How the Moderna, AstraZeneca, Pfizer and other Covid vaccines compare

Which vaccines has the UK ordered?

The UK has ordered vaccines from:

The Pfizer, Oxford/AstraZeneca and Moderna vaccines are in use, while J&J and Novavax have both published phase three data and should be approved soon. The GSK/Sanofi and Valneva jabs are still in development. 

How effective are they?

Going by clinical trial results alone the Pfizer/BioNTech and Moderna jabs are the most effective – scoring 95 per cent and 94.1 per cent respectively. However, as data from mass administration of the vaccines begin to emerge we are getting a clearer picture.

Research on the Pfizer vaccine from Israel – the country that has vaccinated the biggest proportion of its population so far – appears to back up the trial data. Evidence showed that just 0.04 per cent of people who received two doses of this jab developed Covid. And a separate study comparing vaccinated and unvaccinated people found that the vaccine offered 92 per cent efficacy.

Another study by Israel’s Clalit Research Institute and Harvard University found two doses of the Pfizer vaccine reduced symptomatic Covid-19 by 94 per cent and severe disease by 92 per cent. A single dose reduced symptomatic Covid-19 by 57 per cent and severe disease by 62 per cent after three weeks. 

Pfizer is seeking approval from regulators for use of its jab in young people aged 12 to 15 after it reported interim results showing that its jab is 100 per cent effective and well tolerated in this age group. 

The UK has also begun to report good news from its successful immunisation programme. Data from Public Health England‘s (PHE) Siren study, published on Feb 22, also showed that those given the jab had at least a 70 per cent lower chance of becoming infected with coronavirus three weeks after vaccination, rising to 85 per cent after a second dose.

And another study, published on Mar 1, showed that a single dose of either the Pfizer/BioNTech or the Oxford/AstraZeneca vaccine provides a high level of protection against severe disease in the most vulnerable age-groups, with approximately 80 per cent protection against hospitalisations in the over 70s. AstraZeneca later said its jab showed 85 per cent efficacy against symptomatic Covid-19 in patients aged 65 years and over, an increase of five per cent, after the firm updated analysis of the third phase of testing.

​The AstraZeneca vaccine is 100 per cent effective against severe or critical disease and hospitalisation, a US study published on Mar 22, has shown. Some 32,449 people across all age groups took part in the phase three trial in the US, Chile and Peru, with a total of 141 cases of symptomatic Covid-19 reported.

The study also showed that the jab was 79 per cent effective at preventing symptomatic illness, although the company later revised the that figure down to 76 per cent after American authorities raised concerns that results reported from its US trial were outdated.

However, crucially the new trial was conducted when worrying new variants were sweeping through populations, and so demonstrates it is just as effective. 

Other vaccines do not yet have such strong real-world data to back up trial results. The J&J vaccine – which was tested in the United States, South Africa and several Latin American countries – had 66 per cent efficacy overall, this varied depending where it was tested. For example, in the US the vaccine achieved 72 per cent efficacy, but in South Africa – where a new variant is running rampant – it was just 57 per cent.

But, Dr Anthony Fauci, leader of the US response, pointed out that none of the trial participants who took the vaccine – either in the US, South Africa or Latin America – were hospitalised or died. 

“The most important thing is to keep people outside hospital and prevent them getting severe disease,” he said. 

What about efficacy among older people?

Older people are at more risk from Covid but immune responses tail off as people age and vaccine efficacy wanes. 

Most of the studies that looked at different age groups only compared over 60s and over 65s to the rest of the study population – there is a world of difference between a healthy 60-year-old and a 90-year-old chockablock with comorbidities. 

And the number of older adults included in trials are too small to draw firm conclusions.  Several European countries, including France and Germany, have said the AstraZeneca vaccine should not be given to the over 60s or 65s – this is because of a lack of evidence in this age group, rather than because they think the jab is ineffective.

