Vaccine - Who should get COVID-19 boosters first? CDC committee set to vote Thursday – but only on Pfizer vaccine
January 24 2022
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Who should get COVID-19 boosters first? CDC committee set to vote Thursday – but only on Pfizer vaccine

Story by Elizabeth Weise and Karen Weintraub

Story   Source

Published on September 23, 2021 2:27 AM
Only the Pfizer-BioNTech vaccine, now called Comirnaty, would be authorized for the new booster shots, because there is much less data on the long-term effectiveness of the other two authorized shots, from Moderna and Johnson & Johnson. People who are severely immunocompromised and might not have gotten protection from the first two doses, have been able to get a third dose for the past six weeks or so.
A committee of experts spent more than five hours Wednesday reviewing data on the safety and effectiveness of a third shot of the Pfizer-BioNTech COVID-19 vaccine.

The committee, which advises the Centers for Disease Control and Prevention, is scheduled to vote Thursday on precisely who should be eligible for a third shot.

Wednesday night, the Food and Drug Administration authorized a third Pfizer-BioNTech shot six months after the second for people 65-and-older, younger people at high risk for severe disease and those whose jobs put them at extra risk for infection.

The CDC advisory panel, called the Advisory Committee on Immunization Practices, will decide Thursday how to implement that expanded access. CDC director Dr. Rochelle Walensky is expected to quickly sign off on whatever the committee decides, making boosters available to more people within a few days...

Pfizer–BioNTech COVID-19 vaccine

The Pfizer–BioNTech COVID-19 vaccine , sold under the brand name Comirnaty, is an mRNA-based COVID-19 vaccine developed by the German biotechnology company BioNTech and for it's development collaborated with American company Pfizer, for support with clinical trials, logistics, and manufacturing. It is authorized for use in people aged twelve years and older in some jurisdictions and for people sixteen years and older in other jurisdictions, to provide protection against COVID-19, caused by infection with the SARS-CoV-2 virus. The vaccine is given by intramuscular injection. It is composed of nucleoside-modified mRNA encoding a mutated form of the full-length spike protein of SARS-CoV-2, which is encapsulated in lipid nanoparticles. Initial advice indicated that vaccination required two doses given 21 days apart, but the interval was later extended to up to 42 days in the US, and up to four months in Canada.

Clinical trials began in April 2020; by November 2020, the vaccine entered Phase III clinical trials, with over 40,000 people participating. An interim analysis of study data showed a potential efficacy of 91.3% in preventing symptomatic infection within seven days of a second dose. The most common side effects include mild to moderate pain at the injection site, fatigue, and headaches. Reports of serious side effects, such as allergic reactions, are very rare; no long-term complications have been reported. Monitoring of the primary outcomes from the trials continued until August 2021, while monitoring of the secondary outcomes will continue until May 2023. As part of the updates for the Phase III clinical trials posted in June 2021, the assessment of biostability will be studied to further describe the potential protection given by the vaccine against emerging SARS-CoV-2 Variants of Concern.

The vaccine is the first COVID-19 vaccine to be authorized by a stringent regulatory authority for emergency use and the first cleared for regular use. In December 2020, the United Kingdom was the first country to authorize its use on an emergency basis. It is authorized for use at some level in the majority of countries. On 23 August 2021, the Pfizer–BioNTech vaccine became the first COVID-19 vaccine to be approved in the United States by the Food and Drug Administration for those aged sixteen years and older.

As of 30 March 2021, Pfizer and BioNTech aimed to manufacture about 2.5 billion doses in 2021. Distribution and storage is a logistical challenge because the vaccine needs to be stored at extremely low temperatures. BioNTech and Pfizer are testing a freeze-dried version that would not need ultracold storage.

Medical uses
The Pfizer–BioNTech COVID-19 vaccine is used to provide protection against COVID-19, caused by infection with the SARS-CoV-2 virus, by eliciting an immune response to the S antigen. The vaccine is used to reduce morbidity and mortality from COVID-19.

