Even as the world — and investors — await a coronavirus vaccine, the timeline has become increasingly hard to gauge given clinical setbacks and the risks inherent with fast development. 

An analyst at Canaccord Genuity said a year-end timeline looks a possibility, going by two key events scheduled for this month. 

Upcoming FDA, CDC Meetings: With five SARS-CoV-2 vaccine candidates in pivotal Phase 3 trials, two meetings scheduled for late October could be the key, Canaccord analyst Arlinda Lee said in a note. 

The FDA's Vaccines and Related Biological Products Advisory Committee is scheduled to meet between 10 a.m. and 5 p.m. on Oct. 22 to discuss the development, authorization and/or licensure of vaccines to prevent COVID-19.

Also on tap is the CDC's Advisory Committee on Immunization Practices meeting. The AICP panel will meet Oct. 28-30, which is one of its customary three yearly meetings to review scientific data and vote on vaccine recommendations.

Related Link: Attention Biotech Investors: Mark Your Calendar For October PDUFA Dates

The Late-Stage Coronavirus Vaccine Programs: AstraZeneca plc's (NASDAQ:AZN) ChAdOx1 nCoV-19, a chimpanzee adenovirus expressing SARS-CoV-2 spike, is in late-stage trials in the U.K., India and South Africa.

The late-stage study in the U.K. was voluntarily paused briefly due to an adverse event in one of the study participants.

The U.S. leg of the study remains halted, with a Reuters report suggesting the FDA has widened the scope of its probe into the halted trial.

Pfizer Inc. (NYSE:PFE) and BioNTech SE – ADR (NASDAQ:BNTX), which are collaborating on a mRNA vaccine against SARS-CoV-2, recently amended its Phase 3 study protocol to increase the targeted enrollment from 30,000 to 44,000.

The increase was to accommodate a diverse population.

Recently, BioNTech announced plans to acquire Novartis AG's (NYSE:NVS) GMP-certified manufacturing facility in Germany, which would increase its COVID-19 vaccine production capacity by up to 750 million doses per year.

Johnson & Johnson (NYSE:JNJ) initiated a Phase 3 study of its coronavirus vaccine candidate JNJ-78436735 on Sept. 23.

JNJ-78436735 is manufactured using J&J's AdVac technology platform, which was used to develop and manufacture its Janssen unit's European Commission-approved Ebola vaccine.

The company has an early 2021 timeline for emergency use authorization. 

Novavax, Inc. (NASDAQ:NVAX) has an ongoing Phase 3 study of its NVX-CoV2373, a recombinant nanoparticle vaccine, in the U.K.

The company plans to start a late-stage study in the U.S. in October.