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Living Evidence - COVID-19 vaccines

Living evidence tables provide high level summaries of key studies and evidence on a particular topic, and links to sources. They are reviewed daily and updated as new evidence and information is published.

There are four main types of vaccines and over 200 candidate vaccines in development. This table includes information on vaccines that have published phase 3 trial data in the peer reviewed literature. It focuses on information related to efficacy, safety and rollout.

 Pfizer/BioNTech BNT162b2Oxford/AstraZeneca AZD1222Moderna mRNA-1273 Sputnik V Gam-COVID-VacJohnson & Johnson Ad26.COV2.S

Phase 3 trial publication

The New England Journal of Medicine (1)

The New England Journal of Medicine (2)

The Lancet (3)

The Lancet (4)

The New England Journal of Medicine

The Lancet

The Lancet

Vaccine type

mRNA (nucleic acid)

Viral vector

mRNA (nucleic acid)

Viral vector

Viral vector

Dosing schedule from phase 3 trial

Two 30µg doses;

Dose interval 21 days

Two doses (5x1010viral particles);

Dose interval 28 days

Two 100µg doses;

Dose interval 28 days

Two doses (1011 viral particles);

Dose interval 21 days

One dose (5x1010 viral particles)

Efficacy - various endpoints

     

SARS-CoV-2 infection

14 to 20 days after Dose 1: 46%*
≥7 days after Dose 2: 92%* (2)

55.7%* (3)

54.1%* (4)

89.6%*

Not yet available

Not yet available

Asymptomatic infection

14 to 20 days after Dose 1: 29% (estimated)*

≥7 days after Dose 2: 90% (estimated)* (2)

LD/SD (initial half dose) 58.9% /SD/SD (full dose) recipients 3.8%
Total combined 27.3%*ꝉ (3)

COV002 UK study participants only: LD/SD 49.3%* / SD/SD 2.0%*
Total combined 22.2%* (4)

Not yet available

Not yet available

At day 71 days: 65.5%*

Severe COVID-19

88.9% after Dose 1* (1)

14 to 20 days after Dose 1: 62%*
≥7 days after Dose 2: 92%* (2)

For hospitalisation:
14 to 20 days after Dose 1: 74%*
≥7 days after Dose 2: 87%* (2)

100%*ⱶ (3)

100% (US Phase 3 trial; 2 Doses administered 4 weeks apart)^

100%*

100%*

≥14 days after dose: 76.7%

≥28 days after dose: 85.4%

For hospitalisation:
≥14 days after dose: 93.1%*
≥28 days after dose: 100%*

Mortality

14 to 20 days after Dose 1: 72% (estimated)* (2)

Not yet available

Not yet available

Not yet available

Not yet available

Transmissionⱡ

Not yet available. 

Overall reduction in any PCR+ was 54.1% indicating the potential for a reduction of transmission with a regimen of two SDs.*^ (4)

Not yet available

Not yet available

Not yet available

Effectiveness ('real world' data)

Symptomatic/infection

The CDC reports low rate of new infections vaccinated people (approx.. 5800 of 77 million).^

In general population, range from 85% to 92.8% effective after dose 2; 42% to 70% effective after dose 1.^*

Multiple studies in healthcare workers across different jurisdictions show reduction in infections after one or two doses. Range from 86% to 100% effective 7 days after dose 2.*^

Multiple studies on older adults ≥60 years across different jurisdictions show reduced positive cases ranging from 52 - 85%.^ People ≥80 years may produce lower immune response to vaccine than people <60 years.*

Multiple studies show prior infection has protective effects against new infection and severe outcomes, including death.^

Asymptomatic

Multiple studies show significantly reduced risk in vaccinated adults and healthcare workers.

