Current Affairs

Issue

US drug-maker Pfizer’s preliminary data from late-stage human trials of the Covid-19 vaccine has been found more than 90% effective. 

Background

The findings are critical as the vaccine is headed for a review by the US Food and Drug Administration (FDA) later this month.

Details

• The phase 3 trial of the vaccine candidate, BNT162b2, began on July 27 and has so far enrolled 43,538 participants, 38,955 of whom had received a second dose as of November 8.

• This vaccine was developed using mRNA technology which makes use of the messenger RNA molecules that tell cells what proteins to build.

• The mRNA, in this case, is coded to tell the cells to recreate the spike protein of the novel coronavirus.

• Once the mRNA is injected into the body, the cells will use its instructions, creating copies of the spike protein, which is in return expected to prompt the immune cells to create antibodies to fight it.

• Unlike several other vaccine candidates, mRNA vaccines are synthetically developed and they don’t need the virus to be cultivated and replicated, just the code for the most crucial part that the body’s immune system is to target. 

• After getting the code for the virus, it is possible to develop the vaccine within weeks for pre-clinical testing, compared with months taken for more traditional platforms.

• The vaccine was more than 90% effective in preventing Covid-19 among participants who had received a second dose as opposed to those participants who had only received a placebo.

Issue

US Pharma giant Pfizer and German biotechnology company BioNTech’s, which are testing four vaccine candidates for Covid-19 as part of Project Lightspeed, released the phase-1 data for one of these, being tested in the US.

Background

The study said that across all populations, the candidate was well-tolerated and demonstrated a strong immune response, and that they are on track to seek regulatory review in October 2020.

Details

• The project with four vaccine candidates is based on BionTech’s proprietary mRNA-based technology platforms. It began in mid-January after the genetic sequence of SARS-CoV-2 was made public.

• Two of these four candidates — BNT162b1 or BNT162b2 — have gone into human trials so far. Both are in Phase 1/2 human trials in the United States and Germany.

• The researchers announced that after extensive review of preclinical and clinical data and in consultation with the US FDA’s Center for Biologics Evaluation and Research, they have chosen to advance their BNT162b2 vaccine candidate into the Phase 2/3 study, where 30,000 participants will be taking part.

  BNT162b2

• It is a single nucleoside-modified messenger RNA (modRNA) vaccine candidate. It is made of a short segment of genetic material — the messenger RNA — which provides instructions for a human cell to make a harmless version of a target protein, in this case the spike protein of SARS-CoV-2, in order to activate an immune response against the protein.

• During a clinical trial, three aspects are assessed: reactogenicity (ability to produce common, adverse reactions), immunogenicity (ability to provoke an immune response), and safety.

• BNT162b2 was associated with less systemic reactogenicity, particularly in older adults. This effectively means that BNT162b2 generates an even lower adverse reaction among the vulnerable population, making it the safer candidate of the two.