Sat. May 30th, 2020

First COVID Vaccine Tested on Humans Shows Positive Results

COVID Vaccine

Moderna,  an American clinical-stage biotechnology company, informed through a press release on 18 May 2020 that it has successfully conducted tests of the COVID vaccine in the 1st phase. It said the vaccine namely  mRNA-1273  has shown positive interim clinical data against novel coronavirus (SARS-CoV-2). This confirmation came after a study led by the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health (NIH).

 

As per the news release, the Immunogenicity data are presently available for the 25 µg and 100 µg dose level (ages 18-55) after two doses (day 43) and at the 250 µg level (ages 18-55) after one dose (day 29). The study observed that the dose-dependent increases in immunogenicity found across the three dose levels and between prime and boost within the 25 µg and 100 µg dose levels.

All participants in the trial were aged 18-55 (n=15 per cohort) across all three dose levels seroconverted by day 15 after a single dose. On day 43, two weeks following the second dose, at the 25 µg dose level (n=15), levels of binding antibodies were at the levels seen in convalescent sera (blood samples from people who recovered from COVID-2019) tested in the same assay. On day 43, at the 100 µg dose level (n=10), levels of binding antibodies significantly exceeded the levels seen in convalescent sera. However, no samples were available for the remaining participants.

 

By the time Moderna announced the 1st phase testing of the COVID vaccine, data were available only for the first four participants in each of the 25 µg and 100 µg dose level cohorts. Consistent with the binding antibody data, mRNA-1273 vaccination elicited neutralizing antibodies in all eight of these participants, as measured by plaque reduction neutralization (PRNT) assays against live SARS-CoV-2. The levels of neutralizing antibodies on day 43 were at or above levels generally seen in convalescent sera.

 

The study noted that mRNA-1273 meant for COVID vaccine was generally safe and well-tolerated.

 

The sole incidence of a grade 3 adverse event in the 25 µg and 100 µg dose cohorts was a single participant at 100 µg who experienced grade 3 erythema (redness) around the injection site. To date, the most notable adverse events were seen at the 250 µg dose level, comprising three participants with grade 3 systemic symptoms, only following the second dose. All adverse events have been transient and self-resolving. No grade 4 adverse events or serious adverse events have been reported.

 

Preclinical results from a viral challenge study in mice conducted in collaboration with NIAID and its academic partners are also available. In this study, vaccination with mRNA-1273 prevented viral replication in the lungs of animals challenged with SARS-CoV-2. Neutralizing titers in Phase 1 clinical trial participants at the 25 µg and 100 µg dose levels were consistent with neutralizing titers that were protective in the mouse challenge model.

 

Based on the interim Phase 1 data, the Moderna-led Phase 2 study will be amended to study two dose levels, 50 µg, and 100 µg, with the purpose of selecting a dose for pivotal studies. The NIAID-led Phase 1 study is being amended to include a 50 µg dose level cohort across each of the three age groups.

 

Moderna anticipates the dose for the Phase 3 study to be between 25 µg and 100 µg. The company expects the Phase 3 trial initiation in July.  However, it depends upon the finalization of the clinical trial protocol.

 

“These interim Phase 1 data, while early, demonstrate that vaccination with mRNA-1273 elicits an immune response of the magnitude caused by natural infection starting with a dose as low as 25 µg,” informed Tal Zaks, M.D., Ph.D., Chief Medical Officer at Moderna.

 

“When combined with the success in preventing viral replication in the lungs of a pre-clinical challenge model at a dose that elicited similar levels of neutralizing antibodies, these data substantiate our belief that mRNA-1273 has the potential to prevent COVID-19 disease and advance our ability to select a dose for pivotal trials.”

 

“With today’s positive interim Phase 1 data and the positive data in the mouse challenge model, the Moderna team continues to focus on moving as fast as safely possible to start our pivotal Phase 3 study in July and, if successful, file a BLA,” proclaimed Stéphane Bancel, Chief Executive Officer at Moderna. “We are investing to scale up manufacturing so we can maximize the number of doses we can produce to help protect as many people as we can from SARS-CoV-2.”

 

Funding from the Biomedical Advanced Research and Development Authority (BARDA), a division of the Office of the Assistant Secretary for Preparedness and Response (ASPR) within the U.S. Department of Health and Human Services (HHS), supported the planning for the Phase 2 and Phase 3 studies of mRNA-1273 and will also support the execution of these studies, as well as the scale-up of mRNA-1273 manufacturing both at the Company’s facilities and that of its strategic collaborator, Lonza Ltd.

 

Immunogenicity data are currently available for the 25 µg and 100 µg dose level (ages 18-55) after two doses (day 43) and at the 250 µg level (ages 18-55) after one dose (day 29). Dose-dependent increases in immunogenicity were seen across the three dose levels, and between prime and boost within the 25 µg and 100 µg dose levels.

 

All participants ages 18-55 (n=15 per cohort) across all three dose levels seroconverted by day 15 after a single dose. At day 43, two weeks following the second dose, at the 25 µg dose level (n=15), levels of binding antibodies were at the levels seen in convalescent sera (blood samples from people who have recovered from COVID-19) tested in the same assay. At day 43, at the 100 µg dose level (n=10), levels of binding antibodies significantly exceeded the levels seen in convalescent sera.

 

Samples of remaining participants are not available yet though.

 

Moderna currently has nine development candidates in its prophylactic vaccines modality, including:

Vaccines against respiratory infections

  • Respiratory syncytial virus (RSV) vaccine for older adults (mRNA-1777 and mRNA-1172 or V172 with Merck)
  • RSV vaccine for young children (mRNA-1345)
  • Human metapneumovirus (hMPV) and parainfluenza virus type 3 (PIV3) vaccine (mRNA-1653)
  • Novel coronavirus (SARS-CoV-2) vaccine (mRNA-1273)
  • Influenza H7N9 (mRNA-1851)

Vaccines against infections transmitted from mother to baby

  • Cytomegalovirus (CMV) vaccine (mRNA-1647)
  • Zika vaccine (mRNA-1893 with BARDA)

Vaccines against highly prevalent viral infections

  • Epstein-Barr virus (EBV) vaccine (mRNA-1189)

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