Pfizer Vaccine 88% Effective Against Delta Variant, Study Claims 2 Doses Needed For Protection

Study Shows Pfizer Vaccine Highly Effective In Protecting Against Delta Variant

Singapore has been actively pushing for more people to get vaccinated to better protect themselves and the community.

On Wednesday (21 Jul), a study by the New England Journal of Medicine found that the Pfizer-BioNTech vaccine is highly effective, even against the more transmissible Delta variant.


Based on real-world data, researchers found the vaccine to be 88% effective in preventing Covid-19 symptoms arising from the Delta variant.

Pfizer vaccine reportedly 88% effective against Delta variant

The highly transmissible Delta variant seems to be outdoing other variants, becoming the most dominant Covid-19 strain.

Here in Singapore, it has apparently been responsible for the growing Jurong Fishery Port cluster.

Jurong Fishery Port Infections Likely Came From Foreign Boats, Rules Out Contaminated Fish

In the study published on Wednesday (21 Jul), researchers found that 2 doses of the Pfizer-BioNTech vaccine were nearly as effective against the Delta variant as they were against the previously dominant Alpha variant.

The vaccine was 88% effective in preventing symptomatic disease from the Delta variant.

The study also noted that the vaccine was 93.7% effective against the Alpha variant.

These results came after doubts surrounding its effectiveness against the Delta variant emerged. This, despite the vaccine’s ability to provide much protection against severe disease.

2 doses needed for sufficient protection

The study stressed that a recipient would need 2 doses of the Pfizer-BioNTech vaccine to get sufficient protection against the Delta variant.


With a single dose, the effectiveness only stands at about 36%.

They also made similar findings about the AstraZeneca vaccine. 2 doses proved to be 67% effective against the Delta variant while 1 dose was only 30% effective.

The study then concluded that 2 doses of either vaccine are highly effective against the symptoms of the Delta variant.

Based on the data found, the team supported efforts to maximise vaccine uptake with 2 doses for each individual, especially for more vulnerable individuals.

Singapore on track to reach vaccination goals

As more real-world data emerge, it is becoming increasingly evident that vaccines are key to fighting the Covid-19 battle.

Singapore is now on track for two-thirds of our population to be fully inoculated by National Day.

But we still have room to improve. So if you know of friends or family members who have yet to get vaccinated, do advise them to do so for their own protection.

Have news you must share? Get in touch with us via email at

Featured image adapted from BioSpace.

Sabrina Seng

Sabrina is always facing some form of existential crisis but other than that, she's pretty chill.

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