AstraZeneca, Janssen, Moderna and Pfizer: How do the different vaccines compare?

As the AstraZeneca vaccine has been restricted for use in over-60s and the use of the Johnson & Johnson vaccine has been paused, there has been much talk on the difference between all the different jabs. 

Ireland currently has four Covid-19 vaccines from Pfizer, Moderna, AstraZeneca and Johnson & Johnson. 

So, how do the four different vaccines compare to one another? 

Janssen/ Johnson and Johnson 

Dubbed a “game-changer” vaccine due to it being a single dose jab, the Johnson and Johnson vaccine has been paused for use in Ireland as the Food and Drug Administration (FDA) in the United States is reviewing six reported cases of blood clots in 6.8 million doses administered. 

It has an overall 66pc efficacy rate and a 57pc efficacy rate against the South African variants. There is currently no data on the UK variant.

A total of 606,000 doses have been scheduled to arrive in Ireland between April and June. As the vaccine has currently been paused for use, Ireland will be waiting on a green light from the European Medicines Agency (EMA) on if it's safe for us. 

It is an Adenovirus vaccine which means it doesn’t have to be stored at really low temperatures like the mRNA vaccines.

These type of vaccines have been used in labs for decades and uses a virus as a delivery system to allow our immune system to see spike protein. So, basically our immune system can learn to respond to it and develop an immune response to not get sick with Covid-19. 

Oxford/AstraZeneca

The AstraZeneca vaccine is also an Adenovirus vaccine. 

It has currently been suspended for use in under 60s in Ireland due to a rare side effect of blood clotting. 

The chance of a blood clot from the jab is between four and ten in every one million people, one of whom may die. 

The efficacy rate of the AstraZeneca vaccine is 76pc and the current wait time between dose one and two is 12 weeks. 

It has the same efficacy against the UK variant but is lower against mild to moderate illness from South African variants. 

A total of 813,000 doses are scheduled to arrive in the country between April and June. 

Pfizer

The Pfizer vaccine has an overall efficacy rate of 95pc. 

This two-dose mRNA vaccine is also effective against the UK and South African variants. 

A downside to the mRNA vaccines is that they need to be stored in extremely cold temperatures. 

Currently, in Ireland, people receiving the Pfizer vaccine have a 28-day wait between the first and second doses. 

The country is scheduled to receive 2.218 million doses and an additional 540,000 has been promised between April and June. 

Moderna

Also and mRNA vaccine, Moderna has an overall efficacy rate of 94.1pc. 

It also requires two doses with the current wait between doses in Ireland being 28 days. 

It is also effective against the UK variant but has reduced efficacy against South African variants. 

A total of 383,000 doses of the Moderna vaccine are expected to arrive into the country between April and June.

 

Online Editors