The vaccine is supplied in a multidose vial as 'a white to off-white, sterile, preservative-free, frozen suspension for intramuscular injection'. It must be thawed to room temperature and diluted with normal saline before administration.

The initial course consists of two doses. The World Health Organization recommends an interval of three to four weeks between doses. Delaying the second dose by up to twelve weeks increases immunogenicity, even in older adults, against all variants of concern. Authors of the Pitch study think that the optimal interval against the Delta variant is around eight weeks, with longer intervals leaving receptors vulnerable between doses. To avoid deaths where supplies are limited, the WHO recommends delaying the second dose by up to twelve weeks to achieve high coverage of the first dose in high priority groups earlier.

There is no evidence that a third booster dose is needed to prevent severe disease in healthy adults. A third dose can be added after 28 days for immunocompromised people in some countries.

A case-control study published in May 2021, in The New England Journal of Medicine found that, among vaccine recipients in Qatar, the Pfizer-BioNTech vaccine has an effectiveness of 89.5% against any documented cases of the Alpha variant and 75% effectiveness against the Beta variant . The same study reported that the effectiveness of the vaccine against severe, critical, or fatal disease against any variant of SARS-CoV-2 is 97.4%.

A test-negative case-control study published in August 2021 found that two doses of the BNT162b2 vaccine had 93.7% effectiveness against symptomatic disease caused by the alpha variant and 88.0% effectiveness against symptomatic disease caused by the delta variant. Notably, effectiveness after one dose of the Pfizer vaccine was 48.7% against alpha and 30.7% against delta, similar to effectiveness provided by one dose of the ChAdOx1 nCoV-19 vaccine.

On 27 August, the Centers for Disease Control and Prevention published a study reporting that the effectiveness against infection decreased from 91% to 66% when the Delta variant became predominant in the US, which may be due to unmeasured and residual confounding related to a decline in vaccine effectiveness over time.

Unless indicated otherwise, the following effectiveness ratings are indicative of clinical effectiveness two weeks after the second dose. A vaccine is generally considered effective if the estimate is =50% with a >30% lower limit of the 95% confidence interval. Effectiveness is generally expected to slowly decrease over time.

Specific populations
Based on the results of a preliminary study, the U.S. Centers for Disease Control and Prevention recommends that pregnant women get vaccinated with the COVID-19 vaccine.

A statement by the British Medicines and Healthcare products Regulatory Agency and the Commission on Human Medicines reported that the two agencies had reached a conclusion that the vaccine is safe and effective in children aged between 12 and 15 years.

On 19 May 2021, experts commissioned by the Norwegian Medicines Agency concluded that the Pfizer-BioNTech vaccine is the likely cause of 10 deaths of frail elderly patients in Norwegian nursing homes. They said that people with very short life expectancies have little to gain from vaccination, having a real risk of adverse reactions in the last days of life and of dying earlier.

A 2021 report by the New South Wales Government in Australia found that the Pfizer-BioNTech vaccine is safe for those suffering from various forms of immunodeficiency or immunosuppression, though it does note that the data on said groups is limited, due to their exclusion from many of the vaccine earlier trials held in 2020. It notes that the World Health Organization advises that the vaccine is among the three COVID-19 vaccines it deems safe to give to immunocompromised individuals, and that expert consensus generally recommends their vaccination. The report states that the vaccines were able to generate an immune response in those individuals, though it does also note that this response is weaker than in those that are not immunocompromised. It recommends that specific patient groups, such as those suffering from cancer, inflammatory bowel disease and various liver diseases be prioritised in the vaccination schedules over other patients that do not suffer from said conditions.

Adverse effects
In large phase 3 trials for the vaccine there were no reported serious safety findings, and it observed low incidence of serious adverse events. However, rare or serious outcomes associated with a vaccine may not be identified in phase 3 trials because of limited sample size, restrictive inclusion criteria, limited duration of follow-up, and trial participants who may differ from the population ultimately receiving the vaccine. Furthermore, there is limited experience with mRNA platforms.

