Summary of findings from the Phase 3 trial evaluating the Pfizer-BioNTech COVID-19 vaccine is available here. Data from this study were analyzed by the US Food and Drug Administration (FDA) before it issued an emergency use authorization for this vaccine.
Studies in Children and Adolescents
April 9, 2021: Pfizer and BioNTech submitted a request to the US Food and Drug Administration (FDA) asking that the Emergency Use Authorization (EUA) for their COVID-19 vaccine (BNT162b2) be expanded to allow the vaccine to be used for adolescents 12 to 15 years of age. As of April 27, 2021, the FDA has not scheduled a meeting of the Vaccine and Related Biological Products Advisory Committee to review this request. The FDA required this Committee to hold a public meeting to review the original EUA requests for each of the currently authorized vaccines (Pfizer/BioNTech, Moderna, and Janssen), but has not been required to meet to review EUA amendments (e.g., requests to change the number of doses contained in a vial). However, this is the first EUA amendment requesting authorization to expand age eligibility for the vaccine.
March 31, 2021: Pfizer and BioNTech announced findings from their Phase 3 clinical trial involving adolescents between the ages of 12 and 15 years. This trial enrolled 2,260 adolescents in the United States. Adolescents were randomly assigned to receive either the BTN162b2 vaccine or a placebo vaccine. Among the 1,129 adolescents who received the placebo vaccine, 18 developed COVID-19. In contrast, among the 1,131 adolescents who received the BTN162b2 vaccine, none developed COVID-19. The investigators also measured the level of SARS-CoV-2-neutralizing antibodies produced after vaccination. These antibodies protect against infection with the SARS-CoV-2 virus that causes COVID-19. On average, the level of antibodies produced was similar to that previously observed in older teens and young adults between the ages of 16 and 25 years. This provides additional confidence in vaccine efficacy. Finally, no safety concerns were identified and the side effects observed were similar to those previously reported by older teens and young adults.
The Companies also reported on the status of their global Phase 1/2/3 study that is examining the effects of the BTN162b2 vaccine among children aged 6 months to 11 years. Investigators began enrolling children between the ages of 5 and 11 years into this study during the last week of March and plan to begin enrolling younger children in April.
Updated Findings From Adult Study
April 1, 2021: Pfizer and BioNTech announced updated findings from the Phase 3 clinical trial investigating their COVID-19 vaccine, BNT162b2. Data collected through March 13, 2021 were included in the analyses. The trial included 46,307 participants. Approximately half of the participants received the BTN162b2 vaccine (2 doses administered 3 weeks apar); while the remaining participants received a placebo vaccine. A total of 927 laboratory-confirmed cases of symptomatic COVID-19 were observed. Of these, 850 cases occurred among participants who received the placebo vaccine and 77 occurred among those who received the BTN162b2 vaccine. Thus, the BTN162b2 vaccine was estimated to reduce the risk of getting COVID-19 by 91%. In other analyses, the BTN162b2 vaccine was estimated to be between 95% and 100% effective in reducing the risk of SEVERE COVID-19.
Analyses were also conducted to determine if the BTN162b2 vaccine was effective in preventing COVID-19 caused by the variant of the virus first identified in South Africa (B.1.351). A total of 800 participants were enrolled in South Africa. Nine cases of COVID-19 were observed among South African participants. All of these cases occurred in the placebo group and six were caused by the B.1.351 variant. Thus, these results suggest that the vaccine is effective in preventing COVID-19 caused by the B.1.351 variant.
Finally, these analyses included 12,000 participants who had been followed for at least six months following their second dose of the vaccine. No serious safety concerns have been observed.
Effectiveness When Used in a Nationwide Immunization Program
March 11, 2021: The Israel Ministry of Health (MoH) and BioNTech announced findings from an observational study examining the extent to which the Pfizer-BioNTech COVID-19 vaccine (BTN162b2) reduces the risk of developing COVID-19 when administered as part of a nationwide immunization program. Israel launched its national vaccination program on December 6, 2020. The program targeted individuals age 16 years or older. This target group includes about 6.4 million people. The MoH used public health surveillance data collected between January 17 and March 6, 2021 to determine the date individuals received the BTN162b2 vaccine and the results of all COVID-19 tests performed. During this time period, the BTN162b2 vaccine was the only vaccine approved in Israel for the prevention of COVID-19 and the dominant strain of the SARS-CoV-2 virus was the variant first identified in the United Kingdom (B.1.1.7).
