SARS-CoV-2, the virus that causes COVID-19, was isolated in late 2019. Its genetic sequence was published on 11 January 2020, setting off an intense research effort to develop a COVID-19 vaccine. Vaccine development was expedited via unprecedented collaboration between academia, the pharmaceutical industry and governments. By June 2020, tens of billions of dollars were being invested to develop dozens of vaccine candidates and prepare for global vaccination programs. According to the Coalition for Epidemic Preparedness Innovations (CEPI), the geographic distribution of COVID‑19 vaccine development shows North American entities to have about 40% of the activity, compared to 30% in Asia and Australia, 26% in Europe, and a few projects in South America and Africa.

In February 2020, the World Health Organization (WHO) said it did not expect a vaccine against SARS‑CoV‑2 to become available in less than 18 months. Virologist Paul Offit commented that, in hindsight, the development of a safe and effective vaccine within 11 months was a remarkable feat. The rapidly growing infection rate of COVID‑19 worldwide during 2020 stimulated international alliances and government efforts to urgently organize resources to make multiple vaccines on shortened timelines; Four vaccine candidates entered human evaluation in March.

On 24 June 2020, China approved the CanSino vaccine for limited use in the military and two inactivated virus vaccines for emergency use in high-risk occupations. On 11 August 2020, Russia announced the approval of its Sputnik V vaccine for emergency use, though one month later only small amounts of the vaccine had been distributed for use outside of the phase 3 trial.

The Pfizer–BioNTech partnership submitted an Emergency Use Authorization (EUA) request to the U.S. Food and Drug Administration (FDA) for their mRNA vaccine on 20 November 2020. On 2 December 2020, the United Kingdom's Medicines and Healthcare products Regulatory Agency (MHRA) gave temporary regulatory approval for the Pfizer–BioNTech vaccine, becoming the first country to approve the vaccine and the first country in the Western world to approve the use of any COVID‑19 vaccine. The US and the EU followed later that month. The US also granted an EUA for the Moderna COVID-19 vaccine in December. Bahrain and the United Arab Emirates granted emergency marketing authorization for the Sinopharm BIBP vaccine.

On 31 March 2021, the Russian government announced that they had registered the first COVID‑19 vaccine for animals. Named Carnivac-Cov, it is an inactivated vaccine for carnivorous animals, including pets, aimed at preventing mutations that occur during the interspecies transmission of SARS-CoV-2.

In October 2022, China began administering an oral vaccine developed by CanSino Biologics using its adenovirus model.

Despite the availability of mRNA and viral vector vaccines, worldwide vaccine equity has not been achieved. The ongoing development and use of whole inactivated virus (WIV) and protein-based vaccines has been recommended, especially for use in developing countries, to dampen further waves of the pandemic.

Planning and investment Since 2020, vaccine development has been expedited via unprecedented collaboration in the multinational pharmaceutical industry and between governments. According to the Coalition for Epidemic Preparedness Innovations (CEPI), the geographic distribution of COVID‑19 vaccine development puts North American entities having about 40% of the activity compared to 30% in Asia and Australia, 26% in Europe, and a few projects in South America and Africa.

Commitment to first-in-human testing of a vaccine candidate represents a substantial capital cost for vaccine developers, estimated to be from million to million for a typical PhaseI trial program, but possibly as much as million. For comparison, during the Ebola virus epidemic of 2013–16, there were 37 vaccine candidates in urgent development with only one becoming a licensed vaccine at a total cost to confirm efficacy in PhaseII–III trials of about billion.

International organizations

Access to COVID‑19 Tools (ACT) Accelerator

National governments Canada announced million in funding for 96 vaccine research projects at Canadian companies and universities, with plans to establish a "vaccine bank" that could be used if another coronavirus outbreak occurs. A further investment of billion was added to support clinical trials and develop manufacturing and supply chains for vaccines. On 4May, the Canadian government committed million to the WHO's live streaming effort to raise billion for COVID‑19 vaccines and preparedness.

China provided low-rate loans to a vaccine developer through its central bank and "quickly made land available for the company" to build production plants. As of June 2020, six of the eleven COVID‑19 vaccine candidates in early-stage human testing were developed by Chinese organizations. Three Chinese vaccine companies and research institutes are supported by the government for financing research, conducting clinical trials, and manufacturing the most promising vaccine candidates, prioritizing rapid evidence of efficacy over safety. On 18 May, China had pledged billion to support overall efforts by the WHO for programs against COVID‑19. On 22 July, China announced plans to provide a US$1 billion loan to make its vaccine accessible for Latin America and the Caribbean. On 24 August, Chinese Premier Li Keqiang announced it would provide Cambodia, Laos, Myanmar, Thailand, and Vietnam priority access to the vaccine once it was distributed.