The side effect profile of the Pfizer–BioNTech COVID-19 vaccine is similar to that of other adult vaccines. During clinical trials, the side effects deemed very common are : pain and swelling at the injection site, tiredness, headache, muscle aches, chills, joint pain, and fever. Fever is more common after the second dose.

Documented hypersensitivity to polyethylene glycol is listed as a contraindication to the COVID-19 Pfizer vaccine. Severe allergic reaction has been observed in approximately eleven cases per million doses of vaccine administered. According to a report by the US Centers for Disease Control and Prevention, 71% of those allergic reactions happened within 15 minutes of vaccination and mostly among people with a documented history of allergies or allergic reactions. The UK's Medicines and Healthcare products Regulatory Agency advised on 9 December 2020 that people who have a history of 'significant' allergic reaction should not receive the Pfizer–BioNTech COVID-19 vaccine. On 12 December, the Canadian regulator followed suit, noting that: 'Both individuals in the U.K. had a history of severe allergic reactions and carried adrenaline auto injectors. They both were treated and have recovered.'

The European Medicines Agency regularly reviews the data on the vaccine's safety. In a report published on 4 March 2021, it concluded that 'the benefits of Comirnaty in preventing COVID-19 continue to outweigh any risks, and there are no recommended changes regarding the use of this vaccine.' The EMA added skin rash and pruritus as uncommon side effects , and urticaria and angioedema as rare side effects in April 2021.

According to Israel's Ministry of Health there is a probable relationship between the second dose and myocarditis in a small group of 16–30-year-old men. Between December 2020 and May 2021, there were 55 cases of myocarditis per 1 million people vaccinated, 95% of which were classified as mild. Since April 2021, increased cases of myocarditis and pericarditis have been reported in the United States in about 13 per 1 million young people, mostly male and over the age of 16, after vaccination with the Pfizer–BioNTech or the Moderna vaccine. Most affected individuals recover quickly with adequate treatment and rest.

See also: RNA vaccine and COVID-19 vaccine § Technology platforms The BioNTech technology for the BNT162b2 vaccine is based on use of nucleoside-modified mRNA which encodes a mutated form of the full-length spike protein found on the surface of the SARS-CoV-2 virus, triggering an immune response against infection by the virus protein.

The modRNA sequence of the vaccine is 4,284 nucleotides long. It consists of a five-prime cap; a five prime untranslated region derived from the sequence of human alpha globin; a signal peptide and two proline substitutions that cause the spike to adopt a prefusion-stabilized conformation reducing the membrane fusion ability, increasing expression and stimulating neutralizing antibodies; a codon-optimized gene of the full-length spike protein of SARS-CoV-2 ; followed by a three prime untranslated region combined from AES and mtRNR1 selected for increased protein expression and mRNA stability and a poly tail comprising 30 adenosine residues, a 10-nucleotide linker sequence, and 70 other adenosine residues . The sequence contains no uridine residues; they are replaced by 1-methyl-3'-pseudouridylyl. The 2P proline substitutions in the spike proteins were originally developed for a MERS vaccine by researchers at the National Institute of Allergy and Infectious Diseases' Vaccine Research Center, Scripps Research, and Jason McLellan's team .

Pfizer and BioNTech are manufacturing the vaccine in their own facilities in the United States and in Europe. The license to distribute and manufacture the vaccine in China was purchased by Fosun, alongside its investment in BioNTech.

Pfizer indicated in its 9 November press release that 50 million doses could be available by the end of 2020, with about 1.3 billion doses provided globally by 2021.

Manufacturing the vaccine requires a three-stage process. The first stage involves the molecular cloning of DNA plasmids that code for the spike protein by infusing them into Escherichia coli bacteria. For all markets, this stage is conducted in the United States, at a small Pfizer pilot plant in Chesterfield, Missouri . After four days of growth, the bacteria are killed and broken open, and the contents of their cells are purified over a week and a half to recover the desired DNA product. The DNA is bottled and frozen for shipment. Safely and quickly transporting the DNA at this stage is so important that Pfizer has used its company jet and helicopter to assist.

