pfizer–biontech covid-19 vaccine pfizer–biontech covid-19 vaccine the pfizer–biontech covid-19 vaccine (inn: tozinameran), sold under the brand name comirnaty, is an mrna-based covid-19 vaccine developed by the german biotechnology company biontech. for its development, biontech collaborated with american company pfizer to carry out clinical trials, logistics, and manufacturing. it is authorized for use in people 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 (modrna) 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. pfizer–biontech covid-19 vaccineinn: tozinamerana vial of the pfizer–biontech covid‑19 vaccine for the u.s. marketvaccine descriptiontargetsars-cov-2vaccine typemrnaclinical datapronunciationtozinameran: /ˌtoʊzɪˈnæmərən/ toh-zih-nam-ər-ən trade namescomirnatyother namesbnt162b2, covid-19 mrna vaccine (nucleoside-modified), covid-19 vaccine (mrna)ahfs/drugs.commultum consumer informationmedlineplusa621003license data eu ema: by inn us dailymed: tozinameran pregnancycategory au: b1 routes ofadministrationintramuscularatc codej07bx03 (who) legal statuslegal status au: s4 (prescription only) br: approved ca: rx-only / schedule d uk: conditional marketing authorization granted us: ℞-only with standing order; approved for those aged 12+; emergency use authorization for those aged 6 months–11 years eu: marketing authorization granted ch: rx-only za: section 21 full list of pfizer-biontech vaccine authorizationsidentifierscas number2417899-77-3pubchem sid434370509drugbankdb15696unii5085zfp6sjkeggd11971chemblchembl4650429 part of a series on thecovid-19 pandemicscientifically accurate atomic model of the external structure of sars-cov-2. each "ball" is an atom. covid-19 (disease) sars-cov-2 (virus) cases deaths timeline 2019 2020 january responses february responses march responses april responses may responses june responses july responses august responses september responses october responses november responses december responses 2021 january responses february responses march responses april responses may responses june responses july responses august responses september responses october responses november responses december responses 2022 january responses february responses march responses april responses may responses june responses july responses august responses september responses october responses november december 2023 january february march april may locations by country and territory africa antarctica asia europe north america oceania south america by conveyance cruise ships naval ships international response endemic phase evacuations face masks international aid investigations into origin lockdowns by country misinformation by governments fake treatments social distancing software travel united nations world health organization wto ip waiver undercounting of deaths covid-19 apps zero-covid national responses africa china european union germany ghana india ireland netherlands new zealand nigeria philippines russia sweden uk government us federal government vietnam medical response disease testing breathalyzer development drug development drug repurposing public health mitigation vaccines history research vitt deployment authorizations operation warp speed misinformation and hesitancy us vaccine card vaccine passports current vaccines coronavac covaxin convidecia janssen medigen moderna novavax oxford–astrazeneca pfizer–biontech sinopharm bibp sputnik v variants variants of concern alpha beta gamma delta omicron other variants epsilon zeta eta theta iota kappa lambda mu cluster 5 lineage b.1.617 economic impact and recession arts and culture aviation cannabis cinema films disney fashion financial markets food industry food security journalism music performing arts retail shipping television us sportscasting programs tourism video games by country canada india ireland malaysia new zealand russia uk us by sport association football baseball basketball combat sports cricket disc golf gaelic games gridiron football ice hockey motorsport rugby league impacts animals black people crime death rates by country disability domestic violence emergency evacuations education female environment hospitals language lgbt community long-term care media coverage mental health symptoms migration military notable deaths other health issues politics diplomacy popular culture protests pregnancy prisons religion catholic church hajj science and technology social media strikes suicides telehealth xenophobia and racism society ireland malaysia new zealand russia uk us covid-19 portal 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 and no serious safety concerns. most side effects are mild to moderate in severity and are gone within a few days. the most common include mild to moderate pain at the injection site, fatigue, and headaches. reports of serious side effects, such as allergic reactions, are very rare and no long-term complications have been reported. 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 (fda). distribution and storage is a logistical challenge because the vaccine needs to be stored at extremely low temperatures. in august 2022, a bivalent version of the vaccine (pfizer-biontech covid-19 vaccine, bivalent) was authorized for use as a booster dose in individuals twelve years of age and older in the united states. in september 2022, the ba.1 version of the bivalent vaccine (comirnaty original/omicron ba.1 or tozinameran/riltozinameran) was authorized as a booster for use in the united kingdom. in september 2022, the european union authorized both the ba.1 and the ba.4/ba.5 (tozinameran/famtozinameran) booster versions of the bivalent vaccine. 