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Tracker: The latest on COVID-19 vaccine front-runners

Ryan Huddle Globe staff / Adobe stock

After months of battling the pandemic, the first doses of a vaccine from Pfizer and BioNTech were administered across the United States on Dec. 14, kicking off the country’s mass distribution effort.

Inoculations of health care workers and those living in long-term care facilities are under way, but it will likely be months before most members of the public have access. Meanwhile, a number of drug companies and laboratories continue their efforts to get more vaccines authorized.

Each prospective vaccine goes through three phases of study in humans. To speed the process, some developers are conducting two of the phases simultaneously.


Phase 1: Trials involve small numbers of people, testing whether the vaccine is safe and provokes an immune response.

Phase 2: Trials expand to hundreds of people, comparing the vaccine’s effects in different groups and further testing its safety.

Phase 3: Trials enroll many thousands of people, to see if those who receive the vaccine are less likely to become infected than those who receive a placebo.

Emergency Use Authorization: The US Food and Drug Administration is granting COVID-19 vaccine candidates emergency use authorization, which means they can be used even though they have not been officially approved.

Below is a subset of notable vaccine candidates that either have ties to New England, have major funding behind them and the ability to move markets, or reflect a diversity of approaches.

Cambridge, Mass. • Phase 3    


Status of clinical trials: Authorized for use in the US, Canada, Israel, EU, Switzerland. Phase 3 trial started in July

Efficacy: 94.1 percent

Dose: 2 shots, 4 weeks apart

The FDA cleared Moderna’s vaccine for emergency use on Dec. 18, a week after Pfizer’s authorization, making it the second vaccine available in the US. A panel of outside experts recommended the FDA authorize Moderna’s vaccine the day before.


The vaccine has since been authorized in Canada, Israel, and the European Union.

Moderna said on Dec. 11 the US government exercised an option to buy 100 million additional doses of its COVID-19 vaccine, doubling the amount it initially agreed to purchase. Moderna chief executive Stephane Bancel has said the Cambridge biotech could deliver 100 million doses to the US government in the “first few months of 2021.” As of Jan. 4, the company said approximately 18 million doses have been supplied to the US.

Moderna said on Jan. 12 it is working with Uber Technologies Inc. — the company known for its ride-share app — to provide vaccine information through its app, eventually scheduling rides to appointments.

Approach: The Moderna technology — called messenger RNA — inserts portions of the virus’s RNA into cells, which then manufacture a piece of the virus to trigger an immune response. The company set a drug industry record by producing its vaccine in 42 days after receiving the genetic sequence of the virus that causes COVID-19.

Funding: On Aug. 11, the government awarded Moderna $1.5 billion for 100 million doses if the vaccine proves safe and effective. This funding came in addition to the almost $1 billion already provided by the Biomedical Advanced Research and Development Authority.

Updated Jan. 12

New York City | Germany • Phase 3    

Pfizer and BioNTech

Status of clinical trials: Authorized for use in US, UK, Canada, other countries. Phase 3 trial


Efficacy: 95 percent

Dose: 2 shots, 3 weeks apart

The FDA authorized emergency use of the Pfizer-BioNTech COVID-19 vaccine on Dec. 11, the first vaccine authorized in the US.

When it was cleared in the US, it already had been authorized elsewhere: Britain’s drug regulator granted Pfizer its first emergency-use approval on Dec. 2, and Bahrain said it became the second later that week. On Dec. 9, Canada’s health regulator approved the vaccine, and it was cleared in Mexico on Dec. 11.

According to early findings of a study published Jan. 7, the Pfizer-BioNTech vaccine appears to work against a key mutation found in two highly contagious strains of the illness.

Documents released by the FDA on Dec. 8 suggest the Pfizer vaccine candidate provides strong protection against COVID-19 after the first dose, but experts said they still recommend patients get the second shot. On Dec. 23, Pfizer and BioNTech agreed in a nearly $2 billion deal to supply the US with an additional 100 million doses of the vaccine. The companies already had a contract to supply 100 million doses to the US under Operation Warp Speed.

