COVID-19 vaccines provide acquired immunity against SARS-CoV-2, the virus causing COVID-19. These vaccines are a crucial tool in combating the pandemic, reducing severe illness, hospitalization, and death. Various types, including mRNA, viral vector, and inactivated virus vaccines, have been developed and deployed globally. Vaccination efforts aim to achieve herd immunity, protecting vulnerable populations and curbing the spread of the virus. While highly effective, vaccines may cause side effects, typically mild and temporary. Boosters are recommended to maintain protection against emerging variants.
As of 2003, vaccines have been produced against several animal diseases caused by coronaviruses, including infectious bronchitis virus in birds, canine coronavirus, and feline coronavirus.
According to studies published in 2005, the identification and development of novel vaccines and medicines to treat SARS was a priority for governments and public health agencies around the world at that time.
According to studies published in 2006, the identification and development of novel vaccines and medicines to treat SARS was a priority for governments and public health agencies around the world at that time.
In 2015, Moderna began human testing of an mRNA vaccine.
SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2), the virus that causes COVID-19, was isolated in late 2019.
In January 2020, Chinese vaccine developers and the Chinese Center for Disease Control and Prevention began their efforts on short timelines.
On 11 January 2020, the genetic sequence of SARS-CoV-2 was published, triggering an urgent international response.
Since January 2020, vaccine development has been expedited via unprecedented collaboration in the multinational pharmaceutical industry and between governments.
In February 2020, the World Health Organization (WHO) estimated that a vaccine against SARS-CoV-2 would not be available for at least 18 months, highlighting the initial expectations for vaccine development timelines.
On February 4, 2020, liability shields took effect in the US when the Secretary of Health and Human Services published a notice of declaration under the Public Readiness and Emergency Preparedness Act (PREP Act) for medical countermeasures against COVID‑19.
As of March 2020, there was one (DNA-based) MERS vaccine that completed Phase I clinical trials in humans, and three others in progress.
In April 2020, the Access to COVID‑19 Tools Accelerator, a G20 and World Health Organization (WHO) initiative, was announced to enable partners to share resources and knowledge.
In April 2020, the UK agreed to work with 20 other countries and global organizations to find a vaccine and share the results, ensuring UK citizens would not receive preferential access to taxpayer-funded vaccines. Some companies planned tiered pricing for profitability.
In April 2020, the United Kingdom government formed a COVID‑19 vaccine task force to stimulate local efforts for accelerated development of a vaccine through collaborations.
In May 2020, the US government announced funding for a fast-track program called Operation Warp Speed to support American COVID‑19 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.
On 24 June 2020, China approved the CanSino vaccine for limited use in the military along with two inactivated virus vaccines for emergency use in high-risk occupations.
In August 2020, Russia announced the approval of its Sputnik V vaccine for emergency use, although distribution remained limited outside of phase 3 trials in the following month.
As of September 2020, eleven of the vaccine candidates in clinical development use adjuvants to enhance immunogenicity.
In October 2020, a waiver was proposed to the TRIPS agreement related to intellectual property rights for COVID-19 vaccines, gaining support from most countries but facing delays due to opposition from the EU, the UK, Norway, and Switzerland.
As of 15 November 2020, high-income nations, representing only 14% of the global population, had contracted to buy 51% of all pre-sold COVID‑19 vaccine doses, with some buying more than necessary for their entire populations.
In November 2020, the Pfizer–BioNTech partnership submitted an Emergency Use Authorization (EUA) request to the U.S. Food and Drug Administration (FDA) for their mRNA vaccine BNT162b2.
By December 2020, more than 10 billion COVID-19 vaccine doses had been preordered by countries, with about half purchased by high-income countries.
From 8 December 2020 to 8 December 2021, COVID‑19 vaccines prevented an additional 14.4 to 19.8 million deaths in 185 countries and territories.