The investigators reported that the vaccine reduced the risk of developing symptomatic COVID-19, hospitalizations, and deaths by at least 97%.
The investigators also reported that the vaccine reduced the risk of developing asymptomatic SARS-CoV-2 infection by 94%. This is important to prevent spread of the SARS-CoV-2 virus by people who are infected but who do not experience symptoms.
Finally, the investigators reported that more than 80% of the positive tests involved the B.1.1.7 variant, providing evidence that the BTN162b2 vaccine is effective against this variant as well as the original SARS-CoV-2 virus first identified in Wuhan, China.
Efficacy Against Different Strains of SARS-CoV-2
- January 20, 2021: Pfizer announced results from a recently conducted in vitro study demonstrating that the Pfizer-BioNTech vaccine, BTN162b2, is likely to be effective in preventing infection from the mutant strain of the SARS-CoV-2 virus first identified in the United Kingdom. This strain, called B.1.1.7, has caused concern because it appears to be more contagious than the original SARS-CoV-2 virus. The press release includes a link to a report describing the methods used in this study as well as study findings.
- January 19, 2021: The Norwegian Medicines Agency (NOMA) issued a statement about the 23 deaths that occurred among severely frail nursing home residents following coronavirus vaccination. The statement stresses that: “Fatal incidents among these severely frail patients following vaccination do not imply a causal relationship between COVID-19 vaccination and death.” As of January 18, 2021, 48,680 people in Norway have been vaccinated. Many of those vaccinated are nursing home residents. This group was prioritized to receive the vaccine, because nursing home residents are at greatest risk for severe COVID-19. In the statement, Dr. Sara Viksmoen Watle, Senior Physician at the Norwegian Institute of Public Health explained:
“When we vaccinate the eldest and sickest who often have several underlying conditions we expect high mortality in this population. Hence, we also expect deaths following vaccination. We do not yet know if these deaths are due to the vaccine or other causes, but we cannot exclude that common side effects may have led to a more severe course for some patients. The 23 deaths occurred within six days after vaccination. We will examine these events in relation to the expected number of deaths among the nursing home populations. The Norwegian Medicines Agency and the Norwegian Institute of Public Health are now carrying out in-depth analyses. So far, there are no statistical analyses that indicate that coronavirus vaccination has had an increased risk of death among those vaccinated.”
- January 15, 2021: The Norwegian Medicines Agency (NOMA) has advised doctors in Norway to carry out extra evaluation of very sick, elderly patients before administering the Pfizer-BioNTech vaccine. This advisory was in response to the deaths of 23 frail, elderly nursing home residents in Norway who died within 6 days of receiving the vaccine. NOMA has investigated 13 of these deaths and found that vaccine side effects such as fever and diarrhea may have contributed to the deaths. They emphasize that these types of side effects are NOT dangerous for younger, fitter people. More information can be found in: a 1-page paper published in the British Medical Journal and a NOMA report issued on January 15, 2021.
The Pfizer-BioNTech vaccine is currently the only COVID-19 vaccine approved for use in Norway and more than 20,000 doses have been administered over the past few weeks. Nursing home residents have been prioritized to receive the vaccine, because they are at greatest risk for severe COVID-19. An average of 400 nursing home residents die each week in Norway. Therefore, the reported deaths following vaccination could be coincidental. Norway is continuing to monitor reports of adverse effects following vaccination, but has not changed its vaccination strategy.
Timeline for FDA Application and Availability of Vaccine to the Public
- December 12, 2020: The Centers for Disease Control and Prevention (CDC) Advisory Committee on Immunization Practices (ACIP) will meet today to vote on recommended uses of the Pfizer-BioNTech COVID-19 vaccine candidate, BTN162b2, under the emergency use authorization (EUA) issued yesterday by the US Food and Drug Administration (FDA). The meeting is scheduled to begin at 11:00 am (EST) and adjourn at 3:00 pm (EST). The full agenda can be accessed here. The meeting is being live streamed and can be viewed here.