Approach: Pfizer, which has a manufacturing plant in Andover, is deploying technology similar to Moderna’s: a messenger RNA vaccine that codes for the spike protein found on the surface of the coronavirus. BioNTech’s US headquarters is located in Cambridge.


Funding: Pfizer agreed to pay BioNTech $185 million upfront, and BioNTech has a debt financing agreement with the European Investment Bank.

Updated Jan. 7

Cambridge, England | Oxford, England • Phase 3    

AstraZeneca and the University of Oxford

Status of clinical trials: Authorized for use in UK, Argentina, India, Mexico. Phase 3 in the United Kingdom, Brazil, South Africa

Efficacy: 70 percent

Dose: 2 shots, 4 weeks apart

The UK authorized the vaccine from AstraZeneca and the University of Oxford on Dec. 30, as did Argentina. India followed suit on Jan. 3, and Mexico approved it on Jan. 4.

The results from a peer-reviewed study on the vaccine candidate published Dec. 8 suggest it is about 70 percent effective, but questions remain as to how well it works in older populations. The company temporarily halted its vaccine trails on Sept. 6 due to suspected adverse reaction in a participant.

Approach: In a partnership with the University of Oxford, the British-Swedish company has developed a vaccine that uses a weakened version of a common-cold virus to deliver coronavirus genes into cells to provoke an immune response.

Funding: BARDA has provided more than $1 billion in funding.

Updated Jan. 4

New Brunswick, N.J. • Phase 3    

Johnson & Johnson

Status of clinical trials: Phase 3 trial began in September

Dose: 1 shot

Johnson & Johnson said it expects early data from its clinical trial to be available by the end of January. Pending the outcome, the company said it could apply for FDA emergency use authorization in February. The US government said it would commit $1 billion for 100 million J&J doses if the vaccine is authorized.


On Oct. 12, STAT reported the study was paused due to an unexplained illness in a study participant, but the trial has since resumed. In November, J&J said it also began a clinical trial that would test the vaccine’s efficacy at two doses, instead of one.

Approach: The company developed the vaccine with the Center for Virology and Vaccine Research at Beth Israel Deaconess Medical Center in Boston. The vaccine uses a common-cold virus to deliver part of the coronavirus into cells to stimulate the immune system to fight off an infection.

Funding: In addition to the $1 billion commitment from the federal government, J&J and BARDA have invested more than $1 billion in the effort.

Updated Jan. 4

Gaithersburg, Md. • Phase 3    


Status of clinical trials: Phase 3 in the United Kingdom and US

Dose: 2 shots, 3 weeks apart

Novavax began a Phase 3 trial with 30,000 people in the US and Mexico for its COVID-19 vaccine candidate on Dec. 28. Its other Phase 3 trial in the UK began in September, and the company said early results are expected in the first quarter of 2021.

On Nov. 9, the FDA granted Maryland-based Novavax “Fast Track Designation” for its vaccine.

Approach: The company is expanding its manufacturing capacity and pursuing late-stage clinical trials. Its vaccine candidate uses protein nanoparticles, together with a proprietary compound, to generate and enhance the immune response.

Funding: The firm has been awarded $1.6 billion by the US government’s Operation Warp Speed, and previously received $388 million from the Coalition for Epidemic Preparedness Innovations.

Updated Dec. 28

Tubingen, Germany • Phase 2/3    


Status of clinical trials: Phase 2/3 in Germany

Dose: 2 shots, 4 weeks apart

On Dec. 14, CureVac said it launched a Phase 2/3 trial in Germany with plans to recruit more than 35,000 participants.

Approach: The firm, which has about 20 employees at its US hub in Boston, is manufacturing a vaccine candidate that relies on messenger RNA.

Funding: CureVac has received an $85 million loan from the lending arm of the European Union and a grant of up to $8.3 million from the Coalition for Epidemic Preparedness Innovations.