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 (who) 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. a third, fourth, or fifth dose can be added in some countries. effectiveness a test-negative case-control study published in august 2021, found that two doses of the bnt162b2 (pfizer) vaccine had 93.7% effectiveness against symptomatic disease caused by the alpha (b.1.1.7) variant and 88.0% effectiveness against symptomatic disease caused by the delta (b.1.617.2) 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 u.s. centers for disease control and prevention (cdc) published a study reporting that the effectiveness against infection decreased from 91% (81–96%) to 66% (26–84%) 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. initial effectiveness by variant doses severity of illness alpha beta gamma delta omicron others circulating previously 1 asymptomatic 38% (29–45%) 17% (10–23%) not reported 30% (17–41%) not reported 60% (53–66%) symptomatic 27% (13–39%) 43% (22–59%) 33% (15–47%) not reported 66% (57–73%) hospitalization 83% (62–93%) 0% (0–19%) 56% (−9 to 82%) 94% (46–99%) not reported 78% (61–91%) 2 asymptomatic 92% (90–93%) 75% (71–79%) not reported 79% (75–82%) not reported 92% (88–95%) symptomatic 92% (88–94%) 88% (61–96%) 83% (78–87%) 88% (66–96%) 94% (87–98%) hospitalization 95% (78–99%) 100% (74–100%) 100% 96% (86–99%) 70% (62–76%) 87% (55–100%) 3 symptomatic not reported not reported not reported 96% (89–99%) 76% (56–86%) not reported surveillance study from 20 december 2020 to 1 february 2021 in israel. during this period, according to nextstrain, the dominant variant in israel was lineage b.1.1.50 and the alpha variant was becoming dominant. preliminary data of effectiveness against hospitalization referenced by public health england. effectiveness drops to 49% (24–65%) in weeks 10–14 after the second dose and then stabilizes at 34%–37% thereafter. a confidence interval was not provided, so it is not possible to know the accuracy of this measurement. booster dose. efficacy data from a study with more than 10,000 participants. effectiveness drops to about 45% 10 weeks after the booster dose. on 12 november, public health england reported a possible but extremely small reduction in effectiveness against symptomatic disease from the delta sublineage ay.4.2 at longer intervals after the second dose. preliminary data suggest that the effectiveness against the omicron variant starts to decline in about 10 weeks, either after the initial two-dose regimen or after the booster dose. for other variants, the effectiveness of the initial doses starts to decline in about six months. a case-control study in qatar from 1 january to 5 september 2021 found that effectiveness against infection peaked at 78% (95% ci, 76–79%) in the first month after the second dose, followed by a slow decline that accelerated after the fourth month, reaching 20% at months 5 to 7. a similar trajectory was observed against symptomatic disease and against specific variants. effectiveness against severe disease, hospitalization and death was more robust, peaking at 96% (93–98%) in the second month and remaining almost stable through the sixth month, declining thereafter. on 21 october, a phase 3 trial showed that a booster dose given approximately 11 months after the second dose restored the protective effect to the 96% (95% ci, 89–99%) efficacy level against symptomatic disease from the delta variant. on 8 december, pfizer and biontech reported that preliminary data indicated that a third dose of the vaccine would provide a similar level of neutralizing antibodies against the omicron variant as seen after two doses against other variants. on 14 december, private health insurer discovery health, in collaboration with the south african medical research council, reported that real-world data from more than 211,000 cases of covid-19 in south africa, of which 78,000 were of the omicron variant, indicate that effectiveness against the variant after two doses is about 70% against hospital admission and 33% against symptomatic disease. protection against hospital admission is maintained for all ages and groups with comorbidities. a study of the bivalent booster effectiveness against severe covid-19 outcomes in finland, september 2022–january 2023, has shown that it reduced the risk of severe covid-19 outcomes among the elderly. by contrast, among the chronically-ill 18–64-year-olds the risk was similar among those who received bivalent vaccine and those who did not. among the elderly a bivalent booster provided highest protection during the first two months after vaccination, but thereafter signs of waning were observed. the effectiveness among individuals aged 65–79 years and those aged 80 years or more was similar. specific populations based on the results of a preliminary study, the u.s. centers for disease control and prevention (cdc) recommends that pregnant women get vaccinated with the covid‑19 vaccine. a statement by the british medicines and healthcare products regulatory agency (mhra) and the commission on human medicines (chm) 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 ten 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 (nsw health) in australia found that the pfizer-biontech vaccine is safe for those with 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 (alongside that of moderna and