The second stage is being conducted at a Pfizer plant in Andover, Massachusetts, in the United States, and at BioNTech's plants in Germany. The DNA is used as a template to build the desired mRNA strands, which takes about four days. Once the mRNA has been created and purified, it is frozen in plastic bags about the size of a large shopping bag, of which each can hold up to 10 million doses. The bags are placed on trucks which take them to the next plant.

The third stage is being conducted at Pfizer plants in Portage, Michigan in the United States, and Puurs in Belgium. This stage involves combining the mRNA with lipid nanoparticles, then filling vials, boxing vials, and freezing them. Croda International subsidiary Avanti Polar Lipids is providing the requisite lipids. As of November 2020, the major bottleneck in the manufacturing process is combining mRNA with lipid nanoparticles. At this stage, it takes only four days to go from mRNA and lipids to finished vials, but each lot must then spend several weeks in deep-freeze storage while undergoing verification against 40 quality-control measures.

Before May 2021, the Pfizer plant in Puurs was responsible for all vials for destinations outside the United States. Therefore, all doses administered in the Americas outside of the United States before that point in time required at least two transatlantic flights .

In February 2021, BioNTech announced it would increase production by more than 50% to manufacture 2 billion doses in 2021, raised again at the end of March to 2.5 billion doses in 2021.

In February 2021, Pfizer revealed that the entire sequence initially took about 110 days on average from start to finish, and that the company is making progress on reducing the time to 60 days. More than half the days in the production process are dedicated to rigorous testing and quality assurance at each of the three stages. Pfizer also revealed that the process requires 280 components and relies upon 25 suppliers located in 19 different countries.

Vaccine manufacturers normally take several years to optimize the process of making a particular vaccine for speed and cost-effectiveness before attempting large-scale production. Due to the urgency presented by the COVID-19 pandemic, Pfizer and BioNTech began production immediately with the process by which the vaccine had been originally formulated in the laboratory, then started to identify ways to safely speed up and scale up that process.

BioNTech announced in September 2020, that it had signed an agreement to acquire a manufacturing facility in Marburg, Germany, from Novartis to expand their vaccine production capacity. Once fully operational, the facility would produce up to 750 million doses per year, or more than 60 million doses per month. The site will be the third BioNTech facility in Europe that produces the vaccine, while Pfizer operates at least four production sites in the United States and Europe.

The Marburg facility had previously specialized in cancer immunotherapy for Novartis. By the end of March 2021, BioNTech had finished retrofitting the facility for mRNA vaccine production and retraining its 300 staff, and obtained approval to begin manufacturing. Besides making mRNA, the Marburg facility also performs the step of combining mRNA with lipids to form lipid nanoparticles, then ships the vaccine in bulk to other facilities for fill and finish .

On 23 April 2021, the EMA authorised an increase in batch size and associated process scale up at Pfizer's plant in Puurs. This increase is expected to have a significant impact on the supply of the vaccine in the European Union.

At the end of April 2021, it was reported that Pfizer had started to export vaccine doses to Mexico and Canada from the Kalamazoo plant, which is much closer geographically to both countries than the Puurs plant.

The vaccine is delivered in vials that, once diluted, contain 2.25 ml of vaccine, comprising 0.45 ml frozen and 1.8 ml diluent. According to the vial labels, each vial contains five 0.3 ml doses, however excess vaccine may be used for one, or possibly two, additional doses. The use of low dead space syringes to obtain the additional doses is preferable, and partial doses within a vial should be discarded. The Italian Medicines Agency officially authorized the use of excess doses remaining within single vials. The Danish Health Authority allows mixing partial doses from two vials. As of 8 January 2021, each vial contains six doses. In the United States, vials will be counted as five doses when accompanied by regular syringes and as six doses when accompanied by low dead space syringes.

Low-income countries have limited cold chain capacity for ultracold transport and storage of a vaccine. The necessary storage temperatures for the vaccine are much lower than for the similar Moderna vaccine. The head of Indonesia's Bio Farma Honesti Basyir said purchasing the vaccine is out of the question for the world's fourth-most populous country, given that it did not have the necessary cold chain capability. Similarly, India's existing cold chain network can handle only temperatures between 2 and 8 °C , far above the requirements of the vaccine.