Great Britain formed a COVID‑19 vaccine task force in April 2020, to stimulate local efforts for accelerated development of a vaccine through collaborations of industry, universities, and government agencies. It encompassed every phase of development from research to manufacturing. The vaccine development initiatives at the University of Oxford and Imperial College of London were financed with million.

In the United States, the Biomedical Advanced Research and Development Authority (BARDA), a federal agency funding disease-fighting technology, announced investments of nearly billion to support American COVID‑19 vaccine development and manufacture of the most promising candidates. On 16 April, BARDA made a million investment in vaccine developer Moderna and its partner, Johnson & Johnson. BARDA has earmarked an additional billion for development. It will have a role in other programs for development of six to eight vaccine candidates destined for clinical study into 2021 by companies such as Sanofi Pasteur and Regeneron. On 15 May, the government announced funding for a fast-track program called Operation Warp Speed to place multiple vaccine candidates into clinical trials by the fall of 2020 and manufacture 300million doses of a licensed vaccine by January 2021. The project's chief advisor is Moncef Slaoui and its chief operating officer is General Gustave Perna. In June, the Warp Speed team said it would work with seven companies developing vaccine candidates: Moderna, Johnson & Johnson, Merck, Pfizer, the University of Oxford in collaboration with AstraZeneca, and two others, although Pfizer later stated that "all the investment for R&D was made by Pfizer at risk."

Pharmaceutical companies Large pharmaceutical companies with experience in making vaccines at scale, including Johnson & Johnson, AstraZeneca, and GlaxoSmithKline (GSK), formed alliances with biotechnology companies, governments, and universities to accelerate progression to an effective vaccine. To combine financial and manufacturing capabilities for a pandemic with adjuvanted vaccine technology, GSK joined with Sanofi in an uncommon partnership of multinational companies to support accelerated vaccine development.

By June 2020, tens of billions of dollars were invested by corporations, governments, international health organizations, and university research groups to develop dozens of vaccine candidates and prepare for global vaccination programs to immunize against COVID‑19 infection. The corporate investment and need to generate value for public shareholders raised concerns about a "market-based approach" in vaccine development, costly pricing of eventual licensed vaccines, preferred access for distribution first to affluent countries, and sparse or no distribution to where the pandemic is most aggressive, as predicted for densely populated, impoverished countries unable to afford vaccinations. The collaboration of the University of Oxford with AstraZeneca (a global pharmaceutical company based in the UK) raised concerns about price and sharing of eventual profits from international vaccine sales, arising from whether the British government and university as public partners had commercialization rights. AstraZeneca stated that initial pricing of its vaccine would not include a profit margin for the company while the pandemic was still expanding.

In June, AstraZeneca made a deal allowing CEPI and Gavi, the Vaccine Alliance to manufacture and distribute 300 million doses if its Oxford vaccine candidate proved to be safe and effective, reportedly increasing the company's total production capacity to over 2 billion doses per year. Commercialization of pandemic vaccines is a high-risk business venture, potentially losing billions of dollars in development and pre-market manufacturing costs if the candidate vaccines fail to be safe and effective. Pfizer indicated it was not interested in a government partnership, considering it to be a "third party" slowing progress. Further, there are concerns that rapid-development programslike Operation Warp Speedare choosing candidates mainly for their manufacturing advantages rather than optimal safety and efficacy.

Development CEPI classifies development stages for vaccines as "exploratory" (planning and designing a candidate, having no evaluation in vivo), "preclinical" (in vivo evaluation with preparation for manufacturing a compound to test in humans), or initiation of PhaseI safety studies in healthy people. Some 321 total vaccine candidates were in development as either confirmed projects in clinical trials or in early-stage "exploratory" or "preclinical" development, as of September.

Early development

After a coronavirus was isolated in December 2019, its genetic sequence was published on 11 January 2020, triggering an urgent international response to prepare for an outbreak and hasten development of a preventive vaccine.

In February 2020, the WHO said it did not expect a vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative virus, to become available in less than 18 months. The rapidly growing infection rate of COVID‑19 worldwide during 2020 stimulated international alliances and government efforts to urgently organize resources to make multiple vaccines on shortened timelines, with four vaccine candidates entering human evaluation in March (see the table of clinical trials started in 2020, below).

By April 2020, "almost 80 companies and institutes in 19 countries" were working on this virtual gold rush. Also in April, CEPI estimated that as many as six of the vaccine candidates against COVID‑19 should be chosen by international coalitions for development through PhaseII–III trials, and three should be streamlined through regulatory and quality assurance for eventual licensing at a total cost of at least billion. Another analysis estimates ten candidates will need simultaneous initial development, before a select few are chosen for the final path to licensing.

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