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Real-life data confirms: two doses of the Pfizer vaccine confers 95% protection

It's excellent performance for any vaccine, let alone one done in less than one year with innovative technology.

Mihai Andrei
May 26, 2021 @ 3:45 pm

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Real-life data from the US and Israel confirms what Pfizer’s clinical trials found: the vaccine offers protection from the vast majority of COVID-19 cases. It’s the first time vaccine efficacy for COVID-19 has been confirmed in such a big sample size.

Image credits: Marko Verch.

This time last year, we were scrambling and fearing that a working vaccine may be much more than a year away. Now, we not only have a working vaccine — we have several, and vaccine campaigns are well underway in many countries.

The first that hit the scene in large-scale trials was the Pfizer vaccine. Researchers working on the vaccine claimed that it offers around 95% protection. Now, as the real data from Israel is coming in, the figures seem to be confirmed.

Two weeks after receiving both doses, vaccinated Israelis were 95.8% less likely to fall ill, and 98.9% less likely to be hospitalized. Simply put, two doses of the Pfizer vaccine work just as expected, the study concluded. The vaccine also works very well against the B.1.1.7 (British) variant. The study was carried out on 600,000 participants.

“Two doses of BNT162b2 are highly effective across all age groups (≥16 years, including older adults aged ≥85 years) in preventing symptomatic and asymptomatic SARS-CoV-2 infections and COVID-19-related hospitalisations, severe disease, and death, including those caused by the B.1.1.7 SARS-CoV-2 variant.”

However, we shouldn’t rely on a single Pfizer dose for protection. A single dose was found to offer 58% protection against infection and 76% protection against hospitalization — which strongly suggests that a second dose is crucial.

There’s hope for a post-pandemic world

Overall, however, the results are more than encouraging. For the first time since the start of the pandemic, we’re starting to see a light at the tunnel. We’re not there yet (Israel is a global leader in COVID-19 vaccination), but other countries are catching up, and with a sufficient vaccination coverage, we may gain some semblance of normalcy.

“These findings suggest that high vaccine uptake can meaningfully stem the pandemic and offers hope for eventual control of the Sars-CoV-2 outbreak as vaccination programmes ramp up across the rest of the world,” the study authors wrote.

However, there’s always the risk of one mutation reducing vaccine efficacy. This is why the vaccination race is a global effort — regardless of one or several countries’ success, if others are left behind, no one will truly be safe, as new variants can emerge.

Also, the Pfizer vaccine is one of the more expensive ones, and one that’s the most difficult to transport (as it requires ultra-cold storage). We won’t vaccinate the world with Pfizer (at least not this year), but thankfully, we have other effective vaccines as well.

As other countries are ramping up their respective vaccination campaigns, new real-life studies will hopefully confirm the effectiveness of other vaccines.

In the meantime, it’s likely that even those vaccinated will need to take booster shots, much like we do with existing influenza vaccines.

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