In December 2020, 1,893,360 first doses of Pfizer–BioNTech COVID‑19 vaccine administration resulted in 175 cases of severe allergic reactions, of which 21 were anaphylaxis.
In December 2020, the UK government granted Pfizer legal indemnity for its COVID‑19 vaccine.
In December 2020, the United Kingdom became the first country to approve the Pfizer–BioNTech vaccine. The FDA also granted an EUA for the Pfizer–BioNTech COVID‑19 vaccine. Bahrain and the United Arab Emirates granted emergency marketing authorization for the Sinopharm BIBP vaccine, and the FDA granted an EUA for the Moderna vaccine
During the rapid COVID-19 pandemic in 2020, international organizations, vaccine developers, governments, and industry evaluated the distribution of eventual vaccines, emphasizing the need for availability and affordability, especially for frontline healthcare workers and those in need.
In 2020 vaccine platforms involved nucleic acid technologies (nucleoside-modified messenger RNA and DNA), non-replicating viral vectors, peptides, recombinant proteins, live attenuated viruses, and inactivated viruses.
In 2020, the first COVID-19 vaccines were developed and made available to the public through emergency authorizations and conditional approvals.
For 4,041,396 Moderna COVID‑19 vaccine dose administrations in January 2021, only ten cases of anaphylaxis were reported.
In January 2021, WHO Director-General Tedros Adhanom Ghebreyesus highlighted the vast disparity in vaccine distribution, noting that while over 39 million doses had been administered in higher-income countries, only 25 doses had been given in one lowest-income country.
By March 2021, BARDA had funded an estimated $19.3 billion in COVID‑19 vaccine development.
In March 2021, Brazilian journalism agency Agência Pública reported that the country vaccinated about twice as many people who declare themselves white than black, and that mortality from COVID‑19 is higher in the black population.
In March 2021, Covaxx raised $1.35 billion in a private placement.
In March 2021, it was revealed that the US attempted to discourage Brazil from purchasing the Sputnik V COVID‑19 vaccine, citing concerns over "Russian influence." Additionally, access to vaccines was reportedly blocked in nations with territorial disputes, such as Palestine and Taiwan.
In March 2021, the United States, Britain, European Union member states, and some other members of the World Trade Organization (WTO) blocked a push by more than eighty developing countries to waive COVID‑19 vaccine patent rights.
On 31 March 2021, the Russian government announced the registration of Carnivac-Cov, the first COVID‑19 vaccine for animals, designed to prevent mutations during interspecies transmission of SARS-CoV-2.
In April 2021, the World Health Organization's emergency committee addressed concerns of persistent inequity in global vaccine distribution. The 29 poorest countries, home to 9% of the world's population, had received only 0.3% of all vaccines administered as of May 2021.
In April 2021, the World Health Organization's emergency committee addressed concerns of persistent inequity in global vaccine distribution. As of May 2021, The 29 poorest countries, home to 9% of the world's population, had received only 0.3% of all vaccines administered .
In May 2021, UNICEF urgently appealed to industrialized nations to pool excess COVID‑19 vaccine capacity to address a 125-million-dose gap in the COVAX program, which faced supply problems from the Serum Institute of India. There was a lack of expedient donations by richer nations.
On 5 May 2021, the US government under President Joe Biden announced that it supports waiving intellectual property protections for COVID‑19 vaccines. The Members of the European Parliament also backed a motion demanding the temporary lifting of intellectual property rights for COVID‑19 vaccines.
In June 2021, a report uncovered that the UB-612 vaccine, developed by Covaxx, was a for-profit venture initiated by Blackwater founder Erik Prince, who aimed to profit from selling COVID‑19 vaccines. Covaxx provided no data from the clinical trials on safety or efficacy it conducted in Taiwan.
As of July 2021, at least nine different technology platforms were under research and development to create an effective vaccine against COVID-19.
