at such speed likely won't have data definitively proving it is safe and effective at preventing infection, forcing regulators to make a difficult choice. A vaccine for the new coronavirus, currently confirmed to have infected more than 3.4 million people worldwide through Monday, would have to be manufactured for the masses far faster, and at wider scale, than ever before. And there's no guarantee that a vaccine could provide the broad protection necessary to curb the coronavirus pandemic.
"I think the 12 to 18 months that has been mentioned is optimistic," Walter Orenstein, an Emory University medical school professor and associate director of the Emory Vaccines Center, said in an interview with BioPharma Dive. "It's possible if everything goes right, but with most vaccines it takes longer than that."
Raising the stakes on clinical development is the Trump administration's "Operation Warp Speed," which aims not only to have an approved vaccine, but also enough doses for every American by January. The president is asking the sector to compress a development cycle that can sometimes take decades into just 12 months — a feat that will require Americans to accept higher-than-usual safety risks along with the possibility the first vaccine they receive won't work that well.
Herd immunity, as it is known, occurs when enough people are immune to an infectious disease to prevent its spread.
Achieving herd immunity to SARS-CoV2 infection may be the biggest step toward returning social and economic activities to normal, as social distancing rules may persist while the virus circulates and people continue to get sick and die. Economic forecasters' assumptions about a future rebound rely on such an outcome.
Typically, herd immunity isn't achieved in a year or two. Vaccines can take up to a decade or more to win approval based on their ability to prevent disease in tens of thousands of people. For example, GlaxoSmithKline's vaccine Shingrix won approval on the basis of results in nearly 33,000 patients followed for four years, in which the vaccine reduced shingles cases by around 97% when compared with placebo.
Given the urgency of the coronavirus pandemic, however, the Food and Drug Administration is likely to accelerate the standard process and grant a vaccine an emergency use authorization — a limited declaration that, while not equivalent to a standard drug approval, makes a medicine available during public health emergencies. That decision may come after a vaccine has shown only whether it can induce an immune response in a comparatively small group of people, not that it can safely prevent infections.