Out of the four COVID-19 vaccines that Pfizer is developing, the very first trials have come out very positive. This comes at a time when COVID-19 cases are spiking across the world, as all hopes rest on a potential vaccine to end the pandemic.

Earlier this month, preliminary results of the vaccine candidate trials were released by the company saying that it triggered a strong immune response. A Pfizer's COVID-19 vaccine developer Phil Dormitzer told ABC News that the company's vaccine candidate elicited neutralizing antibodies that are "equivalent to or better than" what's seen in people who had COVID-19.

Pfizer and BioNTech are partnering to produce 100 million doses of the vaccine in 2020, he added. However, they need regulatory approval to execute their plans.

No Severe Side Effects: Study

Vaccine Human Trial
Vaccine (Representational Picture) YouTube Grab

According to a study that Pfizer published in the preprint server medRxiv, after the combined Phase 1 and 2 vaccine trials none of the participants suffered severe side effects. However, half of those who received a second dose of the vaccine reported adverse reactions like fever or sleep disturbance.

About 45 healthy adults, between 18 and 55 in age were subjected to the vaccine trials, while nine of them received a placebo. Others were divided into three equal groups, as they were given 10-microgram, 30-mcg, or 100-mcg doses of the vaccine candidate.

After three weeks, they were given a second dose to the 10-mcg and 30-mcg groups. The 100-mcg group was not given a second dose as they developed a fever after the first shot itself, meaning the dose was very high. Just seven days after the second dosage was administered, the 10-mcg and 30-mcg groups had significant levels of COVID-19 antibodies, high enough to neutralize the novel coronavirus.

What Next?

SARS-CoV-2
SARS-CoV-2 Wikimedia Commons

Now, Pfizer is set to start a combined Phase 2b and 3 trials, involving almost 30,000 healthy participants after approval from authorities. The study results are yet to be peer-reviewed. The latest trial's sample size was small and it is yet to be known if the Pfizer vaccine would generate antibodies in groups such as minors, seniors, and pregnant women.

This vaccine candidate uses a gene-based technology that induces the creation of antibodies, called messenger RNA (mRNA), similar to Moderna. It is also easy to manufacture. Pfizer is ambitious to manufacturing 1.2 billion doses by 2021, while FDA has not approved even a single mRNA vaccine until now.