In July 2021, multiple organizations expressed deep concerns about the limited access to vaccines, therapeutics, and diagnostics in developing countries. Also in July 2021, The BMJ reported that some countries had discarded over 250,000 vaccine doses due to supply exceeding demand and strict regulations. Additionally, India announced it would make its CoWIN platform and Aarogya Setu app available globally.
In August 2021, the CDC reported that vaccine effectiveness fell from 91% against the Alpha variant to 66% against the Delta variant, which accounted for 99 percent of US cases. The Delta variant was found to double the risk of severe illness and hospitalization for those not yet vaccinated.
In August 2021, the WHO called for a moratorium on booster doses until the end of September to reduce unequal distribution, while the US announced plans to offer booster doses. The WHO criticized the booster plans, citing lack of evidence, with a large disparity in vaccine coverage between high and low-income countries at the time.
In August 2021, the developers of Sputnik V proposed, in view of the Delta case surge, that Pfizer test the Ad26 component (termed its 'Light' version) as a booster shot.
In September 2021, MSF called for a Day of Action to pressure the WTO Minister's meeting in November to discuss the TRIPS IP waiver.
In September 2021, it was reported that vaccine inequity damages the global economy by disrupting the supply chain. Wealthy countries reserved most vaccines, leading to under-vaccination, death, disability, and lockdown restrictions in other countries. High-income countries could profit US$4.80 for every $1 spent on giving vaccines to lower-income countries.
In September 2021, over 140 former world leaders and Nobel laureates urged the candidates to be the next German chancellor to support waiving intellectual property rules for COVID-19 vaccines.
On September 21, 2021, the President of Peru, Pedro Castillo, proposed at the United Nations General Assembly the creation of an international treaty to guarantee universal vaccine access.
In October 2021, The first authorised intranasal vaccine was Razi Cov Pars in Iran.
In November 2021, nursing unions in 28 countries formally appealed to the United Nations, protesting the refusal of the UK, EU, Norway, Switzerland, and Singapore to temporarily waive patents for COVID-19 vaccines.
In November 2021, the ECDC estimated that 470,000 lives over the age of 60 had been saved since the start of the vaccination roll-out in the European region.
In November 2021, the full nucleotide sequences of the AstraZeneca and Pfizer/BioNTech vaccines were released by the UK Medicines and Healthcare products Regulatory Agency in response to a freedom of information request.
According to early December 2021 CDC data, "unvaccinated adults were about 97 times more likely to die from COVID-19 than fully vaccinated people who had received boosters".
As of December 2021, there were no FDA-authorized or approved tests available for providers or the public to reliably determine if a person was protected from infection.
From 8 December 2020 to 8 December 2021, COVID‑19 vaccines prevented an additional 14.4 to 19.8 million deaths in 185 countries and territories.
On 10 December 2021, the UK Health Security Agency reported that early data indicated a 20- to 40-fold reduction in neutralizing activity for Omicron by sera from Pfizer 2-dose vaccinees relative to earlier strains. Booster doses improved vaccine effectiveness.
As of 2021, fully vaccinated individuals and those previously infected with SARS-CoV-2 had a low risk of subsequent infection for at least six months, but individual protection titers remained unknown and protection levels varied among populations and virus variants.
In 2021, evidence showed that COVID-19 vaccination reduced infection and was effective at preventing severe symptoms and death, although less effective against mild cases; efficacy waned over time but could be maintained with boosters. Unvaccinated people were significantly more likely to be hospitalized or die compared to fully vaccinated individuals.
As of March 2022, elderly residents' protection against severe illness, hospitalization, and death in English care homes was high immediately after vaccination, but protection declined significantly in the months following vaccination. Regular boosters were recommended, especially for older people.
In March 2022, data indicated that only 1% of the 10 billion COVID-19 vaccine doses given worldwide had been administered in low-income countries, despite the WHO's goal of vaccinating 70% of the global population by mid-2022.
In March 2022, the White House released the "National COVID‑19 Preparedness Plan", which recommended accelerating the development of a universal coronavirus vaccine.