Hospitalisation

Multiple studies show effective at preventing hospitalisation, ranging from 71% to 97%.^

Mortality

Multiple studies show effective at preventing deaths, ranging from 85% to 98.7%.^ mRNA vaccines 64.2% effective for partially vaccinated individuals.^

Transmission

Vaccination of health care workers was associated with a substantial reduction of cases in household contacts.^

Risk of household transmission 49% lower if index cases vaccinated ≥21 days prior to testing positive (compared to no vaccination).^

Symptomatic/infection

Multiple studies show reduced infections, 65% to 73% after dose 1 and no symptomatic infection in healthcare workers after dose 2.

Prior infection has protective effects against new infection.^

Hospitalisation

Multiple studies show effective at preventing hospitalisation, ranging from 80% to 94%.*^

Transmission

Vaccination of health care workers was associated with a substantial reduction of cases in household contacts.^

Risk of household transmission 38% lower if index cases vaccinated ≥21 days prior to testing positive (compared to no vaccination).^

Symptomatic/infection

The CDC reports low rate of new infections vaccinated people (approx.. 5800 of 77 million).^

In US healthcare workers:
91.2% effective >14 days after Dose 1;
98.6% effective >14 days after Dose 2.*

Immune response to the vaccination is higher in previously infected or exposed individuals  .^

Asymptomatic

Significantly reduced risk in vaccinated adults.*

Hospitalisation

Significantly lower 14-day hospital admission rates than unvaccinated individuals.^ mRNA vaccines 96% effective at preventing hospitalisation; 77% for partially vaccinated individuals.^

Mortality

mRNA vaccines 98.7% effective at preventing deaths; 64.2% effective for partially vaccinated individuals.^

Not yet available

Symptomatic/Infection

76.7% effectiveness against infection >14 days after vaccination*^

Hospitalisation

Relative risk of 14-Day Hospital admission rate: 0.68*^

Relative risk of 14-Day ICU admission rate: 0*^

Mortality

Relative risk of 14-Day Mortality rate: 0 (n=1)*^

Safety

Initial assessment determined acceptable safety profile.

TGA safety data collected on the COVID-19 vaccines used in Australia is consistent with the known side effects. No new safety concerns have been identified.

Reports of anaphylaxis (4.7 cases per 1 million vaccinations).*^

Extremely rare cases of immune thrombocytopenia (<1 case per million).^ Rare reports of cerebral venous sinus thrombosis (CVST).^ Risk of cerebral blood clots from COVID-19 is 10 times that from vaccination.^

Some evidence of delayed-type hypersensitivity reactions lasting <8 hours to ≥72 hours.*^

Case reports of Facial paralysis, Chilblain-like legions, Herpes zoster,  Flare of biopsy-proven, erythema multiforme, Pityriasis rosea-like eruption, Leukocytoclastic vasculitis flare , Gross hematuria in patients with IgA nephropathy, Acute rejection of kidney transplant  , Varicella-zoster virus reactivation, Ischaemic stroke.*^

Initial assessment determined acceptable safety profile.

TGA safety data collected on the COVID-19 vaccines used in Australia is consistent with the known side effects.

TGA has found no evidence of increased risk by anaphylaxis.^

Reports of blood clots and one death.^ 169 cases reported by the EMA (Europe) and 79 cases reviewed by the MHRA (UK). Eleven reports of thrombosis with thrombocytopenia in Australia, aged 35 to 80 years. TGA reports they are likely linked to vaccination.^ Multiple studies suggest resemblance to heparin induced thrombocytopenia.^

European Medicines Agency concludes unusual blood clots with low blood platelets should be listed as very rare side effects, and reaffirms benefits outweigh the risks, increasing with age and infection rate. Most cases in women under 60 years of age within 2 weeks of vaccination. However, TGA notes that an association with gender has not been firmly established. Overall benefit-risk remains positive, especially in those age 50 and older.^

Case reports of Myelitis, Fatal cerebral haemorrhage, Deep vein thrombosis, Immune thrombocytopenic purpura, Cerebral venous thrombosis, Ischaemic stroke.*^

Initial assessment determined acceptable safety profile.

