How Much Protection and Efficacy Rate Do You Get From First Dose of Vaccine?

In the UK, there are 30 million people who already received the first dose of COVID-19. Pfizer, AstraZeneca, and Oxford vaccines are authorized in the country. In the United States, almost 150 million citizens are already vaccinated. The shots came from authorized biopharmaceutical companies, including Moderna, and Pfizer-BioNTech both having a double shot, and Johnson & Johnson variant, which has a single shot per the first dose.

According to a report by Science Alert, the UK is keeping the second dose of vaccines to prioritize remaining citizens to get the first shot. While in the United States, 21 days will be the interval between the first and second dose for Pfizer vaccine, and 28 days for Moderna, as mandated by the Centers for Disease Control and Prevention (CDC).

In reference to the said report, there are differences in measuring the effectiveness of the first and second doses. It depends on the time of conducting the measure, as well as the variant itself.

The data from Food and Drug Administration's late-stage trials is possibly the best data available in terms of the protection effectivity of the doses from each of the authorized vaccines.

60 Percent: Johnson & Johnson

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Johnson & Johnson tested vaccines on severe cases of COVID-19 compared to the symptomatic patients, which the other variants have put on their trials. The protection was activated 14 days after the first shot. After 28 days, the said vaccine exhibited 66.1 percent effectiveness.

The vaccine has a different percentage in some countries. For example, the first shot is 64 to 68 percent effective in South America and 72 percent in the US.

70 Percent: AstraZeneca

Among the CODIV-19 vaccine variants, AstraZeneca was the hardest to measure. This is due to the various research designs in the late-stage trials of the vaccine. In addition, a more extensive study for the vaccine is still ongoing. Because of this, the FDA hasn't yet posted any data from AstraZeneca's shots.

One of the late-stage trial's results was published by The Lancet. The data shows a 76 percent effectivity rate in at least 90 days.

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80 Percent: Moderna

Due to the low count of individuals who caught COVID-19 during the clinical trials, the percentage of effectiveness from the Moderna vaccine jumps from 43 percent to 84 percent.

Along with the effectiveness rate of the shots, the Moderna vaccine already protects at a rate of 69.5 percent in just 13 days after the first shot. However, the second shot of the vaccine was not received by 7 percent of the individuals included in the trial. One possible reason is that this same group experienced 50 protection after 14 days of the first shot and a 92 percent protection rate after the second shot.

80 Percent: Pfizer-BioNTech

The Pfizer vaccine's protectivity efficacy is 52 percent between the first and last shot. The figure is theorized to be much higher because the percent figure includes the first 11 days before the protection even starts to take effect. Like Moderna, Pfizer included individuals who haven't got COVID-19 during the trials, so the results of effectivity jump from 19 to 84 percent.