- December 11, 2020: The US Food and Drug Administration (FDA) issued an emergency use authorization (EUA) for the Pfizer-BioNTech COVID-19 vaccine candidate, BTN162b2. This authorization allows the vaccine to be used in individuals 16 years of age and older. As part of the EUA, Pfizer is required to submit a safety report each month that includes information about adverse events and newly identified safety concerns. If these reports are made available to the public, we will provide information from the reports on this site. The FDA Fact Sheet for healthcare providers administering the vaccine can be accessed here and a Fact Sheet for patients and caregivers can be accessed here.
- December 10, 2020: The US Food and Drug Administration (FDA) Vaccines and Related Biological Products Advisory Committee (VRBPAC) recommended that an emergency use authorization be issued for the Pfizer-BioNtech candidate vaccine, BNT162b2. The committee voted on the following question: “Based on the totality of scientific evidence available, do the benefits of the Pfizer-BioNTech COVID-19 Vaccine outweigh its risks for use in individuals 16 years of age and older?” The vote was 17-Yes, 4-No, and 1-Abstention. Those who voted No were concerned that there is limited information available for use of the vaccine in adolescents age 16 and 17. It is likely that the FDA will issue the EUA within the next few days.
- December 8, 2020: The US Food and Drug Administration (FDA) has released detailed findings from the Phase 3 trial of the Pfizer-BioNtech candidate vaccine, BNT162b2. A 92-page document prepared by Pfizer is available here. A 53-page document prepared by the FDA is available here. On page 11 of this document the FDA states: “As such, FDA has determined that the Sponsor has provided adequate information to ensure the vaccine’s quality and consistency for authorization of the product under an EUA” (Emergency Use Authorization). On page 12, the FDA states that the vaccine is proposed “for active immunization for the prevention of COVID-19 caused by SARS-CoV-2 in individuals 16 years of age and older.” We plan to report summarized safety and efficacy findings for the full sample and for different subgroups (based on age, gender, race, country) within the next few days.
- November 20, 2020: Pfizer announced that it plans to submit a request to the US Food and Drug Administration (FDA) today for an Emergency Use Authorization (EUA) for its candidate vaccine, BNT162b2. If the FDA approves the EUA, the company said that it may be possible to start vaccinating high-risk people in the US by the middle to end of December 2020. The FDA has stated previously that it plans to have an open meeting of the FDA’s Vaccines and Related Biological Products Advisory Committee (VRBPAC) before approving a EUA for any COVID-19 vaccines. This committee meeting is planned for Dec. 10, 2020. The FDA plans to make background materials for this meeting available on December 8, 2020. We anticipate that these materials will include much more detailed findings from the Phase 3 study testing BNT162b2. In addition, the Centers for Disease Control and Prevention (CDC) has scheduled a meeting for its Advisory Committee on Immunization Practices (AICP) on November 23, 2020. This Committee develops recommendations for the use of vaccines in the US. However, it does not have the authority to issue a EUA.
- November 9, 2020: Pfizer announced that it expects to submit for an Emergency Use Authorization (EUA) for their mRNA-based COVID-19 vaccine candidate, BNT162b2, from the Food and Drug Administration (FDA) in the third week of November. This is based on when they expect to have two months of follow-up safety data for at least 15,000 study participants, as required by the FDA.
- November 9, 2020: Pfizer currently expects to manufacture up to 50 million vaccine doses for the global market by the end of 2020 and up to 1.3 billion doses by the end of 2021. This assumes that the vaccine is approved for marketing by regulatory agencies (such as the Food and Drug Administration (FDA) in the US and the European Medicines Agency (EMA) in Europe).
- October 19, 2020: According to the Pfizer COVID-19 website, the company expects to manufacture 100 million vaccine doses for the global market by the end of 2020 and up to 1.3 billion doses by the end of 2021. This assumes that the vaccine is approved for marketing by regulatory agencies (such as the Food and Drug Administration (FDA) in the US and the European Medicines Agency (EMA) in Europe).