Reports of anaphylaxis (2.5 cases per 1 million vaccinations).*^

Extremely rare cases of immune thrombocytopenia (<1 case per million).^ Rare reports of cerebral venous sinus thrombosis (CVST); no significant link with vaccine.^ Risk of cerebral blood clots from COVID-19 is 10 times that from vaccination.^

Some evidence of delayed-type or T-cell–mediated hypersensitivity on or after day 8 post first dose.*

Case reports of Chilblains, Facial paralysis, FDG-avid benign, reactive lymph nodes in cancer patient, Gross hematuria in patients with IgA nephropathy.*^

Initial assessment determined acceptable safety profile.

Initial assessment determined acceptable safety profile.

Six possible cases of CVST. EMA investigation reports that unusual blood clots are a “very rare side effect” of the vaccine and confirms positive overall benefit-risk. CDC concludes that benefits of resuming vaccination outweighs risks.^

Specific populations

Children

Aged 12-15: 100% efficacy and robust antibody responses^

Aged 6months -11 years: trial underway^

Immunocompromised people

Multiple studies of effectiveness with few serious adverse events.^* Higher response elicited in those with prior infection.^

However, compared to healthy controls, multiple studies show weaker antibody response and higher rate of infection after single and double doses.*

Pregnant and lactating women

Similar immune response in vaccinated pregnant and lactating women compared to vaccinated non-pregnant women.

No obvious safety signals in pregnancy or neonatal outcomes, especially in women vaccinated during third trimester*

Maternal antibody production 5 days after dose 1, transplacental transfer of immunity to neonate 16 days after dose 1.*

Aged care residents

Lower incidence of infections, symptomatic illness, hospitalisations, and death following vaccination* Report of few breakthrough infections in full vaccinated individuals, most with asymptomatic illness.*

Children

Aged 6-17: trial underway^

Immunocompromised people

Weaker antibody response compared to non-immunocompromised individuals, especially after single dose.*

Aged care residents

Single dose led to protection against asymptomatic infection for up to 7 weeks.^

Children

Aged 6months to 12 years: trial underway^

Immunocompromised people

Weaker antibody response compared to healthy controls^ Higher antibody response elicited in those with prior infection.^

Pregnant and lactating women

Similar immune response in vaccinated pregnant and lactating women compared to vaccinated non-pregnant women.

No obvious safety signals in pregnancy or neonatal outcomes, especially in women vaccinated during third trimester*

Maternal antibody production 5 days after dose 1, transplacental transfer of immunity to neonate 16 days after dose 1.*

Aged care residents

Lower incidence of infections, symptomatic illness, hospitalisations, and death following vaccination* Report of few breakthrough infections in full vaccinated individuals, most with asymptomatic illness.*

Not yet availableNot yet available

Single dose protection*

52.4%

Multiple studies reporting on single dose,  reduction in positive cases ranging from 30% to 75%.

73%*^

Multiple studies reporting on single dose,  reduction in positive cases ranging from 64% to 76%.^ (4)

95.2%*

Single dose may be insufficient to neutralise B.1.351 variant in previously uninfected individuals.^

73·6% from 15 to 21 days after first dose*

Single dose in previously infected individuals elicits a higher antibody response than two doses in uninfected individuals.^

See efficacy above (dosing schedule is single dose)

Extended dosing schedule

Gaps between doses should not exceed 42 days*^

A pre peer-reviewed study showed vaccine was effective from day 11 after single dose; then no detectable increase in efficacy following the second vaccination.^

Multiple studies showed increased immunogenicity or seroconversion after second dose in immunocompromised people supporting early or non-delayed second doses.*

53.4% at <6-week interval between doses and 65.4% at ≥6-week interval (3)

After the second dose, efficacy was higher with a longer prime-boost interval: VE 81.3% at 12+ weeks, compared with VE 55.1% at <6 weeks.*^ (4)

Seroconversion after second dose in immunocompromised individuals supporting non-delayed second dose.*

Not yet available

Not yet available

Not applicable

Jurisdictional policy on timing of second doses

UK delaying second dose until 12 weeks after first dose*^

Planned roll-out in the UK is administration of two doses, 12 weeks apart*^ (4)

Drawing on advice from the TGA, ATAGI in Australia recommends the vaccine be administered 12 weeks apart.^

Not yet available

Not yet available

Not applicable

Prior COVID-19 infection

Following a single dose, prior infection to SARS-CoV-2 led to a boost response upon vaccination (IgG titres ~one order of magnitude higher than in those without prior infection), and a greater humoral response than uninfected individuals who received a second dose.