Before COVID-19 vaccines, a vaccine for an infectious disease had never before been produced in less than several years, and no vaccine existed for preventing a coronavirus infection in humans. The SARS-CoV-2 virus, which causes COVID-19, was detected in December 2019, and BioNTech began development of a COVID-19 vaccine on 10 January 2020, when the SARS-CoV-2 genetic sequences were released by the Chinese Center for Disease Control and Prevention via GISAID, triggering an urgent international response to prepare for an outbreak and hasten development of preventive vaccines. The vaccine's development began when BioNTech founder Ugur Sahin read an article in the medical journal The Lancet that convinced him the COVID-19 coronavirus in China would soon become a global pandemic, so he called for scientists at the company to cancel their vacations and start development of a COVID-19 vaccine in January 2020. BioNTech started its program 'Project Lightspeed' to develop a vaccine against the new COVID-19 virus based on its already established mRNA-technology, which they had been developing since leading mRNA researcher Katalin Karikó joined the company in 2013. Several variants of the vaccine were created in their laboratories in Mainz, and 20 of those were presented to experts of the Paul Ehrlich Institute in Langen.

According to Pfizer, research and development for the vaccine cost close to US$1 billion.

BioNTech received a US$135 million investment from Fosun in March 2020, in exchange for 1.58 million shares in BioNTech and the future development and marketing rights of BNT162b2 in China.

In April 2020, BioNTech signed a partnership with Pfizer and received $185 million, including an equity investment of approximately $113 million.

In June 2020, BioNTech received €100 million in financing from the European Commission and European Investment Bank. The Bank's deal with BioNTech started early in the pandemic, when the Bank's staff reviewed its portfolio and came up with BioNTech as one of the companies capable of developing a COVID-19 vaccine. The European Investment Bank had already signed a first transaction with BioNTech in 2019.

In September 2020, the German government granted BioNTech €375 million for its COVID-19 vaccine development program.

Pfizer CEO Albert Bourla said he decided against taking funding from the US government's Operation Warp Speed for the development of the vaccine 'because I wanted to liberate our scientists any bureaucracy that comes with having to give reports and agree how we are going to spend the money in parallel or together, etc.' Pfizer did enter into an agreement with the US for the eventual distribution of the vaccine, as with other countries.

Clinical trials
On 4 May 2020, with four vaccine candidates entering clinical testing. The vaccine candidate BNT162b2 was chosen as the most promising among three others with similar technology developed by BioNTech. Before choosing BNT162b2, BioNTech and Pfizer had conducted Phase I trials on BNT162b1 in Germany and the United States, while Fosun performed a Phase I trial in China. In these Phase I studies, BNT162b2 was shown to have a better safety profile than the other three BioNTech candidates.

The Pivotal Phase II–III Trial with the lead vaccine candidate 'BNT162b2' began in July. Preliminary results from Phase I–II clinical trials on BNT162b2, published in October 2020, indicated potential for its safety and efficacy. During the same month, the European Medicines Agency began a periodic review of BNT162b2.

The study of BNT162b2 is a continuous-phase trial in Phase III as of November 2020. It is a 'randomized, placebo-controlled, observer-blind, dose-finding, vaccine candidate-selection, and efficacy study in healthy individuals'. The study expanded during mid-2020 to assess efficacy and safety of BNT162b2 in greater numbers of participants, reaching tens of thousands of people receiving test vaccinations in multiple countries in collaboration with Pfizer and Fosun.

The Phase III trial assesses the safety, efficacy, tolerability, and immunogenicity of BNT162b2 at a mid-dose level in three age groups: 12–15 years, 16–55 years or above 55 years. The Phase III results indicating a 95% efficacy of the developed vaccine were published on 18 November 2020. For approval in the EU, an overall vaccine efficacy of 95% was confirmed by the EMA. The EMA clarified that the second dose should be administered three weeks after the first dose.