Updated Jan. 5

Paris | London • Phase 1/2    

Sanofi and GSK

Status of clinical trials: Phase 1/2 trials began in September

Sanofi and GSK planned to begin a Phase 3 trial in December, but on Dec. 11 the companies said they suffered a setback based on early data. Sanofi’s global medical head for vaccines told STAT News the problem relates to “inadequate results in older adults” from its candidate, which the company traced back to “an inadequate formulation of their vaccine.”

The companies plan to begin another Phase 2 trial in February, and a Phase 3 study could start in the second quarter of 2021. The setback will push the estimated timeline for distribution of the Sanofi-GSK vaccine from the first half of 2021 into the second half of the year, pending authorization.

Approach: The vaccine candidate builds on work the French drug giant did in the SARS epidemic and employs technology Sanofi used in one of its flu vaccines. Sanofi is using one of GSK’s proprietary adjuvants, an ingredient for vaccines that can create stronger and longer-lasting immunity.

Funding: BARDA has provided $30 million in funding and the US government’s Operation Warp Speed is providing up to $2.1 billion.

Updated Dec. 11

Beijing • Phase 3    

Sinovac Biotech

Status of clinical trials: Phase 3 trials in Brazil began in July, and Phase 3 trials began in Indonesia in August and Turkey in September

Efficacy: more than 50 percent

Dose: 2 shots, 2 weeks apart

At the end of December, the vaccine developed by the Chinese pharmaceutical firm was found to be more than 50 percent effective in a Brazilian clinical trial, but researchers delayed releasing more information at the request of Sinovac.

On Sept. 16, Sinovac submitted an application for a Phase 1/2 trial of the vaccine candidate in children. Sinovac signed a manufacturing deal to supply Indonesia with at least 40 million doses by March if the vaccine is approved.

Approach: The Sinovac vaccine, called CoronaVac, uses a whole coronavirus that has been inactivated, so that it will trigger an immune response without causing illness. Unlike most of the other vaccine candidates under study, this is a proven vaccine method. But such vaccines, which must be grown in cultures, take longer to manufacture than those based on the virus’s genetic material.

Funding: This spring, Sinovac received $15 million in private investment, as well as an $8.5 million loan from the Bank of Beijing.

Updated Dec. 24

Paris | Lexington, Mass. • Preclinical    

Sanofi and Translate Bio

Status of clinical trials: Preclinical, or not yet being tested in people

Approach: The companies are collaborating on messenger RNA vaccines in a partnership that expands on a 2018 deal to develop such vaccines for as many as five infectious diseases. Translate specializes in developing mRNA medicines.

Funding: Sanofi is paying Translate $425 million upfront. The companies hope to start a trial of a coronavirus vaccine in the fourth quarter of 2021.

Updated July 28

Kenilworth, N.J. • Preclinical    

Merck and IAVI

Status of clinical trials: Preclinical, or not yet being tested in people

Approach: The drug giant is partnering with the nonprofit IAVI on a coronavirus vaccine related to the company’s existing Ebola vaccine.

Funding: BARDA has provided $38 million.

Updated Jan. 5

Basel, Switzerland • Preclinical    


Status of clinical trials: Preclinical, or not yet being tested in people

Approach: A subsidiary of the Swiss pharmaceutical giant Novartis is collaborating with Massachusetts Eye and Ear and Massachusetts General Hospital on a vaccine that uses a harmless virus as a Trojan horse to deliver the genetic sequence of the coronavirus into human cells to produce an immune response.

Funding: The collaboration has received a $1 million donation from Boston Celtics co-owner Wyc Grousbeck.

Updated Jan. 5

Design by Ryan Huddle/Globe staff.

Felice J. Freyer can be reached at felice.freyer@globe.com. Follow her on Twitter @felicejfreyer. Jonathan Saltzman can be reached at jonathan.saltzman@globe.com. Anissa Gardizy can be reached at anissa.gardizy@globe.com. Follow her on Twitter @anissagardizy8.