However, the real-world data from the UK, is beginning to prove that doubts over the jab’s effectiveness among older people are unfounded. 

How long does immunity last after vaccination?

There is currently no reliable test to indicate how long immunity lasts after any of the vaccines. The only clue we can get is to look at immunity conferred by the virus itself with various studies suggesting it lasts several months, with one last November suggesting it could last at least eight months or even years.

Reinfection has also – so far – been relatively rare and a UK study of 20,000 health workers showed  that immune responses from past infection reduce the risk of catching the virus again by 83 per cent for at least five months.

However, immunity against other coronaviruses – such as the common cold – wanes over time so booster shots are likely to be needed as most experts believe this virus is not going away. The emergency of new variants may also make further jabs necessary. 

How effective are the vaccines against the variants?

Some experts believe the Covid vaccine may have to be reformulated annually – like the flu vaccine – to combat what is known as “antigenic drift”, or the emergence of new variants. 

A study carried out by the developers of the Pfizer-BioNTech jab found that it elicited good antibody responses against engineered viruses with similar mutations to the UK and South African variants. But other vaccines tested on populations where the variants were circulating – J&J, Moderna and Novavax – have shown they are less effective against the South African variant.

However, they all provide some protection and are more effective against severe illness. 

South Africa announced that it was pausing its vaccination programme after a study found that the Oxford-AstraZeneca vaccine was not effective at preventing mild to moderate disease. However, many experts pointed out that this study was small and only looked at individuals aged under 65. 

The Moderna and Pfizer vaccines are based on mRNA technology and are the easiest to tweak, with Dr Ugur Sahin, CEO of BioNtech, estimating it could take just six weeks to adapt the vaccine

Vaccines based on more conventional technology are less adaptable and researchers at the Oxford University say a tweaked version won’t be ready until September

However, most experts caution against viewing vaccines through an “all or nothing” prism – even if they offer only 50 per cent protection against the variants that will be better than not being vaccinated at all. 

Second-generation vaccines are currently in development, with UK and German firms GSK and Curevac collaborating on a multi-valent vaccine that can be used against several strains. 

What about ease of use?

Other considerations should also be taken into account when comparing vaccines.

The Pfizer vaccine now no longer needs to be kept at deep freeze conditions – between minus 60 and 80 degrees Celsius – and can be stored in a standard medical freezer at between -15C and -25C for as long as two weeks.  

However, other vaccines – including AstraZeneca – can be kept at normal refrigerator temperatures. 

The J&J vaccine is administered in just one shot – although the company is also trialling a booster dose – so would be appropriate for remote locations or where transport is a challenge. 

The AstraZeneca vaccine is cheap and is being made available at cost to low and middle income countries in perpetuity. 

Do they have side effects?

The main side effects from vaccines are immediately post vaccination and include tenderness, swelling and/or redness at the injection site, headache, muscle ache, fatigue and fever. 

However, there have been concerns about the AstraZeneca vaccine after several European countries reported a link between it and serious blood clots. Several European countries, including Germany, France and Spain, suspended use of the vaccine following reports of people dying from blood clots post vaccination, including one British man.

In a rapid review of the jab European Medicines Agency declared it “safe and effective”. In a briefing on April 7, the EMA concluded that blood clots should be listed as a “very rare” side effect, and restated that its benefits far outweigh any risk.

Further to the review, the UK’s Medicines and Healthcare Regulatory Agency stated that there is a four in one million chance of getting a blood clot from the AstraZeneca vaccine. Despite the negligible risk, those aged under 30 in the UK will be offered Pfizer or Moderna instead.

The UK regulator stood by the vaccine despite the European suspension but now says anyone who experiences a headache for more than four days after having the  jab should seek medical attention.

People should also get help if they have bruising somewhere other than the injection site after a few days, it added.

The UK government has insisted that it is “100 per cent confident” in the effectiveness of the Oxford-AstraZeneca vaccine. While Number 10 said the jab was “safe, effective and has already saved thousands of lives”.