As of March 2022, the US Centers for Disease Control and Prevention (CDC) recommended a fourth dose of the Pfizer mRNA vaccine for "certain immunocompromised individuals and people over the age of 50".
In April 2022, the first viral component of Sputnik V vaccine was authorised in Russia as Sputnik Nasal.
In April 2022, the spike ferritin-based nanoparticle (SpFN) vaccine began a Phase I clinical trial.
On 5 May 2022 the FDA posted a bulletin limiting the use of the Janssen Vaccine to very specific cases due to further reassessment of the risks of TTS.
A June 2022 study estimated that COVID‑19 vaccines prevented an additional 14.4 to 19.8 million deaths in 185 countries and territories from 8 December 2020 to 8 December 2021.
In June 2022, Pfizer and Moderna developed bivalent vaccines to protect against the SARS-CoV-2 wild-type and the Omicron variant, offering superior immunity to Omicron compared to previous mRNA vaccines.
As of September 2022, 70.6 percent of the global population had received at least one COVID-19 vaccine dose, but only 22.3 percent of people in low-income countries had received at least a first vaccine.
In September 2022, the COVID‑19 vaccines conditional marketing authorizations in the European Union were changed to standard authorizations.
In September 2022, the United States Food and Drug Administration (FDA) authorized the bivalent vaccines developed by Pfizer and Moderna.
In October 2022, China began administering an oral vaccine developed by CanSino Biologics using its adenovirus model.
As of November 2022, 40 vaccines are authorized by at least one national regulatory authority for public use.
In December 2022, China approved a second intranasal vaccine as a booster, trade name Pneucolin.
On December 13, 2022, Florida Governor Ron DeSantis announced he would petition the state supreme court to convene a grand jury to investigate possible violations related to COVID‑19 vaccines.
As of 2022, fully vaccinated individuals with breakthrough infections from the SARS-CoV-2 delta (B.1.617.2) variant have a peak viral load similar to unvaccinated cases and can transmit infection in household settings.
In February 2023, a systematic review in The Lancet found that protection from prior infection was comparable to that from vaccination, with the caveat of increased risks from the initial infection.
In March 2023, Bimervax (selvacovatein) was approved for use as a booster vaccine in the European Union.
In June 2023, the FDA advised manufacturers that the 2023–2024 formulation of the COVID‑19 vaccines for use in the US be updated to be a monovalent COVID‑19 vaccine using the XBB.1.5 lineage of the Omicron variant.
In 2023, the Nobel Prize in Physiology or Medicine was awarded to Katalin Karikó and Drew Weissman for the development of effective mRNA vaccines against COVID-19.
In May 2024, results of the Walter Reed Army Institute of Research SpFN vaccine Phase I clinical trial were published.
In June 2024, the FDA advised manufacturers that the 2024–2025 formulation of the COVID‑19 vaccines for use in the US be updated to be a monovalent COVID‑19 vaccine using the JN.1 lineage.
In June 2024, the US Food and Drug Administration (FDA) advised the manufacturers of the licensed and authorized COVID-19 vaccines that the COVID-19 vaccines (2024-2025 Formula) for use in the United States beginning in fall 2024 should be monovalent JN.1 vaccines.
As of 12 August 2024, 13.53 billion COVID-19 vaccine doses have been administered worldwide, with 70.6 percent of the global population having received at least one dose.
As of August 2024, 13.72 billion doses of COVID‑19 vaccines have been administered worldwide, based on official reports from national public health agencies.
The declaration that precludes "liability claims alleging negligence by a manufacturer in creating a vaccine, or negligence by a health care provider in prescribing the wrong dose, absent willful misconduct" is effective in the United States through 1 October 2024.
In June 2024, the US Food and Drug Administration (FDA) advised the manufacturers of the licensed and authorized COVID-19 vaccines that the COVID-19 vaccines (2024-2025 Formula) for use in the United States beginning in fall 2024 should be monovalent JN.1 vaccines.