‘This is good news’: Promising Covid-19 vaccine readies for final testing in the US

A trial from the experimental vaccine showed positive immune responses in all participants

Trial results from a new vaccine were published in The New England Journal of Medicine yesterday with promising results.

The Covid-19 vaccine has been developed by the biotechnology company Moderna in partnership with the US’ National Institutes of Health.

Earlier this year, phase one of the vaccine trial began, implementing a dose escalation plan involving 45 participants (aged 18 to 55).


Two vaccinations were given 28 days apart with various doses (low, medium and high). There were 15 participants in each dose group.

Trial results

The vaccine induced anti–SARS-CoV-2 immune responses in all participants, and no trial-limiting safety concerns were identified.

All participants developed neutralizing antibodies to the virus at levels similar to those seen in people who have naturally recovered from Covid-19.

While over half of the participants experienced a few mild flu-like symptoms like fatigue, chills, headache, muscle pain and pain at the injection site, none were severe enough to be of concern.

“No matter how you slice this, this is good news,” said Dr. Anthony Fauci, the US government’s top infectious disease expert.

The results of phase one of this study will be used to determine the proper dosage needed, which will be examined in phase two and three trials going forward.


An important first step

“This is an essential building block that is needed to move forward with the trials that could actually determine whether the vaccine does protect against infection,” said one of the study’s leaders, Dr. Lisa Jackson of the Kaiser Permanente Washington Research Institute.

She said that in the next two phases, the same two-dose method will be used. “The first dose sort of sets the immune system up, it's called priming,” she explained. 

“So that when you then administer the same thing again, there’s a booster response. There’s an augmented response. So we did not think that one vaccination would be sufficient to get the level of response that we wanted to see.”

On July 27, Moderna is expected to begin phase three of the trial, the largest-scale testing of a potential Covid-19 vaccine yet, involving 30,000 participants.

These participants will be chosen from a more varied pool,  including those in higher age groups, those with chronic health conditions and minority populations.

Going forward


Overall, phase one has shown promising results from Moderna’s Covid-19 vaccine, but there is still a lot to be learned from larger scale testing on higher risk people.

“The safety and immunogenicity data in this preliminary report are promising, and they support continued development of this vaccine,” said Dr. Penny Heaton in an editorial accompanying the study. 

“However, we must bear in mind the complexity of vaccine development and the work still to be done before Covid-19 vaccines are widely available.

“Accelerating the development of Covid-19 vaccine candidates beyond phase 1 depends on continued parallel tracking of activities and fulsome resources.

"The world has now witnessed the compression of 6 years of work into 6 months,” she wrote. “Can the vaccine multiverse do it again, leading to a reality of a safe, efficacious Covid-19 vaccine for the most vulnerable in the next 6?”


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