What is the vaccination programme’s progress so far?

Everyone aged 50 and over has been invited to get the first dose of the vaccine, as over half of all adults in the UK have now been vaccinated.

The Telegraph has exclusively reported that those over 70 and those who work in the NHS will receive a booster jab to protect them against coronavirus variants from September. 

In an interview with The Telegraph, Nadhim Zahawi, the vaccines minister, revealed the first booster doses will go to people in the top four priority groups for the original rollout – those aged over 70 as well as frontline NHS and social care workers.

As of Mar 30, 30,680,948 first doses have been administered in the UK, and over 3.8m people have received a second dose so far. 

Mr Johnson has said every person aged over 18 in England will have been offered a coronavirus vaccination by the end of July. This target comes after the government reached its target of vaccinating those in the top four JCVI priority groups by mid-February.

However, people in their 40s are likely to have to wait until May to get their Covid-19 vaccine after problems with a shipment of the AstraZeneca jab from India impacted supply.

“significant reduction” in jabs from Mar 29 means the focus for the NHS in April will be on giving second doses to people who were vaccinated earlier in the year. Matt Hancock said the estimated 12 million second doses of the Covid-19 vaccine “cannot be delayed” as they have to be delivered within 12 weeks of the first dose. 

But the Health Secretary also clarified that there will be no weeks in April with no first doses of the Covid-19 vaccine administered, and no cancellation of appointments as a result of supply issues. 

The current shortage is understood to have been triggered by the late delivery of five million doses of the AstraZeneca jab being manufactured in India, and the need to retest a batch of 1.7 million doses. In total, India’s Serum Institute was due to send 10 million doses to the UK this month – but just half have arrived, with the five million due at the end of March now delayed by four weeks. 

The JCVI also stated that those in the 30-39 and 18-29 age groups will be next in line to receive a vaccine, once those aged 40 and over have been sent an invite to be vaccinated. 

Can I buy the vaccine?

Not in the UK. The Covid-19 vaccine is currently being offered by the NHS to the people most at risk of coronavirus. Representatives of Pfizer have stated that they have no plans to supply the vaccine to the private sector, and private vaccination during the first wave of vaccinations is highly unlikely. 

What about cost?

Comparing cost is a murky business – the UK has not published vaccine contract details or costs because of “commercial sensitivities” and different countries have negotiated different prices that don’t always make sense. South Africa is paying twice what European countries are paying for the AstraZeneca vaccine, for example. 

In December, a Belgian minister tweeted the price the European Union was paying for the leading vaccines which gives some indication over price per dose.

However, recent EU attacks on the AstraZeneca have called into question the decision not to profit from the coronavirus vaccine. In a Telegraph exclusive, Sir John Bell of the AstraZeneca team warned that the company may decide to stop charging the vaccine at cost price due to damaged team morale.

  • Oxford/AstraZeneca: €1.78 (£1.61)
  • Johnson & Johnson: $8.50 (£6.30)
  • Sanofi/GSK: €7.56 (£6.63)
  • Pfizer/BioNTech: €12 (£10.53).
  • CureVac: €10 (£8.77)
  • Moderna: $18 (£12.96)

What do we know about China’s Sinovac and Sinopharm vaccines?

Sinovac is one of four Chinese vaccines in last-stage human trials, a higher number than any other nation in the world.

Some are concerned about the quality of the vaccines and on Nov 9, Sinovac was forced to suspend trials of its vaccine in Brazil after a participant died.

Clinical trials in Brazil reported on Jan 13 that Sinovac was 50.4 per cent effective, only slightly above the World Health Organisation’s minimum standard of 50 per cent.

On Jan 11, Indonesia became the first country outside China to grant emergency approval to Sinovac’s vaccine, amid surging infections and deaths, followed two days later by Turkey. Interim data showed it is 65.3 per cent effective, Indonesia’s food and drugs authority said.

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