The Major Covid19 Vaccines – What’s the Difference?

There are currently more than 230 vaccine candidates using a range of methods to activate antibodies and virus-fighting cells to resist infection. Several have either been licensed for use or are awaiting approval, and vaccinations are taking effect in many countries.

In this article, we want to give you a very brief summary of the top contenders currently making headlines in the Covid19 cycle. The ranking is not based on an opinion of which is ‘best’, but on current popularity and width of distribution. For more information as to definitions and types of technologies used in the various vaccines, another article will follow later in the coming week.

These are the main vaccines currently being used around the world:

1. BioNTech/Pfizer (In Use in Malta)

One of the prominent vaccines being used in the fight against Covid19, and having been the first one to be approved for use, the mRNA jab is on course to have 2 Billion doses during 2021 and is being distributed to the UK, EU, US, Israel and Japan, with approvals in over 45 countries. A 95% efficacy rating makes it one of the strongest contenders in the ring.

The vaccine is one of the more ‘high-maintenance’ of them all – it must be transported at -75C, a characteristic which, added to the fact that it must be taken in 2 separate doses, will make it harder to roll out to less developed regions. It also has a lifespan of around5 days when kept at temperatures between 2C and 8C.

2. Moderna (In Use in Malta)

Although it came second in the race to have its vaccine approved, the jab is rising in popularity as most developed countries around the world are looking for ways to acquire doses. Estimates show that as many as 1 Billion doses can be produced throughout this year, but even so, it is set to deliver twice the amount of doses to the US than Pfizer. Efficacy is currently rated at around 94.1%, a number which does not seem to be dropping off too much in the face of new, worrying variants of the virus.

A bit easier to handle, logistics-wise, than the previously mentioned vaccine, the Moderna jab has to be transported at -20C and can last up to a month when kept between 2C and 8C.

3. AstraZeneca/Oxford University (In Use in Malta)

Once the pack leader, this vaccine has met several stumbling blocks on its path to widespread distribution. Questions have arisen though, as to its real efficacy. Unlike the two vaccines already mentioned, which make use of mRNA technology, the AstraZeneca vaccine comes in the form of an Adenovirus and should be taken in 2 doses, up to 12 weeks apart. Phase 3 trials showed an underwhelming figure of 70% efficacy, but regulators have raised doubts as to what it causing a significant swing in that figure, to as low as 62%, as high as 90%, depending on dosage.

Not all is dim though, this vaccine does not need to be frozen and can be refrigerated between 2C and 8C without expiring – a quality that, in tandem with the expectancy of 3 Billion doses being manufactured throughout this year, gives hope for worldwide distribution, especially in developing countries.

4. Johnson & Johnson

A veteran in the medical sector, Johnson & Johnson were held back by incessantly low efficacy ratings throughout small scale trials. But now, they seem to be preparing for worldwide rollout as their single dose Adenovirus enters phase 3 trials in several countries, with an efficacy rating of 66% seeming to be the predominant result.

Albeit being a relatively low number, it is still considered a successful vaccine – its single dose delivery system and ability to be transported at 2C to 8C for around 3 months, only add onto that notion. Estimates show that around 1 Billion doses of this vaccine will be produced within 2021.

5. Gamaleya

Most commonly known as the Sputnik V, the Research Institute’s vaccine is proving to be one of Russia’s more successful gambles throughout this pandemic. With efficacy ratings of 95% being confirmed by several research groups around the world. Having been launched before Phase 3 trials had even started, the dual dose Adenovirus jab received emergency approvals in several countries, and had it not been for a limitation in production capacity, would have been rolling out in masses by now.

Production estimates currently stand at around 1.2 Billion doses, but if the country’s efforts to secure wider capacity for production, figures could make it one of the most widely produced vaccines in the world. Storage is also favourable, with a capability of being stored at 2C to 8C in a dehydrated form, and -20C in liquid form, for up to 6 months.

6. Novavax

An up and coming player in the world of vaccines, Novavax is promising to deliver a widely distributed dual dosage recombinant spike protein vaccine throughout the coming year. Around 2 Billion doses are expected to be produced in 2021 in fact, with transportation being relatively simple due to its stability at 2C to 8C for around 6 months.

Other potentially major vaccines to be made available in the coming weeks and months include; Medicago, CureVac, SinoVac, Bharat Biotevch


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