At 14 days after dose 1, the cumulative incidence begins to diverge between the vaccinated group and the placebo group. The highest concentration of neutralizing antibodies is reached 7 days after dose 2 in younger adults and 14 days after dose 2 in older adults.

Vaccine efficacy against confirmed symptomatic COVID-19
Endpoint subgroup Efficacy
All ages 95.0%
Age 12–17 Not estimable, no cases in placebo group
Age 18–64 95.1%
Age 65–74 92.9%
Age =75 100.0%
All ages, after dose 1, before dose 2 52.4%
All ages, =10 days after dose 1, before dose 2 86.7%
All ages, <7 days after dose 2 90.5%
All ages, =7 days after dose 2 94.8%
All ages, USA 94.9%
All ages, Argentina 97.2%
All ages, Brazil 87.7%
The ongoing Phase III trial, which is scheduled to run from 2020 to 2022, is designed to assess the ability of BNT162b2 to prevent severe infection, as well as the duration of immune effect.

High antibody activity persists for at least three months after the second dose, with an estimated antibody half-life of 55 days. From these data, one study suggested that antibodies might remain detectable for around 554 days.

Preliminary results from a multinational clinical trial indicate that vaccine efficacy against symptomatic disease decreases from 96% to 84% four months after the second dose.

Specific populations
Pfizer and BioNTech started a Phase II–III randomized control trial in healthy pregnant women 18 years of age and older . The study will evaluate 30 µg of BNT162b2 or placebo administered via intramuscular injection in two doses, 21 days apart. The Phase II portion of the study will include approximately 350 pregnant women randomized 1:1 to receive BNT162b2 or placebo at 27 to 34 weeks' gestation. The Phase III portion of this study will assess the safety, tolerability, and immunogenicity of BNT162b2 or placebo among pregnant women enrolled at 24 to 34 weeks' gestation. Pfizer and BioNTech announced on 18 February 2021 that the first participants received their first dose in this trial.

A study published in March 2021, in the American Journal of Obstetrics and Gynecology came to the conclusion that messenger RNA vaccines against the novel coronavirus, such as the Pfizer-BioNTech and Moderna vaccines were safe and effective at providing immunity against infection to pregnant and breastfeeding mothers. Furthermore, they found that naturally occurring antibodies created by the mother's immune system were passed on to their children via the placenta and/or breastmilk, thus resulting in passive immunity among the child, effectively giving the child protection against the disease. The study also found that vaccine-induced immunity among the study's participants was stronger in a statistically significant way over immunity gained through recovery from a natural COVID-19 infection. In addition, the study reported that the occurrence and intensity of potential side effects in those undergoing pregnancy or lactating was very similar to those expected from non-pregnant populations, remaining generally very minor and well tolerated, mostly including injection site soreness, minor headaches, muscles aches or fatigue for a short period of time.

In January 2021, Pfizer said it had finished enrolling 2,259 children aged between 12 and 15 years to study the vaccine's safety and efficacy. On 31 March 2021, Pfizer and BioNTech announced from initial Phase III trial data that the vaccine is 100% effective for those aged 12 to 15 years of age, with trials for those younger still in progress.

A research letter published in JAMA reported that the vaccines appeared to be safe for immunosuppressed organ transplant recipients, but that the resulting antibody response was considerably poorer than in the non-immunocompromised population after only one dose. The paper admitted the limitation of only reviewing the data following the first dose of a two-dose cycle vaccine.

The United Kingdom's Medicines and Healthcare products Regulatory Agency gave the vaccine 'rapid temporary regulatory approval to address significant public health issues such as a pandemic' on 2 December 2020, which it is permitted to do under the Medicines Act 1968. It is the first COVID-19 vaccine to be approved for national use after undergoing large scale trials, and the first mRNA vaccine to be authorized for use in humans. The United Kingdom thus became the first Western country to approve a COVID-19 vaccine for national use, although the decision to fast-track the vaccine was criticised by some experts.