- October 16, 2020: In an open letter, Pfizer Chairman and CEO Albert Bourla announced that Pfizer may know whether their vaccine is effective by the end of October. The exact date is uncertain because the data from the study will not be analyzed until 32 study participants have gotten laboratory confirmed symptomatic COVID-19. According to the study protocol, the vaccine would be considered effective if at least 26 of these 32 participants were in the control group.
Milestones to Reach Before FDA Submission
Expected Date When Milestone Will Be Reached
32 study participants must develop laboratory-confirmed, symptomatic COVID-19.
At least 26 of these 32 people (81%) must be in the control group (that is, they received a placebo vaccine).
At least 15,000 study participants (50%) must be followed for at least 8 weeks after receiving their second dose of vaccine to assess possible side effects.
Manufacturing data must demonstrate the quality and consistency of the vaccine production process.
Before the Third Week of November
Vaccine Authorized for Use in the UK
- December 2, 2020: The Commission on Human Medicines (CHM) in the United Kingdom (UK) approved emergency use of Pfizer’s vaccine candidate, BNT162b2, following review by the Medicines and Healthcare products Regulatory Agency (MHRA). The CHM also released a document for health care providers in the UK that contains information from clinical trials testing BNT162b2. As reported previously, among study participants who were age 16 or older, a total of 170 developed laboratory-confirmed symptomatic COVID-19. Of these 170 study participants, 162 had received the placebo vaccine and 8 had received BNT162b2. Thus, the vaccine appears to reduce the risk of getting COVID-19 by 95.0% (95% confidence interval 90.3% to 97.6%). The vaccine appears to be equally effective in adults age 65 and older, who made up 21.8% of the sample. However, it is not clear if people over the age of 85 were enrolled in the study. (By study design, only cases of COVID-19 that occurred at least 7 days following receipt of the second vaccine dose were counted. This allowed time for immunity to develop following vaccine administration.)
Safety data are based on 19,067 study participants (9,531 who received the BNT162b2 vaccine and 9,536 who received the placebo vaccine). The most common side effects were: pain at the injection site (> 80%), fatigue (> 60%), headache (> 50%), muscle pain (> 30%), chills (> 30%), joint pain (> 20%), and fever (> 10%). The intensity of these side effects was usually mild or moderate and resolved within a few days after having the vaccine administered.
- Pregnancy, Breast-feeding: Due to the lack of data, it was originally recommended that the BNT162b2 vaccine not be administered during pregnancy. However, this recommendation was changed. The current professional labeling states that use of this vaccine during pregnancy “should only be considered when the potential benefits outweigh any potential risks for the mother and foetus.”
- Children: Data have only been reported for study participants who were age 16 or older. The vaccine is currently being studied in children age 12-16, so more data may be released soon.
- Duration of Immunity: We also do not know how long protection from COVID-19 will last after BNT162b2 is administered.
Results from Primary Efficacy Analyses
- November 20, 2020: Pfizer submitted materials to the US Food and Drug Administration requesting an emergency use authorization for it COVID-19 vaccine candidate, BNT162b2. The FDA announced that the materials will be reviewed by its Vaccines and Related Biological Products Advisory Committee (VRBPAC) on December 10, 2020. This meeting will be live streamed on the agency’s YouTube, Facebook and Twitter channels. The FDA plans to make background materials for this meeting available on December 8, 2020. We anticipate that these materials will include much more detailed findings from the Phase 3 study testing BNT162b2.