Not yet available

Not yet available

Not yet available

Not yet available

Longevity of protection

Not yet available

Generally, adenoviruses are highly immunogenic, driving long-lasting immune responses*^

Likely to offer protection for a “couple of years”, as antibody decay is very slow.*^

Antibodies persisted through 6 months after the second dose.

Generally, adenoviruses are highly immunogenic, driving long-lasting immune responses*^

Generally, adenoviruses are highly immunogenic, driving long-lasting immune responses*^

Impact of new variants on vaccines

Multiple studies show effective at neutralising B.1.1.7*^. Reduction in neutralising capacity against B.1.1.7 carrying the E484K mutation.^ Breakthrough infection with B.1.1.7 and B.1.351 variant in partially vaccinated individuals.^

Multiple studies show significant reduction in neutralisation of B.1.351.*^

Reports of vaccine booster to target B.1.351 variant.^

Significant reduction in neutralisation by P.2 and P.1 variants.

Single and double dose boosted neutralising titres against all variants of concern in previously infected individuals, compared to noninfected individuals.*^

As little as 10.4% protection against mild to moderate disease for the B.1.351 variant,*^ while WHO suggests vaccine ability to protect against severe COVID-19.^

Reports of 74.6% efficacy for B.1.1.7.*^

Single dose boosted neutralising titres against all variants of concernin previously infected individuals.*

Multiple studies show effective at neutralising B.1.1.7 variant.*^

Effective however sixfold reduction in level of neutralising titres to the B.1.351 variant.*^ However most individuals neutralize the SARS-CoV-2 B.1.351 variant suggesting protective immunity is retained.*

Significant reduction in neutralisation by P.2 and P.1  variants.

2 to 2.5 times less sensitive to neutralization of B.1.429 (Californian) variant. Protective immunity is retained.

Reduced neutralisation capacity against B.1.351 variant, and to a lesser extent variants carrying E484K mutation, but not against B.1.1.7.^

(94.5% of South African trial arm had B.1.351 variant):

For moderate to severe disease:

≥14 days after dose: 52.0%

≥28 days after dose: 64.0%

For severe to critical disease:

≥14 days after dose: 73.1%

≥28 days after dose: 81.7%

Storage

-80°C and -60°C


A storage condition of  -20±5°C for up to 2 weeks within the shelf life when stored at -90 to -60°C, and storage of unopened vials for up to 5 days at domestic refrigerator temperatures (2°C to 8°C) has been approved in Australia.^

2°C to 8°C

-25°C and -15°C

-18°C (liquid, used in trial) and 2–8°C (freeze dried, approved by Ministry of Health of the Russian Federation)

2°C to 8°C

Study participants

43,548 enrolled, 43,448 received injections (randomly assigned 1:1 ratio) (1)

596,618 vaccine recipients matched 1:1 ratio to controls on variables associated with the probability of both vaccination and infection or severity of COVID-19. (2)

23 848 enrolled, 11 636 included in interim primary efficacy analysis (randomly assigned 1:1 ratio) (3)

17178 participants included in the efficacy analysis after a further month of data collection from original Lancet article* (4)

30,420 enrolled (randomly assigned 1:1 ratio)

21,977 enrolled, 19,866 included in primary outcome analysis (randomly assigned 3:1 ratio)

44,325 enrolled, 43,783 received vaccine or placebo (randomly assigned 1:1 ratio)