After the United Kingdom, the following countries and regions expedited processes to approve the Pfizer–BioNTech COVID-19 vaccine for use: Argentina, Australia, Bahrain, Canada, Chile, Costa Rica, Ecuador, Hong Kong, Iraq, Israel, Jordan, Kuwait, Malaysia, Mexico, Oman, Panama, the Philippines, Qatar, Saudi Arabia, Singapore, South Korea, the United Arab Emirates, the United States, and Vietnam.

The World Health Organization authorized it for emergency use.

In the United States, an emergency use authorization is 'a mechanism to facilitate the availability and use of medical countermeasures, including vaccines, during public health emergencies, such as the current COVID-19 pandemic', according to the FDA. Pfizer applied for EUA on 20 November 2020 and the FDA approved the application three weeks later on 11 December 2020. The United States Centers for Disease Control and Prevention Advisory Committee on Immunization Practices approved recommendations for vaccination of those aged sixteen years or older. Following the EUA issuance, BioNTech and Pfizer continued the Phase III clinical trial to finalize safety and efficacy data, leading to application for licensure of the vaccine in the United States. On 10 May 2021, the US FDA also authorized the vaccine for people aged 12 to 15 under an expanded EUA. The FDA recommendation was endorsed by the ACIP and adopted by the CDC on 12 May 2021.

On 16 February 2021, the South African Health Products Regulatory Authority in South Africa issues Section 21, Emergency Use Approval for the vaccine.

On 31 March 2021, the Turkish ministry of health gave Emergency Use Approval for the vaccine.

On 5 May 2021, Health Canada authorized the vaccine for people aged 12 to 15. On 18 May 2021, Singapore's Health Sciences Authority authorized the vaccine for people aged 12 to 15. The European Medicines Agency followed suit on 28 May 2021.

On 4 June 2021, the UK Medicines and Healthcare products Regulatory Agency came to a similar decision and approved the use of the vaccine for people twelve years of age and older.

On 19 December 2020, the Swiss Agency for Therapeutic Products approved the Pfizer–BioNTech COVID-19 vaccine for regular use, two months after receiving the application, saying the vaccine fully complied with the requirements of safety, efficacy and quality. This is the first authorization under a standard procedure.

On 21 December 2020, the Committee for Medicinal Products for Human Use of the European Medicines Agency recommended granting conditional marketing authorization for the Pfizer–BioNTech COVID-19 vaccine under the brand name Comirnaty. The recommendation was accepted by the European Commission the same day.

On 23 February 2021, the Brazilian Health Regulatory Agency approved the Pfizer–BioNTech COVID-19 vaccine under its standard marketing authorization procedure. In June 2021, the approval was extended to those aged twelve or over.

In July 2021, the U.S. Food and Drug Administration granted priority review designation for the biologics license application for the Pfizer-BioNTech COVID-19 vaccine with a goal date for the decision in January 2022. On 23 August 2021, the FDA approved the vaccine for use for those aged sixteen years and older.

The Pfizer-BioNTech Comirnaty COVID-19 vaccine was authorized in Canada on 16 September 2021, for people aged 12 and older.

On 29 July 2021, Israel's Prime Minister announced that the country was rolling out a third dose of the Pfizer-BioNTech vaccine to people over the age of 60, based on data that suggested significant waning immunity from infection over time for those with two doses. The country expanded the availability to all Israelis over the age of 12, after five months since their second shot. On 29 August 2021, Israel's coronavirus czar announced that Israelis who had not received a booster shot within six months of their second dose would lose access to the country's green pass vaccine passport.

On 18 August 2021, the United States Department of Health and Human Services announced a plan to offer a booster dose eight months after the second dose, citing evidence of reduced protection against mild and moderate disease and the possibility of reduced protection against severe disease, hospitalization, and death. Scientists and the WHO reaffirmed the lack of evidence on the need for a booster dose for healthy people and that the vaccine remains effective against severe disease months after administration. In a statement, the WHO and SAGE said that, while protection against infection may be diminished, protection against severe disease will likely be retained due to cell-mediated immunity. Research into optimal timing for boosters is still ongoing, and a booster too early may lead to less robust protection.