- November 18, 2020: Pfizer announced that it has completed the primary efficacy analyses of data from the Phase 3 study testing its COVID-19 vaccine candidate, BNT162b2. As planned before the start of data collection, the primary efficacy analyses were conducted after 164 study participants developed laboratory confirmed symptomatic COVID-19. The company reported that a total of 170 people had reached this study endpoint. Of these, 162 had received the placebo vaccine and 8 had received the BNT162b2 vaccine. Thus, they estimated that the vaccine is 95% effective in preventing COVID-19. The vaccine also appears to help prevent severe COVID-19. A total of 10 people in the study developed severe COVID-19. Of these, 9 had received the placebo vaccine. The company reported no serious safety concerns. The most common “severe” side-effects reported were: fatigue (3.8%) and headache (2%). A “severe” side effect was defined as one that prevented a participant from doing routine daily activities on at least one day following an injection. Finally, the company reported that the findings were similar across groups that differed in age, gender, race, and ethnicity. Although these findings are very promising, several important questions remain. For example, we do not know if the vaccine reduces the risk of hospitalization or death. We also do not know if the vaccine prevents asymptomatic COVID-19. This is important because individuals with asymptomatic COVID-19 can infect others who can then develop more serious disease. We also do not know how long protection lasts and only limited data are available concerning side-effects the vaccine may have. Finally, data reported by the company still needs to be reviewed by experts who are not involved with the study
- November 9, 2020: Pfizer announced that its mRNA-based COVID-19 vaccine candidate, BNT162b2, has demonstrated over 90% efficacy in preventing laboratory-confirmed symptomatic COVID-19 among participants with no prior history of SARS-CoV-2 infection. These results are based on planned interim analyses. A total of 94 study participants have developed laboratory-confirmed, symptomatic COVID-19 to date. (Cases of COVID-19 are only counted if they occurred at least one week after the second dose of the vaccine was administered. This gives the vaccine time to work.) The company reported that no serious safety concerns have been observed in the trial. We will provide more detailed information as soon as it is available to the public. The company will conduct their final efficacy analyses when at least 164 study participants have developed laboratory confirmed cases of COVID-19. The company also plans to conduct analyses to see if the vaccine helps prevent severe COVID-19. Although these findings are very promising, several important questions remain. For example, we do not know if the vaccine reduces the risk of severe COVID-19, hospitalization, or death. We also do not know if the vaccine prevents asymptomatic COVID-19. This is important because individuals with asymptomatic COVID-19 can infect others who can then develop more serious disease. We also do not know how long protection lasts and only limited data are available concerning side-effects the vaccine may have. Finally, data reported by the company still needs to be reviewed by experts who are not involved with the study.
- November 9, 2020: Pfizer announced that the trial of their mRNA-based COVID-19 vaccine candidate, BNT162b2, has enrolled 43,538 participants and 38,955 have received the second dose of the vaccine, which is given three weeks after the first dose. About 30% of participants recruited in the United States have racially and ethnically diverse backgrounds. The Pfizer COVID-19 vaccine website provides more information about the race/ethnicity of study participants and the percentage of participants between the ages of 56 and 85 years.
- October 19, 2020: According to the Pfizer COVID-19 vaccine website, they have enrolled 39,862 study participants in their clinical trial to date and 34,601 of these participants have received the second dose of vaccine. (Note: The vaccine being tested in this study requires 2 doses, given 3 weeks apart.) The Pfizer COVID-19 vaccine website includes a table showing the race/ethnicity of study participants and the percentage of participants between the ages of 56 and 85 years.
- October 13, 2020: Pfizer announced that it has gotten approval from the Food and Drug Administration (FDA) to enroll children as young as 12 years old in their clinical trial.
- September 12, 2020: Pfizer announced that it plans to increase enrollment in their clinical trial from about 30,000 study participants up to about 44,000 participants. They also plan to expand the eligibility criteria for the study to include adolescents who are 16 or 17 years old.
Around the World
- November 20, 2020: Pfizer announced that several countries have started a rolling review of its vaccine candidate, BNT162b2. These include: Australia, Canada, Japan, the European Union, and the United Kingdom.
- October 6, 2020: The European Medicines Agency (EMA) announced that it had started a “rolling review” of data from studies involving Pfizer’s vaccine candidate, BNT162b2. The EMA is the equivalent of the Food and Drug Administration in the United States. According to the EMA announcement, “A rolling review is one of the regulatory tools that EMA uses to speed up the assessment of a promising medicine or vaccine during a public health emergency. Normally, all data on a medicine’s effectiveness, safety and quality and all required documents must be submitted at the start of the evaluation in a formal application for marketing authorisation. In the case of a rolling review, EMA’s human medicines committee (CHMP) reviews data as they become available from ongoing studies, before a formal application is submitted. Once the CHMP decides that sufficient data are available, the formal application should be submitted by the company. By reviewing the data as they become available, the CHMP can reach its opinion sooner on whether or not the medicine or vaccine should be authorised.”