Scientific doubt tempers COVID-19 vaccine optimism
US government and industry projections that a COVID-19 vaccine will be ready by this fall or even January would take compressing what usually takes at least a decade into months, with little room for error or safety surprises.
“If all the cards fall into the right place and all the stars are aligned, you definitely could get a vaccine by December or January,” Anthony Fauci, MD, director of the National Institute of Allergy and Infectious Diseases, said last week.
But Fauci said a more realistic timeline is still 12 to 18 months, and experts interviewed by Medscape Medical News agree. They say that although recent developments are encouraging, history and scientific reason say the day when a COVID-19 vaccine is widely available will not come this year and may not come by the end of 2021.
The encouraging signals come primarily from two recent announcements: the $1.2 billion United States backing last week of one vaccine platform and the announcement on May 18 that the first human trials of another have produced some positive phase 1 results.
Recent developments
On May 21, the US Department of Health and Human Services (HHS) under “Operation Warp Speed” announced that the US will give AstraZeneca $1.2 billion “to make available at least 300 million doses of a coronavirus vaccine called AZD1222, with the first doses delivered as early as October 2020.”
On May 18, the Massachusetts-based biotechnology company Moderna announced that phase 1 clinical results showed that its vaccine candidate, which uses a new messenger RNA (mRNA) technology, appeared safe. Eight participants in the human trials were able to produce neutralizing antibodies that researchers believe are important in developing protection from the virus.
Moderna Chief Medical Officer Tal Zaks, MD, PhD told CNN that if the vaccine candidate does well in phase 2, “it could be ready by January 2021.”
The two candidates are among 10 in clinical trials for the SARS-CoV-2 virus, according to the World Health Organization (WHO). The AstraZeneca/ AZD1222 candidate (also called ChAdOx1 nCoV-19, in collaboration with the University of Oxford) has entered phase 2/3.
Moderna’s candidate and another being developed in Beijing, China, are in phase 2, WHO reports. As of yesterday, 115 other candidates are in preclinical evaluation.
Maria Elena Bottazzi, PhD, associate dean of the National School of Tropical Medicine at Baylor College of Medicine in Houston, Texas, told Medscape Medical News it’s important to realize that, in the case of the $1.2 billion US investment, “what they’re talking about is manufacturing.”
The idea, she said, is to pay AstraZeneca up front so that manufacturing can start before it is known whether the vaccine candidate is safe or effective, the reverse of how the clinical trial process usually works.
That way, if the candidate is deemed safe and effective, time is not lost by then deciding how to make it and distribute it.
By the end of this year, she said, “Maybe we will have many vaccines made and stored in a refrigerator somewhere. But between now and December, there’s absolutely no way you can show efficacy of the vaccine at the same time you confirm that it’s safe.”