Study population

49% female, 35% obese, 21% at least one coexisting condition. Majority Caucasian (83%). Median age 52 years; 42% older than 55y (1)

Participants from Clalit Health Services data, the largest of four integrated health care organizations in Israel, which insures 4.7 million patients (53% of the population). (2)

Majority aged 18–55 years (86.7% in UK; 89.9% in Brazil cohort). 60.5% female. Majority Caucasian (91.4% in UK; 66.6% in Brazil)

47.3% female, mean age 51.4 years; 24.8% were 65 years of age or older. Majority Caucasian (79.2%)

38.8% female, mean age 45.3 years; 10.8% were 60 years of age or older. Majority Caucasian (98.5%)

45.0% female, median age 52 years; 33.5% were 60 years of age or older. Majority Caucasian (58.7%).

Latin America 40.9%; South Africa 15.0%; US 44.1%

Authorisation granted in Australia

Yes

Yes

No

No No

Number of jurisdictions authorisation granted

58 plus EU and WHO^

98 plus EU and WHO^



Rollout halted in South Africa (7 February 2021)^ who are currently evaluating a stepwise rollout, assessing impact on hospitalisation rates in the first 100,000 people.^

Several EU countries to resume rollout as EMA review confirms acceptable safety profile. This is after rollout was initially suspended in at least 24 countries due to reports of blood clots and one death.^

In Australia, ATAGI recommends that the Pfizer vaccine is preferred over AstraZeneca in adults aged under 50 years. Germany approve vaccine for all ages after they initially suspended used in people younger than 60.Canada suspend use in people younger than 40, due to concerns of rare blood clots.^ While UK Government say it is preferred people under 30 years be offered an alternative vaccination.

20 plus EU^57^

19 plus EU and WHO^

After suspending rollout to investigate reports of blood clots, rollout resumed in the EU, Norway and Iceland with updated EMA and Healthcare Professionals guidance. US regulators have also resumed rollout.

Phase 3 trials reported in the grey literature  / press releases

The following vaccines have had initial results from phase 3 trials reported in the grey literature and press releases. The information will be added to the living table once results are published in the peer reviewed literature. Recent phase 1 and 2 trial results have been included below, however this is not a complete list of early trial data.

Novavax NVX-CoV2373
  • Over 15,000 participants in UK phase 3 results
  • Primary endpoint is COVID-19 symptomatic disease
  • The final analysis is based on 106 cases and resulted in 89.7% overall vaccine efficacy.
  • Efficacy by strain was calculated to be 96.4% against the original COVID-19 strain and 86.3% against the UK variant strain
  • Analysis of South African Phase 2b study reported 48.6% overall efficacy; and 55.4%% against the South African variant in HIV negative individuals.

Notes

Table includes COVID-19 vaccines published as a peer-reviewed phase 3 trial (preliminary or final results). Data is included on these vaccines from additional publications. Studies that capture outcomes in real world settings are tabulated under effectiveness.

* Preliminary data, not fully established, in some cases small numbers or short follow up, or based on previous data; interpret with caution.

^ Commentary, grey literature, pre peer review or news.

ꝉ Asymptomatic/unreported symptoms. Efficacy estimated by study by pooling all cases and applying to entire cohort of sub studies; interpret with caution.

ⱡ Onward transmission in a vaccinated individual.

ⱶThis figure was not reported in the paper but was included on the same basis of the Moderna results for severe COVID-19.

LD/SD = low dose/standard dose and SD/SD = standard dose

Oxford/Astra-Zeneca has two papers published, (1) and (2).

Modelling studies estimating real world effectiveness are not included in the table.

Where multiple studies are available on an outcome, only the highest quality or most recent are hyperlinked.

Background

Living evidence tables include some links to low quality sources and an assessment of the original source has not been undertaken. Sources are monitored daily but due to rapidly emerging information, tables may not always reflect the most current evidence. The tables are not peer reviewed, and inclusion does not imply official recommendation nor endorsement of NSW Health.

Last updated on 7 May 2021

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